JP2015050738A - Decoder and decoding method, encoder and encoding method - Google Patents

Abstract

An encoding efficiency can be improved by optimizing orthogonal transform. An orthogonal transform coefficient obtained by orthogonal transform of a difference between a predicted image of an image and an image in TU units is received. The determination unit determines an inverse orthogonal transform method for the received orthogonal transform coefficient in units of TUs according to a distance between the TU and a neighboring image adjacent to the predicted image in the inverse orthogonal transform direction. The inverse orthogonal transform unit performs inverse orthogonal transform on the orthogonal transform coefficient in units of TUs using the determined inverse orthogonal transform method. The present disclosure can be applied to, for example, a decoding device. [Selection] Figure 14

Description

  The present disclosure relates to a decoding apparatus and a decoding method, and an encoding apparatus and an encoding method, and in particular, a decoding apparatus and a decoding method capable of improving encoding efficiency by optimizing orthogonal transform, and The present invention relates to an encoding device and an encoding method.

  In recent years, devices based on MPEG (Moving Picture Experts Group phase) such as orthogonal transform such as discrete cosine transform and compression by motion compensation using redundancy unique to image information, information distribution such as broadcasting stations, And the reception of information in general households.

  In particular, the MPEG2 (ISO / IEC 13818-2) system is defined as a general-purpose image encoding system. MPEG2 is a standard that covers both interlaced scanning images and progressive scanning images, as well as standard resolution images and high-definition images. MPEG2 is currently widely used in a wide range of applications for professional and consumer applications. By using the MPEG2 system, for example, a code amount of 4 to 8 Mbps is assigned for a standard resolution interlaced scan image having 720 × 480 pixels, and 18 to 22 MBps is assigned for a high resolution interlaced scan image having 1920 × 1088 pixels. Therefore, it is possible to realize a high compression rate and good image quality.

  MPEG2 was mainly intended for high-quality encoding suitable for broadcasting, but did not support encoding methods with a lower code amount (bit rate) than MPEG1, that is, a higher compression rate. With the widespread use of mobile terminals, the need for such an encoding system is expected to increase in the future, and the MPEG4 encoding system has been standardized accordingly. As for the MPEG4 image coding system, the standard was approved as an international standard in December 1998 as ISO / IEC 14496-2.

  Furthermore, in recent years, for the purpose of image coding for the initial video conference, The standardization of 26L (ITU-T Q6 / 16 VCEG) is in progress. H. 26L is known to realize higher encoding efficiency, although a larger amount of computation is required for encoding and decoding than encoding methods such as MPEG2 and MPEG4.

  In recent years, as part of MPEG4 activities, Based on 26L, H. Standardization to achieve higher encoding efficiency by incorporating functions not supported by 26L was performed as Joint Model of Enhanced-Compression Video Coding. This standardization was implemented in March 2003 by H.C. It was internationally standardized under the name of H.264 and MPEG-4 Part 10 (AVC (Advanced Video Coding)).

  Furthermore, as an extension, RGB, 4: 2: 2 and 4: 4: 4 color difference signal format and other necessary coding tools for business use, 8 × 8DCT (Discrete Cosine Transform) specified by MPEG2, Standardization of FRExt (Fidelity Range Extension) including quantization matrix was completed in February 2005. As a result, the AVC method has become an encoding method capable of well expressing film noise included in movies, and has been used for a wide range of applications such as BD (Blu-ray (registered trademark) Disc).

  However, these days, we want to compress images with a resolution of about 4000 x 2000 pixels, which is four times that of high-definition images, or to deliver high-definition images in environments with limited transmission capacity such as the Internet. Needs are growing. For this reason, in the VCEG (Video Coding Expert Group) under the ITU-T, studies on improving the coding efficiency are continuing.

  In addition, for the purpose of further improving the coding efficiency compared to AVC, HEVC (High Efficiency Video Coding) is being developed by JCTVC (Joint Collaboration Team-Video Coding), a joint standardization organization of ITU-T and ISO / IEC. The standardization of the encoding method called is being advanced. As of August 2013, Non-Patent Document 1 has been issued as Draft.

  By the way, in HEVC Version 1, the encoding target is limited to an image of an 8-bit or 10-bit 4: 2: 0 color difference signal format.

  Non-Patent Document 2 proposes standardization for handling images of other color difference signal formats such as 4: 2: 2, 4: 4: 4, and RGB, and images having a larger bit depth as encoding targets. Based on the method, it is being promoted as HEVC Version 2.

  The method proposed in Non-Patent Document 2 is basically a natural extension of HEVC version 1. However, in this method, for example, when the encoding target is an image in the 4: 2: 2 color difference signal format and the PU (Prediction Unit) of the luminance signal is 32 × 32 pixels, 16 × 32 pixels of the color difference signal It is necessary to perform non-square orthogonal transform (NSQT (Non-Square Quadtree Transform)) with TU as a transform unit. In this specification, a block in which the number of pixels in the horizontal direction is X and the number of pixels in the vertical direction is Y is represented as “X × Y pixels”.

  In Non-Patent Document 3, for example, when the encoding target is an image of a 4: 2: 2 color difference signal format and the luminance signal PU is 32 × 32 pixels, the 16 × 32 pixel PU of the color difference signal is It has been proposed to divide into two 16 × 16 pixel square TUs and perform orthogonal transformation in units of TUs. By doing so, compatibility with HEVC version 1 is maintained, and there is no need to perform non-square orthogonal transform.

Benjamin Bross, Gary J. Sullivan, Ye-Kui Wang, “Editors’ proposed corrections to HEVC version 1 ”, JCTVC-M0432_v3,2013.4.18-4.26 P. Silcock, K. sharman, N. Saunders, “Extension of HM7 to Support Additional Chroma Formats”, JCTVC-J0191, 2012.7.11-7.20 C. Rosewarne, M. Maeda, “AHG7: Transforms for extended chroma formats”, JCTVC-K0171, 2012.10.10-10.19

  However, the orthogonal transformation method for each divided TU is the same regardless of the distance between the TU and the PU including the TU and the adjacent neighboring image, and the orthogonal transformation for each TU is not optimized.

  This indication is made in view of such a situation, and makes it possible to improve encoding efficiency by optimizing orthogonal transform.

  The decoding device according to the first aspect of the present disclosure includes a receiving unit that receives an orthogonal transform coefficient obtained by orthogonally transforming a difference between a predicted image of an image and the image in units of transform blocks, and the received by the receiving unit A determination unit that determines a method of inverse orthogonal transform for an orthogonal transform coefficient in units of the transform block according to a distance between the transform block and the predicted image and a neighboring image adjacent to the direction of the inverse orthogonal transform; It is a decoding apparatus provided with the inverse orthogonal transformation part which carries out the inverse orthogonal transformation of the orthogonal transformation coefficient of the said conversion block unit by the system of the said inverse orthogonal transformation determined by the determination part.

  The decoding method according to the first aspect of the present disclosure corresponds to the decoding device according to the first aspect of the present disclosure.

  In the first aspect of the present disclosure, an orthogonal transform coefficient obtained by orthogonally transforming a difference between a predicted image of the image and the image in units of transform blocks is received, and an inverse orthogonal transform scheme for the orthogonal transform coefficient is: In the transform block unit, the transform block unit is determined according to the distance between the transform block and the predicted image and a neighboring image adjacent in the direction of the inverse orthogonal transform. Are orthogonally transformed.

  The encoding device according to the second aspect of the present disclosure provides an orthogonal transform method when performing orthogonal transform on a difference between a predicted image of an image and the image on a transform block basis, the transform block on the transform block basis, A determination unit that determines according to a distance between a predicted image and a neighboring image that is adjacent in the orthogonal transform direction, and the orthogonal transform of the difference in units of the transform block is performed using the orthogonal transform method determined by the determination unit. An encoding device includes an orthogonal transform unit.

  The encoding method according to the second aspect of the present disclosure corresponds to the encoding device according to the second aspect of the present disclosure.

  In the second aspect of the present disclosure, a method of orthogonal transformation when orthogonally transforming a difference between a predicted image of an image and the image in units of transform blocks is the transform block, the predicted image, and the transform block in units of transform blocks. It is determined according to the distance from the neighboring image adjacent to the direction of the orthogonal transform, and the difference of the transform block unit is orthogonally transformed by the determined orthogonal transform method.

  The decoding device according to the first aspect and the encoding device according to the second aspect can be realized by causing a computer to execute a program.

  In order to realize the decoding device of the first aspect and the encoding device of the second aspect, a program to be executed by a computer is transmitted through a transmission medium or recorded on a recording medium, Can be provided.

  The decoding device of the first aspect and the encoding device of the second aspect may be independent devices or may be internal blocks constituting one device.

  According to the first aspect of the present disclosure, decoding can be performed. Also, according to the first aspect of the present disclosure, it is possible to decode an encoded stream with improved encoding efficiency by optimizing orthogonal transform.

  According to the second aspect of the present disclosure, encoding can be performed. Also, according to the second aspect of the present disclosure, encoding efficiency can be improved by optimizing orthogonal transform.

  Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a block diagram which shows the structural example of one Embodiment of the encoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the encoding part of FIG. It is a block diagram which shows the structural example of the orthogonal transformation part of FIG. It is a figure explaining the relationship between the size of a color difference signal format, PU of a luminance signal, and a color difference signal. It is a figure explaining the determination method of the system of orthogonal transformation. It is a block diagram which shows the structural example of the inverse orthogonal transformation part of FIG. It is a figure explaining CU. It is a figure explaining intra prediction mode. It is a flowchart explaining a stream production | generation process. It is a flowchart explaining the detail of the encoding process of FIG. It is a flowchart explaining the detail of the encoding process of FIG. It is a flowchart explaining the detail of an intra color difference setting process. It is a block diagram which shows the structural example of one Embodiment of the decoding apparatus to which this indication is applied. It is a block diagram which shows the structural example of the decoding part of FIG. It is a flowchart explaining the image generation process of the decoding apparatus of FIG. It is a flowchart explaining the detail of the decoding process of FIG. It is a figure which shows the example of the other division | segmentation method of TU. It is a figure which shows the other example of TU. It is a block diagram which shows the structural example of the hardware of a computer. It is a figure which shows the example of a multiview image encoding system. It is a figure which shows the structural example of the multiview image coding apparatus to which this indication is applied. It is a figure which shows the structural example of the multiview image decoding apparatus to which this indication is applied. It is a figure which shows the example of a hierarchy image coding system. It is a figure explaining the example of spatial scalable encoding. It is a figure explaining the example of temporal scalable encoding. It is a figure explaining the example of the scalable encoding of a signal noise ratio. It is a figure which shows the structural example of the hierarchy image coding apparatus to which this indication is applied. It is a figure which shows the structural example of the hierarchy image decoding apparatus to which this indication is applied. It is a figure which shows the example of schematic structure of the television apparatus to which this indication is applied. It is a figure which shows the schematic structural example of the mobile telephone to which this indication is applied. It is a figure which shows the schematic structural example of the recording / reproducing apparatus to which this indication is applied. It is a figure which shows the schematic structural example of the imaging device to which this indication is applied. It is a block diagram which shows an example of scalable encoding utilization. It is a block diagram which shows the other example of scalable encoding utilization. It is a block diagram which shows the further another example of scalable encoding utilization. 2 illustrates an example of a schematic configuration of a video set to which the present disclosure is applied. 2 illustrates an example of a schematic configuration of a video processor to which the present disclosure is applied. The other example of the schematic structure of the video processor to which this indication is applied is shown.

<First embodiment>
(Configuration example of one embodiment of encoding device)
FIG. 1 is a block diagram illustrating a configuration example of an embodiment of an encoding device to which the present disclosure is applied.

  The encoding apparatus 10 in FIG. 1 includes a setting unit 11, an encoding unit 12, and a transmission unit 13, and encodes an image by a method according to the HEVC method.

  Specifically, the setting unit 11 of the encoding device 10 sets parameter sets such as SPS (Sequence Parameter Set), PPS (Picture Parameter Set), VUI (Video Usability Information), and SEI (Supplemental Enhancement Information). The setting unit 11 supplies the set parameter set to the encoding unit 12.

  An image in units of frames is input to the encoding unit 12. The encoding unit 12 encodes the input image by a method according to the HEVC method. The encoding unit 12 generates an encoded stream from the encoded data obtained as a result of encoding and the parameter set supplied from the setting unit 11, and supplies the encoded stream to the transmission unit 13.

  The transmission unit 13 transmits the encoded stream supplied from the encoding unit 12 to a decoding device described later.

(Configuration example of encoding unit)
FIG. 2 is a block diagram illustrating a configuration example of the encoding unit 12 of FIG.

  2 includes a format determination unit 30, an A / D conversion unit 31, a screen rearrangement buffer 32, a calculation unit 33, an orthogonal transformation unit 34, a quantization unit 35, a lossless encoding unit 36, and an accumulation buffer 37. , An inverse quantization unit 38, an inverse orthogonal transform unit 39, and an addition unit 40. The encoding unit 12 includes a deblock filter 41, an adaptive offset filter 42, an adaptive loop filter 43, a frame memory 44, a switch 45, an intra prediction unit 46, a motion prediction / compensation unit 47, a predicted image selection unit 48, and a rate. A control unit 49 is included. Furthermore, the encoding unit 12 includes a determination unit 50 and a determination unit 51.

  The format determination unit 30 of the encoding unit 12 determines the color difference signal format of the frame unit image input as the encoding target. The format determination unit 30 supplies the determination result to the orthogonal transform unit 34, the lossless encoding unit 36, and the inverse orthogonal transform unit 39.

  The A / D conversion unit 31 performs A / D conversion on the frame unit image input as an encoding target. The A / D conversion unit 31 outputs an image, which is a digital signal after conversion, to the screen rearrangement buffer 32 for storage.

  The screen rearrangement buffer 32 rearranges the stored frame-by-frame images in the order of encoding according to the GOP structure. The screen rearrangement buffer 32 outputs the rearranged image to the calculation unit 33, the intra prediction unit 46, and the motion prediction / compensation unit 47.

  The calculation unit 33 performs encoding by subtracting the prediction image supplied from the prediction image selection unit 48 from the image supplied from the screen rearrangement buffer 32. The calculation unit 33 outputs the image obtained as a result to the orthogonal transform unit 34 as residual information (difference). When the predicted image is not supplied from the predicted image selection unit 48, the calculation unit 33 outputs the image read from the screen rearrangement buffer 32 as it is to the orthogonal transform unit 34 as residual information.

  Based on the PU size of the current luminance signal to be processed and the color difference signal format supplied from the format determination unit 30, the orthogonal transform unit 34 uses the method described in Non-Patent Document 3 to The PU of the color difference signal is divided into one or more TUs. Specifically, the orthogonal transform unit 34 divides the non-square PU of the current color difference signal to be processed into a plurality of square TUs. In addition, when the PU of the current color difference signal to be processed is 32 × 32 pixels, the orthogonal transform unit 34 divides the TU into four 16 × 16 pixel TUs. Furthermore, when the PU of the current color difference signal to be processed is a square PU other than 32 × 32 pixels, the orthogonal transform unit 34 sets the PU as it is as a TU. The orthogonal transform unit 34 sequentially processes the divided TUs.

  The orthogonal transform unit 34 supplies the determination unit 50 with the PU size of the current color difference signal to be processed and the position of the TU on the PU. Accordingly, the orthogonal transform unit 34 acquires a method of orthogonal transform of the color difference signal supplied from the determination unit 50. The orthogonal transform unit 34 performs orthogonal transform on the residual information of the color difference signal in the residual information from the calculation unit 33 by the acquired method in units of TUs. Examples of orthogonal transform methods include DCT (Discrete Cosine Transform) (discrete cosine transform) and DST (Discrete Sine Transform) (discrete sine transform).

  Further, the orthogonal transform unit 34 performs orthogonal transform on the residual information of the luminance signal in the residual information from the arithmetic unit 33 in accordance with the HEVC method. The orthogonal transformation unit 34 supplies the orthogonal transformation coefficient of the luminance signal and the color difference signal obtained as a result of the orthogonal transformation to the quantization unit 35.

  The quantization unit 35 performs quantization on the orthogonal transform coefficient supplied from the orthogonal transform unit 34. The quantization unit 35 supplies the quantized orthogonal transform coefficient to the lossless encoding unit 36.

  The lossless encoding unit 36 acquires the color difference signal format from the format determination unit 30. The lossless encoding unit 36 acquires information indicating the optimal intra prediction mode (hereinafter referred to as intra prediction mode information) from the intra prediction unit 46. Further, the lossless encoding unit 36 acquires information indicating the optimal inter prediction mode (hereinafter referred to as inter prediction mode information), a motion vector, information specifying a reference image, and the like from the motion prediction / compensation unit 47.

  Further, the lossless encoding unit 36 acquires offset filter information regarding the offset filter from the adaptive offset filter 42, and acquires filter coefficients from the adaptive loop filter 43.

  The lossless encoding unit 36 performs variable length encoding (for example, CAVLC (Context-Adaptive Variable Length Coding)), arithmetic encoding (for example, for the quantized orthogonal transform coefficient supplied from the quantization unit 35). , CABAC (Context-Adaptive Binary Arithmetic Coding, etc.).

  The lossless encoding unit 36 encodes intra prediction mode information or inter prediction mode information, information specifying a motion vector, and a reference image, color difference signal format, offset filter information, and filter coefficients with respect to encoding. It is losslessly encoded as information. The lossless encoding unit 36 supplies the encoding information and the orthogonal transform coefficient, which have been losslessly encoded, to the accumulation buffer 37 as encoded data and accumulates them. Note that the losslessly encoded information may be header information (slice header) of the losslessly encoded orthogonal transform coefficient.

  The accumulation buffer 37 temporarily stores the encoded data supplied from the lossless encoding unit 36. The accumulation buffer 37 supplies the stored encoded data to the transmission unit 13 as an encoded stream together with the parameter set supplied from the setting unit 11 in FIG.

  The quantized orthogonal transform coefficient output from the quantization unit 35 is also input to the inverse quantization unit 38. The inverse quantization unit 38 performs inverse quantization on the orthogonal transform coefficient quantized by the quantization unit 35 by a method corresponding to the quantization method in the quantization unit 35. The inverse quantization unit 38 supplies the orthogonal transform coefficient obtained as a result of the inverse quantization to the inverse orthogonal transform unit 39.

  Based on the PU size of the current luminance signal PU to be processed and the color difference signal format supplied from the format determination unit 30, the inverse orthogonal transform unit 39 uses the method described in Non-Patent Document 3 to The color difference signal PU is divided into one or more TUs. The inverse orthogonal transform unit 39 sequentially processes the divided TUs.

  The inverse orthogonal transform unit 39 supplies the PU size of the current color difference signal to be processed and the position of the TU on the PU to the determination unit 51. The inverse orthogonal transform unit 39 acquires an inverse orthogonal transform method corresponding to the orthogonal transform method in the orthogonal transform unit 34 supplied from the determination unit 51. The inverse orthogonal transform unit 39 performs inverse orthogonal transform on the orthogonal transform coefficients of the chrominance signal among the orthogonal transform coefficients supplied from the inverse quantization unit 38 by the acquired method in units of TUs. As a method of inverse orthogonal transform, for example, there are IDCT (Inverse Discrete Cosine Transform) and IDST (Inverse Discrete Sine Transform).

  Further, the inverse orthogonal transform unit 39 performs inverse orthogonal transform on the orthogonal transform coefficient of the luminance signal among the orthogonal transform coefficients supplied from the inverse quantization unit 38 in accordance with the HEVC scheme. The inverse orthogonal transform unit 39 supplies residual information of the luminance signal and the color difference signal obtained as a result of the inverse orthogonal transform to the addition unit 40.

  The adder 40 adds the residual information supplied from the inverse orthogonal transform unit 39 and the prediction image supplied from the prediction image selection unit 48, and performs decoding. The adder 40 supplies the decoded image to the deblock filter 41 and the frame memory 44.

  The deblocking filter 41 performs an adaptive deblocking filter process for removing block distortion on the decoded image supplied from the adding unit 40, and supplies the resulting image to the adaptive offset filter 42.

  The adaptive offset filter 42 performs an adaptive offset filter (SAO (Sample adaptive offset)) process that mainly removes ringing on the image after the adaptive deblocking filter process by the deblocking filter 41.

  Specifically, the adaptive offset filter 42 determines the type of adaptive offset filter processing for each LCU (Largest Coding Unit) which is the maximum coding unit, and obtains an offset used in the adaptive offset filter processing. The adaptive offset filter 42 performs the determined type of adaptive offset filter processing on the image after the adaptive deblocking filter processing, using the obtained offset.

  The adaptive offset filter 42 supplies the image after the adaptive offset filter processing to the adaptive loop filter 43. Further, the adaptive offset filter 42 supplies information indicating the type and offset of the adaptive offset filter processing performed to the lossless encoding unit 36 as offset filter information.

  The adaptive loop filter 43 is configured by, for example, a two-dimensional Wiener filter. The adaptive loop filter 43 performs an adaptive loop filter (ALF (Adaptive Loop Filter)) process on the image after the adaptive offset filter process supplied from the adaptive offset filter 42, for example, for each LCU.

  Specifically, the adaptive loop filter 43 is configured so that the residual of the original image that is the image output from the screen rearrangement buffer 32 and the image after the adaptive loop filter processing is minimized for each LCU. A filter coefficient used in the processing is calculated. Then, the adaptive loop filter 43 performs adaptive loop filter processing for each LCU using the calculated filter coefficient on the image after the adaptive offset filter processing.

  The adaptive loop filter 43 supplies the image after the adaptive loop filter processing to the frame memory 44. The adaptive loop filter 43 supplies the filter coefficient used for the adaptive loop filter process to the lossless encoding unit 36.

  Here, the adaptive loop filter processing is performed for each LCU, but the processing unit of the adaptive loop filter processing is not limited to the LCU. However, the processing can be efficiently performed by combining the processing units of the adaptive offset filter 42 and the adaptive loop filter 43.

  The frame memory 44 stores the image supplied from the adaptive loop filter 43 and the image supplied from the adder 40. An image adjacent to the PU among the images not subjected to the filter processing accumulated in the frame memory 44 is supplied to the intra prediction unit 46 via the switch 45 as a peripheral image. On the other hand, the filtered image stored in the frame memory 44 is output to the motion prediction / compensation unit 47 via the switch 45 as a reference image.

  The intra prediction unit 46 performs intra prediction processing of all candidate intra prediction modes using the peripheral images read from the frame memory 44 via the switch 45 in units of PUs.

  Further, the intra prediction unit 46 calculates cost function values for all candidate intra prediction modes based on the image read from the screen rearrangement buffer 32 and the predicted image generated as a result of the intra prediction process. (Details will be described later). Then, the intra prediction unit 46 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode.

  The intra prediction unit 46 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 48. The intra prediction unit 46 supplies the intra prediction mode information to the lossless encoding unit 36 when the prediction image selection unit 48 is notified of selection of a prediction image generated in the optimal intra prediction mode.

  The cost function value is also referred to as RD (Rate Distortion) cost. It is calculated based on the method of High Complexity mode or Low Complexity mode as defined by JM (Joint Model) which is reference software in the H.264 / AVC format. H. Reference software in the H.264 / AVC format is published at http://iphome.hhi.de/suehring/tml/index.htm.

  Specifically, when the High Complexity mode is adopted as the cost function value calculation method, all the candidate prediction modes are temporarily decoded until the cost function represented by the following equation (1): A value is calculated for each prediction mode.

  D is a difference (distortion) between the original image and the decoded image, R is a generated code amount including up to the coefficient of orthogonal transformation, and λ is a Lagrange undetermined multiplier given as a function of the quantization parameter QP.

  On the other hand, when the Low Complexity mode is adopted as the cost function value calculation method, prediction image generation and coding information code amount calculation are performed for all candidate prediction modes. A cost function represented by Equation (2) is calculated for each prediction mode.

  D is the difference (distortion) between the original image and the predicted image, Header_Bit is the code amount of the encoding information, and QPtoQuant is a function given as a function of the quantization parameter QP.

  In the Low Complexity mode, it is only necessary to generate a prediction image for all prediction modes, and it is not necessary to generate a decoded image.

  The motion prediction / compensation unit 47 performs motion prediction / compensation processing in all inter prediction modes that are candidates in PU units. Specifically, the motion prediction / compensation unit 47 selects all candidate inter prediction modes based on the image supplied from the screen rearrangement buffer 32 and the reference image read from the frame memory 44 via the switch 45. Are detected in units of PUs. Then, the motion prediction / compensation unit 47 performs compensation processing on the reference image for each PU based on the motion vector, and generates a predicted image.

  At this time, the motion prediction / compensation unit 47 calculates the cost function value for all candidate inter prediction modes based on the image and the predicted image supplied from the screen rearrangement buffer 32, and the cost function value. Is determined to be the optimal inter prediction mode. Then, the motion prediction / compensation unit 47 supplies the cost function value of the optimal inter prediction mode and the corresponding prediction image to the prediction image selection unit 48. The motion prediction / compensation unit 47, when notified of the selection of the predicted image generated in the optimal inter prediction mode from the predicted image selection unit 48, specifies the inter prediction mode information, the corresponding motion vector, and the reference image. Are output to the lossless encoding unit 36.

  Based on the cost function values supplied from the intra prediction unit 46 and the motion prediction / compensation unit 47, the predicted image selection unit 48 has a smaller corresponding cost function value of the optimal intra prediction mode and the optimal inter prediction mode. Are determined as the optimum prediction mode. Then, the predicted image selection unit 48 supplies the predicted image in the optimal prediction mode to the calculation unit 33 and the addition unit 40. Further, the predicted image selection unit 48 notifies the intra prediction unit 46 or the motion prediction / compensation unit 47 of selection of the predicted image in the optimal prediction mode.

  The rate control unit 49 controls the quantization operation rate of the quantization unit 35 based on the encoded data stored in the storage buffer 37 so that overflow or underflow does not occur.

  The determination unit 50 is orthogonal to the PU of the color difference signal in units of TU (transform block) based on the PU size of the current color difference signal to be processed supplied from the orthogonal transformation unit 34 and the position of the TU on the PU. The distance between the neighboring image adjacent to the transformation direction and the TU is calculated. The determination unit 50 determines the method of orthogonal transformation of the color difference signal as DCT or DST in units of TUs according to the calculated distance. The determination unit 50 supplies the determined orthogonal transformation method to the orthogonal transformation unit 34.

  The determination unit 51 calculates the distance between the peripheral image of the color difference signal PU and the TU based on the PU size of the current color difference signal to be processed supplied from the inverse orthogonal transform unit 39 and the position of the TU on the PU. To do. The determination unit 51 determines the inverse orthogonal transformation method of the color difference signal as IDCT or IDST corresponding to the orthogonal transformation method determined by the determination unit 50 according to the calculated distance. The determination unit 51 supplies the determined inverse orthogonal transform method to the inverse orthogonal transform unit 39.

(Configuration example of orthogonal transform unit)
FIG. 3 is a block diagram illustrating a configuration example of the orthogonal transform unit 34 of FIG.

  As shown in FIG. 3, the orthogonal transform unit 34 includes a setting unit 61 and a matrix calculation unit 62.

  When the optimum intra prediction mode is selected as the optimum prediction mode, the setting unit 61 of the orthogonal transform unit 34 sets the orthogonal transformation method for the current color difference signal as follows.

  That is, the setting unit 61 determines the PU size of the current color difference signal to be processed based on the PU size of the current luminance signal to be processed and the color difference signal format supplied from the format determination unit 30. The setting unit 61 divides the PU into one or more TUs by the method described in Non-Patent Document 3 based on the size of the PU of the current color difference signal to be processed. The setting unit 61 sequentially processes the divided TUs.

  The setting unit 61 supplies the PU size of the current color difference signal to be processed and the position of the TU on the PU to the determination unit 50. Thereby, the setting unit 61 acquires the orthogonal transform method from the determination unit 50. The setting unit 61 sets the acquired orthogonal transformation method as the orthogonal transformation method for the current color difference signal.

  In addition, the setting unit 61 sets the orthogonal transform method for the current luminance signal in accordance with HEVC when the optimal intra prediction mode is selected as the optimal prediction mode. On the other hand, when the optimum inter prediction mode is selected as the optimum prediction mode, the setting unit 61 sets the orthogonal transformation method for the current luminance signal and color difference signal to DCT. The setting unit 61 supplies the matrix calculation unit 62 with the orthogonal transformation method for the current luminance signal and color difference signal and the residual information supplied from the calculation unit 33.

  The matrix calculation unit 62 orthogonally transforms the residual information for each of the luminance signal and the color difference signal using the orthogonal transformation matrix of the current orthogonal transformation method supplied from the setting unit 61.

であり、右半分は、

である。 When TU is 32 × 32 pixels, the left half of the DCT orthogonal transformation matrix is

And the right half is

It is.

  Also, the DCT orthogonal transformation matrix when the TU is 4 × 4 pixels, 8 × 8 pixels, and 16 × 16 pixels, respectively, is the DCT orthogonal transformation matrix when the TU is 32 × 32 pixels. It is obtained by thinning out to 8,1 / 4,1 / 2. Therefore, the matrix calculation unit 62 only needs to provide a calculation unit common to all sizes of TUs, and does not need to provide a calculation unit for each TU size.

  On the other hand, the DST orthogonal transformation matrix H when the TU is 4 × 4 pixels is expressed by the following equation (3).

  The matrix operation unit 62 supplies the orthogonal transform coefficient obtained as a result of the orthogonal transform to the quantization unit 35.

(Explanation of relationship between color difference signal format, luminance signal and PU size of color difference signal)
FIG. 4 is a diagram for explaining the relationship between the color difference signal format, the luminance signal, and the PU size of the color difference signal.

  In the HEVC system, orthogonal transformation of 4 × 4 pixels, 8 × 8 pixels, 16 × 16 pixels, and 32 × 32 pixels is possible.

  As shown in FIG. 4, when the color difference signal format is 4: 2: 0, the size of the color difference signal (Chroma) PU in the horizontal direction and the vertical direction is 1 of the PU size of the luminance signal (Luma), respectively. / 2 times. Specifically, when the PU size of the luminance signal is 8 × 8 pixels, 16 × 16 pixels, and 32 × 32 pixels, the PU sizes of the color difference signals are 4 × 4 pixels, 8 × 8 pixels, and 16 × 16 pixels. However, when the PU size of the luminance signal is 4 × 4 pixels, the PU size of the color difference signal is 4 × 4 pixels, which is the minimum size that can be orthogonally transformed.

  Also, when the color difference signal format is 4: 2: 2, the vertical size of the PU of the color difference signal is the same as the vertical size of the PU of the luminance signal, and the horizontal size of the PU of the color difference signal is The luminance signal is half the horizontal size of the PU. Specifically, when the PU size of the luminance signal is 8 × 8 pixels, 16 × 16 pixels, and 32 × 32 pixels, the PU sizes of the color difference signals are 4 × 8 pixels, 8 × 16 pixels, and 16 × 32 pixels. However, when the PU size of the luminance signal is 4 × 4 pixels, the PU size of the color difference signal is 4 × 4 pixels, which is the minimum size that can be orthogonally transformed.

  Further, when the color difference signal format is 4: 4: 4, the horizontal and vertical sizes of the color difference signal PU are the same as the PU size of the luminance signal, respectively. Specifically, when the PU size of the luminance signal is 4 × 4 pixels, 8 × 8 pixels, 16 × 16 pixels, and 32 × 32 pixels, the PU size of the color difference signal is 4 × 4 pixels, respectively. 8 × 8 pixels, 16 × 16 pixels, and 32 × 32 pixels.

  The setting unit 61 determines the PU size of the current color difference signal to be processed from the PU size and color difference signal format of the current luminance signal to be processed according to the table of FIG. For example, when the current processing target luminance signal PU size is 8 × 8 pixels and the color difference signal format is 4: 2: 2, the setting unit 61 sets the current processing target color difference signal PU size. Is determined to be 4 × 8 pixels.

(Explanation of orthogonal transform method judgment method)
FIG. 5 is a diagram illustrating a method for determining an orthogonal transform method.

  In the example of FIG. 5, as shown in FIG. 5A, the size of the PU 71 of the current luminance signal to be processed is 8 × 8 pixels, and the color difference signal format is 4: 2: 2.

  In this case, as shown in FIG. 5B, the size of the PU 72 of the current luminance signal to be processed is 4 × 8 pixels. Therefore, the setting unit 61 divides the PU 72 into 4 × 4 pixel TUs 73 and TUs 74 and sequentially sets them as processing targets.

  The TU 73 is in contact with the peripheral image 72A adjacent to the PU 72 in the vertical direction, which is used when the PU 72 is intra-predicted, and the vertical distance between the TU 73 and the peripheral image 72A is zero. Further, the TU 73 is also in contact with the peripheral image 72B adjacent to the PU 72 in the horizontal direction, which is used in the intra prediction of the PU 72, and the horizontal distance between the TU 73 and the peripheral image 72B is zero. Therefore, the determination unit 50 determines that the method of orthogonal transformation of the TU 73 in the horizontal direction and the vertical direction is DST.

  In other words, in a PU with a short distance from the surrounding image, the residual information at the time of intra prediction becomes smaller as the distance to the surrounding image becomes smaller and the waveform becomes closer to a sine waveform, so that DST is optimal as a method of orthogonal transformation. Therefore, in the encoding unit 12, for example, when the TU is 4 × 4 pixels and is in contact with the peripheral image, DST is selected as the orthogonal transformation method in the adjacent direction of the TU, and in other cases, the orthogonal transformation is performed. DCT is selected as the method.

  As a result, the TU orthogonal transform method at the time of intra prediction is optimized, and the coding efficiency is improved. Further, since the matrix calculation unit 62 does not need to provide a DST calculation unit when the TU size is other than 4 × 4 pixels, the scale of the matrix calculation unit 62 can be reduced.

  The TU 74 is in contact with the peripheral image 72B, but is not in contact with the peripheral image 72A. Therefore, the determination unit 50 determines the orthogonal transformation method of the horizontal TU 74 that is the adjacent direction of the peripheral image 72B and the TU 74 as DST, but determines the orthogonal transformation method of the vertical TU 74 as DCT.

(Configuration example of inverse orthogonal transform unit)
FIG. 6 is a block diagram illustrating a configuration example of the inverse orthogonal transform unit 39 in FIG.

  The inverse orthogonal transform unit 39 in FIG. 6 includes a setting unit 81 and a matrix calculation unit 82.

  When the optimum intra prediction mode is selected as the optimum prediction mode, the setting unit 81 of the inverse orthogonal transform unit 39 sets the inverse orthogonal transform method for the current color difference signal as follows.

  That is, the setting unit 81, based on the PU size of the current luminance signal to be processed and the color difference signal format supplied from the format determination unit 30, similarly to the setting unit 61, sets the current color difference signal to be processed. Divide the PU into one or more TUs. The setting unit 81 sequentially processes the divided TUs. The setting unit 81 supplies the determination unit 51 with the PU size of the current color difference signal to be processed and the position of the TU on the PU. Thereby, the setting unit 81 acquires from the determination unit 51 the inverse orthogonal transform method corresponding to the orthogonal transform method in the orthogonal transform unit 34. The setting unit 81 sets the acquired inverse orthogonal transform method to the inverse orthogonal transform method for the current color difference signal.

  The setting unit 81 sets the inverse orthogonal transform method for the current luminance signal in accordance with HEVC when the optimal intra prediction mode is selected as the optimal prediction mode. On the other hand, when the optimal inter prediction mode is selected as the optimal prediction mode, the setting unit 81 sets the inverse orthogonal transform method for the current luminance signal and color difference signal to IDCT. The setting unit 81 supplies the matrix operation unit 82 with the inverse orthogonal transform method for the current luminance signal and color difference signal and the orthogonal transform coefficient supplied from the inverse quantization unit 38.

  The matrix calculation unit 82 performs inverse orthogonal transformation of the orthogonal transformation coefficient for each of the luminance signal and the color difference signal using the inverse orthogonal transformation matrix of the current inverse orthogonal transformation method supplied from the setting unit 81. The matrix calculation unit 82 supplies residual information obtained as a result of the inverse orthogonal transform to the addition unit 40.

(Description of coding unit)
FIG. 7 is a diagram for explaining Coding UNIT (CU), which is a coding unit in the HEVC scheme.

  Since the HEVC system also targets images with large image frames such as UHD (Ultra High Definition) of 4000 × 2000 pixels, it is not optimal to fix the encoding unit size to 16 × 16 pixels. . Therefore, in the HEVC scheme, CU is defined as a coding unit.

  The CU plays the same role as the macroblock in the AVC method. Specifically, the CU is divided into PUs or TUs.

  However, the size of the CU is a square represented by a power-of-two pixel that is variable for each sequence. Specifically, the CU divides the LCU, which is the CU of the maximum size, into two in the horizontal direction and the vertical direction an arbitrary number of times so as not to be smaller than the SCU (Smallest Coding Unit) which is the CU of the minimum size. Is set by That is, the size of an arbitrary hierarchy when the LCU is hierarchized so that the size of the upper hierarchy becomes 1/4 of the size of the lower hierarchy until the SCU becomes the SCU is the size of the CU.

  For example, in FIG. 7, the LCU size is 128 and the SCU size is 8. Accordingly, the hierarchical depth (Depth) of the LCU is 0 to 4, and the hierarchical depth number is 5. That is, the number of divisions corresponding to the CU is one of 0 to 4.

  Information specifying the size of the LCU and SCU is included in the SPS. Also, the number of divisions corresponding to the CU is specified by split_flag indicating whether or not to further divide each layer. Details of the CU are described in Non-Patent Document 1.

  The size of the TU can be specified using split_transform_flag, similar to the split_flag of the CU. The maximum number of TU divisions at the time of inter prediction and intra prediction is specified by SPS as max_transform_hierarchy_depth_inter and max_transform_hierarchy_depth_intra, respectively.

  Further, in this specification, a CTU (Coding Tree Unit) is a unit that includes a CTB (Coding Tree Block) of an LCU and parameters when processing is performed on the LCU base (level). Further, it is assumed that a CU constituting a CTU is a unit including a CB (Coding Block) and a parameter for processing on the CU base (level).

(Description of intra prediction mode)
FIG. 8 is a diagram illustrating an intra prediction mode in the HEVC scheme.

  In FIG. 8, circles represent pixels.

  As shown in FIG. 8A, for example, when the size of the PU 91 of the luminance signal is 8 × 8 pixels, the intra prediction mode of the luminance signal of the AVC method is as the direction of the pixel to be the prediction pixel with respect to the prediction target pixel 92. There are an intra prediction mode indicating eight directions and an intra prediction mode in which the DC component of the surrounding image is the pixel value of the prediction pixel.

  Note that the pixel that is the predicted pixel is any one of the peripheral image 91A that is adjacent to the PU 91 in the vertical direction and the peripheral image 91B that is adjacent to the horizontal direction. In addition, the PU size of the luminance signal at the time of intra prediction of the AVC method is 4 × 4 pixels, 8 × 8 pixels, or 16 × 16 pixels. In the AVC method, the color difference signal intra prediction mode is set independently of the luminance signal for each macroblock.

  On the other hand, as shown in FIG. 8B, for example, when the size of the PU 91 of the luminance signal is 8 × 8 pixels, the intra prediction mode of the luminance signal of the HEVC scheme is the prediction pixel for the prediction target pixel 92 and There are an intra prediction mode indicating 32 directions as the direction of the pixel to be performed and an intra prediction mode in which the DC component of the surrounding image is the pixel value of the prediction pixel.

  Note that the pixel that is the predicted pixel is one of the peripheral image 91A and the peripheral image 91B. In addition, the PU size of the luminance signal at the time of HEVC intra prediction is 4 × 4 pixels, 8 × 8 pixels, 16 × 16 pixels, 32 × 32 pixels, or 64 × 64 pixels.

  As described above, since the intra prediction mode of the luminance signal of the HEVC method is larger than the intra prediction mode of the luminance signal of the AVC method, the accuracy of the predicted image at the time of the intra prediction of the HEVC method is higher than that of the AVC method. . The same applies to the color difference signal.

(Description of processing of encoding device)
FIG. 9 is a flowchart for explaining stream generation processing of the encoding device 10 of FIG.

  In step S11 of FIG. 9, the setting unit 11 of the encoding device 10 sets a parameter set. The setting unit 11 supplies the set parameter set to the encoding unit 12.

  In step S <b> 12, the encoding unit 12 performs an encoding process of encoding an image in units of frames input from the outside by a method according to the HEVC method. Details of the encoding process will be described with reference to FIGS. 10 and 11 described later.

  In step S <b> 13, the accumulation buffer 37 (FIG. 2) of the encoding unit 12 generates an encoded stream from the parameter set supplied from the setting unit 11 and the stored encoded data, and supplies the encoded stream to the transmission unit 13.

  In step S14, the transmission unit 13 transmits the encoded stream supplied from the setting unit 11 to a decoding device to be described later, and ends the process.

  10 and 11 are flowcharts illustrating details of the encoding process in step S12 of FIG.

  In step S30 of FIG. 10, the format determination unit 30 (FIG. 2) of the encoding unit 12 determines the color difference signal format of the frame unit image input as an encoding target. The format determination unit 30 supplies the determination result to the orthogonal transform unit 34, the lossless encoding unit 36, and the inverse orthogonal transform unit 39.

  In step S31, the A / D conversion unit 31 performs A / D conversion on the frame-by-frame image input as an encoding target. The A / D conversion unit 31 outputs an image, which is a digital signal after conversion, to the screen rearrangement buffer 32 for storage.

  In step S32, the screen rearrangement buffer 32 rearranges the stored frame images in the display order in the order for encoding according to the GOP structure. The screen rearrangement buffer 32 supplies the rearranged frame-unit images to the calculation unit 33, the intra prediction unit 46, and the motion prediction / compensation unit 47.

  In step S33, the intra prediction unit 46 performs intra prediction processing in all intra prediction modes that are candidates in PU units. Further, the intra prediction unit 46 calculates cost function values for all candidate intra prediction modes based on the image read from the screen rearrangement buffer 32 and the predicted image generated as a result of the intra prediction process. Is calculated. Then, the intra prediction unit 46 determines the intra prediction mode that minimizes the cost function value as the optimal intra prediction mode. The intra prediction unit 46 supplies the predicted image generated in the optimal intra prediction mode and the corresponding cost function value to the predicted image selection unit 48.

  In addition, the motion prediction / compensation unit 47 performs motion prediction / compensation processing in all inter prediction modes that are candidates in PU units. In addition, the motion prediction / compensation unit 47 calculates cost function values for all candidate inter prediction modes based on the images supplied from the screen rearrangement buffer 32 and the predicted images, and the cost function values are calculated. The minimum inter prediction mode is determined as the optimal inter prediction mode. Then, the motion prediction / compensation unit 47 supplies the cost function value of the optimal inter prediction mode and the corresponding prediction image to the prediction image selection unit 48.

  In step S <b> 34, the predicted image selection unit 48 selects one of the optimal intra prediction mode and the optimal inter prediction mode based on the cost function values supplied from the intra prediction unit 46 and the motion prediction / compensation unit 47 by the process of step S <b> 33. The one with the smallest cost function value is determined as the optimum prediction mode. Then, the predicted image selection unit 48 supplies the predicted image in the optimal prediction mode to the calculation unit 33 and the addition unit 40.

  In step S35, the predicted image selection unit 48 determines whether or not the optimal prediction mode is the optimal inter prediction mode. When it is determined in step S35 that the optimal prediction mode is the optimal inter prediction mode, the predicted image selection unit 48 notifies the motion prediction / compensation unit 47 of the selection of the predicted image generated in the optimal inter prediction mode.

  In step S36, the motion prediction / compensation unit 47 supplies the inter prediction mode information, the motion vector, and information specifying the reference image to the lossless encoding unit 36, and the process proceeds to step S38.

  On the other hand, when it is determined in step S35 that the optimal prediction mode is not the optimal inter prediction mode, that is, when the optimal prediction mode is the optimal intra prediction mode, the predicted image selection unit 48 performs the prediction generated in the optimal intra prediction mode. The intra prediction unit 46 is notified of the image selection. In step S37, the intra prediction unit 46 supplies the intra prediction mode information to the lossless encoding unit 36, and the process proceeds to step S38.

  In step S38, the calculation unit 33 performs encoding by subtracting the predicted image supplied from the predicted image selection unit 48 from the image supplied from the screen rearrangement buffer 32. The computing unit 33 outputs the resulting image to the orthogonal transform unit 34 as residual information.

  In step S39, the encoding unit 12 performs a method setting process for setting a method of orthogonal transformation for the current luminance signal and color difference signal.

  In step S40, the matrix calculation unit 62 (FIG. 3) of the orthogonal transformation unit 34 uses the orthogonal transformation matrix of the current orthogonal transformation method supplied from the setting unit 61 for each of the luminance signal and the chrominance signal. Information is orthogonally transformed in units of TUs. The matrix operation unit 62 supplies the orthogonal transform coefficient obtained as a result to the quantization unit 35.

  In step S41, the quantization unit 35 quantizes the orthogonal transform coefficient supplied from the orthogonal transform unit 34, and supplies the quantized orthogonal transform coefficient to the lossless encoding unit 36 and the inverse quantization unit 38.

  In step S42 of FIG. 11, the inverse quantization unit 38 inversely quantizes the quantized orthogonal transform coefficient supplied from the quantization unit 35, and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 39. .

  In step S43, the encoding unit 12 performs an inverse method setting process for setting an inverse orthogonal transform method for the current luminance signal and color difference signal.

  In step S44, the matrix calculation unit 82 (FIG. 6) of the inverse orthogonal transform unit 39 uses the inverse orthogonal transform matrix of the current inverse orthogonal transform method supplied from the setting unit 81 for each of the luminance signal and the color difference signal. The inverse orthogonal transform is applied to the orthogonal transform coefficient. The matrix calculation unit 82 supplies the residual information obtained as a result to the addition unit 40.

  In step S45, the addition unit 40 adds the residual information supplied from the inverse orthogonal transform unit 39 and the prediction image supplied from the prediction image selection unit 48, and performs decoding. The adder 40 supplies the decoded image to the deblock filter 41 and the frame memory 44.

  In step S <b> 46, the deblock filter 41 performs a deblocking filter process on the decoded image supplied from the addition unit 40. The deblocking filter 41 supplies the resulting image to the adaptive offset filter 42.

  In step S <b> 47, the adaptive offset filter 42 performs adaptive offset filter processing for each LCU on the image supplied from the deblocking filter 41. The adaptive offset filter 42 supplies the resulting image to the adaptive loop filter 43. Further, the adaptive offset filter 42 supplies the offset filter information to the lossless encoding unit 36 for each LCU.

  In step S <b> 48, the adaptive loop filter 43 performs an adaptive loop filter process for each LCU on the image supplied from the adaptive offset filter 42. The adaptive loop filter 43 supplies the resulting image to the frame memory 44. The adaptive loop filter 43 also supplies the filter coefficient used in the adaptive loop filter process to the lossless encoding unit 36.

  In step S49, the frame memory 44 stores the image supplied from the adaptive loop filter 43 and the image supplied from the adder 40. An image adjacent to the PU among the images not subjected to the filter processing accumulated in the frame memory 44 is supplied to the intra prediction unit 46 via the switch 45 as a peripheral image. On the other hand, the filtered image stored in the frame memory 44 is output to the motion prediction / compensation unit 47 via the switch 45 as a reference image.

  In step S50, the lossless encoding unit 36 encodes intra-prediction mode information or inter-prediction mode information, information specifying a motion vector and a reference image, color difference signal format, offset filter information, and filter coefficients into encoding information. Lossless encoding.

  In step S51, the lossless encoding unit 36 performs lossless encoding on the quantized orthogonal transform coefficient supplied from the quantization unit 35. Then, the lossless encoding unit 36 generates encoded data from the encoding information that has been losslessly encoded in the process of step S50 and the orthogonal transform coefficient that has been losslessly encoded, and supplies the encoded data to the accumulation buffer 37.

  In step S52, the accumulation buffer 37 temporarily accumulates the encoded data supplied from the lossless encoding unit 36.

  In step S <b> 53, the rate control unit 49 controls the quantization operation rate of the quantization unit 35 based on the encoded data stored in the storage buffer 37 so that overflow or underflow does not occur. And a process returns to step S12 of FIG. 9, and progresses to step S13.

  In the encoding process of FIGS. 10 and 11, in order to simplify the description, the intra prediction process and the motion prediction / compensation process are always performed. Sometimes only.

  FIG. 12 illustrates the details of the intra color difference setting process for setting the orthogonal transform method for the current color difference signal when the optimal prediction mode is the optimal intra prediction mode in the method setting process in step S39 of FIG. It is a flowchart.

  In step S71 of FIG. 12, the setting unit 61 (FIG. 3) of the orthogonal transform unit 34 determines whether the color difference signal format supplied from the format determination unit 30 is 4: 2: 2. If it is determined in step S71 that the color difference signal format is 4: 2: 2, the process proceeds to step S72.

  In step S72, the setting unit 61 determines the size of the current color difference signal PU to be processed based on 4: 2: 2 as the color difference signal format and the size of the current luminance signal PU to be processed. To do.

  In step S73, the setting unit 61 determines whether the PU size of the current color difference signal to be processed is 4 × 8 pixels. If it is determined in step S73 that the size of the current color difference signal PU to be processed is 4 × 8 pixels, the process proceeds to step S74.

  In step S74, the setting unit 61 divides the current color difference signal PU to be processed into two 4 × 4 pixel TUs. The setting unit 61 sets TUs as processing targets in order.

  The setting unit 61 supplies 4 × 8 pixels to the determination unit 50 as the PU size of the current color difference signal to be processed. Further, the setting unit 61 supplies, for example, the coordinates in pixel units representing the position on the upper left PU of the TU as the position on the PU of the processing target TU to the determination unit 50. The subsequent steps S75 to S78 are performed for each TU to be processed.

  In step S75, the determination unit 50 calculates the horizontal and vertical distances between the peripheral image of the PU of the color difference signal and the TU to be processed based on the 4 × 8 pixels and the coordinates supplied from the setting unit 61.

  In step S76, the determination unit 50 determines whether the horizontal and vertical distances are 0, that is, whether the coordinates supplied from the setting unit 61 are (0, 0). If it is determined in step S76 that the distance between the horizontal direction and the vertical direction is 0, the process proceeds to step S77.

  In step S77, the determination unit 50 determines that the orthogonal transform method for the color difference signals in the horizontal direction and the vertical direction is DST. The determination unit 50 supplies the determined orthogonal transformation method to the setting unit 61.

  Accordingly, the setting unit 61 sets the horizontal and vertical orthogonal transformation methods for the current color difference signal to DST. Then, the setting unit 61 supplies information representing DST as a method of orthogonal transformation in the horizontal direction and the vertical direction with respect to the current color difference signal and residual information supplied from the calculation unit 33 to the matrix calculation unit 62. . Then, the process ends.

  On the other hand, when it is determined in step S76 that the distance between the horizontal direction and the vertical direction is not 0, that is, when the coordinate supplied from the setting unit 61 is (0, 2), the process proceeds to step S78.

  In step S78, the determination unit 50 determines that the orthogonal conversion method of the color difference signals in the horizontal direction is DST, and determines that the orthogonal conversion method of the color difference signals in the vertical direction is DCT. The determination unit 50 supplies the determined orthogonal transformation method to the setting unit 61.

  Thus, the setting unit 61 sets the horizontal orthogonal transformation method for the current color difference signal to DST, and sets the vertical orthogonal transformation method to DCT. Then, the setting unit 61 receives information representing DST as a horizontal orthogonal transformation method for the current color difference signal and DCT as a vertical orthogonal transformation method, and residual information supplied from the calculation unit 33. To the matrix operation unit 62. Then, the process ends.

  If it is determined in step S71 that the color difference signal format is not 4: 2: 2, or if it is determined in step S73 that the PU of the color difference signal is not 4 × 8 pixels, the process proceeds to step S79.

  In step S79, the encoding unit 12 sets the horizontal and vertical orthogonal transformation methods for the current color difference signal, for example, according to the method described in Non-Patent Document 3.

  Specifically, when it is determined in step S71 that the color difference signal format is not 4: 2: 2, the setting unit 61, based on the PU size of the current luminance signal to be processed and the color difference signal format, The PU size of the current color difference signal to be processed is determined.

  The setting unit 61 divides the PU into one or more TUs by the method described in Non-Patent Document 3 based on the size of the PU of the current color difference signal to be processed. The setting unit 61 sequentially processes the divided TUs. The setting unit 61 supplies the PU size of the current color difference signal to be processed and the position of the TU on the PU to the determination unit 50.

  The determination unit 50 determines the size of the TU to be processed based on the PU size of the current color difference signal to be processed. When the size of the TU is 4 × 4 pixels, the determination unit 50 determines that the method of orthogonal conversion of the color difference signal in the horizontal direction and the vertical direction is DST for each position on the PU of the TU, and supplies it to the setting unit 61 To do. On the other hand, if the size of the TU is other than 4 × 4 pixels, the determination unit 50 determines that the orthogonal conversion method of the color difference signal in the horizontal direction and the vertical direction is DCT for each position on the PU of the TU, and sets the setting unit. 61 is supplied. The setting unit 61 sets the obtained horizontal and vertical orthogonal transformation methods to the horizontal and vertical orthogonal transformation methods for the current color difference signal.

  The setting unit 61 then supplies the matrix calculation unit 62 with the horizontal and vertical orthogonal transform methods for the current color difference signal and the residual information supplied from the calculation unit 33. Then, the process ends.

  In addition, although illustration is abbreviate | omitted, the reverse intra color difference which sets the method of the inverse orthogonal transformation with respect to the present color difference signal in the case where the optimal prediction mode is the optimal intra prediction mode among the reverse method setting processes of step S43 of FIG. The setting process is the same as the intra color difference setting process of FIG. 12 except that the orthogonal transform becomes an inverse orthogonal transform.

  That is, when the color difference signal format is 4: 2: 2 and the PU of the color difference signal is 4 × 8 pixels, when the above 4 × 4 pixel TU is processed, the horizontal direction with respect to the current color difference signal and The method of inverse orthogonal transform in the vertical direction is set to IDST. On the other hand, when the lower 4 × 4 pixel TU is a processing target, the horizontal inverse orthogonal transform method for the current color difference signal is IDST, and the vertical inverse orthogonal transform method is IDCT.

  As described above, the encoding device 10 determines the orthogonal transform method in units of TUs according to the distance between the TU and the neighboring image adjacent to the PU and the orthogonal transform direction, and the determined orthogonal transform method. The residual information is orthogonally transformed with. Therefore, the orthogonal transform can be optimized. As a result, encoding efficiency is improved.

(Configuration example of one embodiment of decoding device)
FIG. 13 is a block diagram illustrating a configuration example of an embodiment of a decoding device to which the present disclosure is applied, which decodes an encoded stream transmitted from the encoding device 10 of FIG.

  13 includes a receiving unit 111, an extracting unit 112, and a decoding unit 113.

  The receiving unit 111 of the decoding device 110 receives the encoded stream transmitted from the encoding device 10 of FIG.

  The extraction unit 112 extracts a parameter set and encoded data from the encoded stream supplied from the receiving unit 111 and supplies the parameter set and encoded data to the decoding unit 113.

  The decoding unit 113 decodes the encoded data supplied from the extraction unit 112 by a method according to the HEVC method. At this time, the decoding unit 113 also refers to the parameter set supplied from the extraction unit 112 as necessary. The decoding unit 113 outputs an image obtained as a result of decoding.

(Configuration example of decoding unit)
FIG. 14 is a block diagram illustrating a configuration example of the decoding unit 113 in FIG.

  14 includes an accumulation buffer 131, a lossless decoding unit 132, an inverse quantization unit 133, an inverse orthogonal transform unit 134, an addition unit 135, a deblock filter 136, an adaptive offset filter 137, an adaptive loop filter 138, and a screen. A rearrangement buffer 139 is provided. The decoding unit 113 includes a D / A conversion unit 140, a frame memory 141, a switch 142, an intra prediction unit 143, a motion compensation unit 144, a switch 145, a format determination unit 146, and a determination unit 147.

  The accumulation buffer 131 of the decoding unit 113 receives and accumulates encoded data from the extraction unit 112 of FIG. The accumulation buffer 131 supplies the accumulated encoded data to the lossless decoding unit 132.

  The lossless decoding unit 132 obtains quantized orthogonal transform coefficients and encoding information by performing lossless decoding such as variable length decoding and arithmetic decoding on the encoded data from the accumulation buffer 131. The lossless decoding unit 132 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133. Further, the lossless decoding unit 132 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 132 supplies a motion vector, inter prediction mode information, information for specifying a reference image, and the like to the motion compensation unit 144.

  Further, the lossless decoding unit 132 supplies intra prediction mode information or inter prediction mode information as encoded information to the switch 145. The lossless decoding unit 132 supplies offset filter information as encoded information to the adaptive offset filter 137. The lossless decoding unit 132 supplies filter coefficients as encoded information to the adaptive loop filter 138.

  Further, the lossless decoding unit 132 supplies the color difference signal format as the encoded information to the format determination unit 146.

  Inverse quantization unit 133, inverse orthogonal transform unit 134, addition unit 135, deblock filter 136, adaptive offset filter 137, adaptive loop filter 138, frame memory 141, switch 142, intra prediction unit 143, motion compensation unit 144, and determination 2 includes an inverse quantization unit 38, an inverse orthogonal transform unit 39, an addition unit 40, a deblock filter 41, an adaptive offset filter 42, an adaptive loop filter 43, a frame memory 44, a switch 45, an intra prediction unit 46, The same processing as that performed by the motion prediction / compensation unit 47 and the determination unit 51 is performed, whereby an image is decoded.

  Specifically, the inverse quantization unit 133 dequantizes the quantized orthogonal transform coefficient from the lossless decoding unit 132 and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 134.

  The inverse orthogonal transform unit 134 is configured in the same manner as the inverse orthogonal transform unit 39 in FIG. Based on the PU size of the current luminance signal PU to be processed and the color difference signal format supplied from the format determination unit 146, the inverse orthogonal transform unit 134 performs the current processing target by the method described in Non-Patent Document 3. The color difference signal PU is divided into one or more TUs. The inverse orthogonal transform unit 134 sequentially processes the divided TUs.

  The inverse orthogonal transform unit 134 supplies the PU size of the current color difference signal to be processed and the position of the TU on the PU to the determination unit 147. The inverse orthogonal transform unit 134 obtains the inverse orthogonal transform method corresponding to the orthogonal transform method in the orthogonal transform unit 34 of FIG. The inverse orthogonal transform unit 134 performs inverse orthogonal transform on the orthogonal transform coefficients of the color difference signal among the orthogonal transform coefficients supplied from the inverse quantization unit 133 in units of TUs using the acquired method.

  Further, the inverse orthogonal transform unit 134 performs inverse orthogonal transform on the orthogonal transform coefficient of the luminance signal among the orthogonal transform coefficients supplied from the inverse quantization unit 133 in accordance with the HEVC scheme. The inverse orthogonal transform unit 134 supplies the residual information of the luminance signal and the color difference signal obtained as a result of the inverse orthogonal transform to the addition unit 135.

  The adding unit 135 performs decoding by adding the residual information supplied from the inverse orthogonal transform unit 134 and the prediction image supplied from the switch 145. The adder 135 supplies the decoded image to the deblock filter 136 and the frame memory 141.

  The deblocking filter 136 performs an adaptive deblocking filter process on the image supplied from the adding unit 135 and supplies an image obtained as a result to the adaptive offset filter 137.

  The adaptive offset filter 137 performs, for each LCU, the type of adaptive offset filter processing represented by the offset filter information on the image after the adaptive deblocking filter processing using the offset represented by the offset filter information from the lossless decoding unit 132. Do. The adaptive offset filter 137 supplies the image after the adaptive offset filter processing to the adaptive loop filter 138.

  The adaptive loop filter 138 performs adaptive loop filter processing for each LCU on the image supplied from the adaptive offset filter 137 using the filter coefficient supplied from the lossless decoding unit 132. The adaptive loop filter 138 supplies the resulting image to the frame memory 141 and the screen rearrangement buffer 139.

  The screen rearrangement buffer 139 stores the image supplied from the adaptive loop filter 138 in units of frames. The screen rearrangement buffer 139 rearranges the stored frame-by-frame images for encoding in the original display order and supplies them to the D / A conversion unit 140.

  The D / A conversion unit 140 D / A converts the frame unit image supplied from the screen rearrangement buffer 139 and outputs the converted image.

  The frame memory 141 stores the image supplied from the adaptive loop filter 138 and the image supplied from the adding unit 135. An image adjacent to the PU among the images not subjected to the filter processing accumulated in the frame memory 141 is supplied to the intra prediction unit 143 through the switch 142 as a peripheral image. On the other hand, the filtered image stored in the frame memory 141 is supplied to the motion compensation unit 144 via the switch 142 as a reference image.

  The intra prediction unit 143 performs intra prediction processing in the optimal intra prediction mode indicated by the intra prediction mode information supplied from the lossless decoding unit 132, using the peripheral image read from the frame memory 141 via the switch 142. The intra prediction unit 143 supplies the prediction image generated as a result to the switch 145.

  The motion compensation unit 144 reads the reference image specified by the information specifying the reference image supplied from the lossless decoding unit 132 from the frame memory 141 via the switch 142. The motion compensation unit 144 performs motion compensation processing in the optimal inter prediction mode indicated by the inter prediction mode information supplied from the lossless decoding unit 132, using the motion vector and the reference image supplied from the lossless decoding unit 132. The motion compensation unit 144 supplies the predicted image generated as a result to the switch 145.

  When the intra prediction mode information is supplied from the lossless decoding unit 132, the switch 145 supplies the prediction image supplied from the intra prediction unit 143 to the addition unit 135. On the other hand, when the inter prediction mode information is supplied from the lossless decoding unit 132, the switch 145 supplies the prediction image supplied from the motion compensation unit 144 to the adding unit 135.

  The format determination unit 146 acquires the color difference signal format supplied from the lossless decoding unit 132 and supplies it to the inverse orthogonal transform unit 134.

  Based on the PU size of the current color difference signal to be processed supplied from the inverse orthogonal transform unit 134 and the position of the TU (transform block) on the PU, the determination unit 147 determines the PU of the color difference signal in units of TUs. The distance between the neighboring image adjacent to the direction of inverse orthogonal transformation and the TU is calculated. The determination unit 147 determines the inverse orthogonal transform method of the color difference signal in units of TUs as IDCT or IDST corresponding to the orthogonal transform method selected by the determination unit 50 in FIG. 2 according to the calculated distance. The determination unit 147 supplies the determined inverse orthogonal transform method to the inverse orthogonal transform unit 134.

(Description of processing of decoding device)
FIG. 15 is a flowchart illustrating the image generation processing of the decoding device 110 in FIG.

  In step S111 in FIG. 15, the reception unit 111 of the decoding device 110 receives the encoded stream transmitted from the encoding device 10 in FIG. 1 and supplies the encoded stream to the extraction unit 112.

  In step S <b> 112, the extraction unit 112 extracts encoded data and a parameter set from the encoded stream supplied from the reception unit 111 and supplies the extracted encoded data and parameter set to the decoding unit 113.

  In step S113, the decoding unit 113 performs a decoding process for decoding the encoded data supplied from the extraction unit 112 using a parameter set supplied from the extraction unit 112 according to a method according to the HEVC method. Details of this decoding process will be described with reference to FIG. Then, the process ends.

  FIG. 16 is a flowchart illustrating details of the decoding process in step S113 of FIG.

  In step S131 of FIG. 16, the accumulation buffer 131 (FIG. 14) of the decoding unit 113 receives and accumulates encoded data in units of frames from the extraction unit 112 of FIG. The accumulation buffer 131 supplies the accumulated encoded data to the lossless decoding unit 132.

  In step S132, the lossless decoding unit 132 losslessly decodes the encoded data from the accumulation buffer 131, and obtains quantized orthogonal transform coefficients and encoded information. The lossless decoding unit 132 supplies the quantized orthogonal transform coefficient to the inverse quantization unit 133. The lossless decoding unit 132 supplies the color difference signal format as the encoding information to the format determination unit 146.

  Further, the lossless decoding unit 132 supplies intra prediction mode information as encoded information to the intra prediction unit 143. The lossless decoding unit 132 supplies a motion vector, inter prediction mode information, information for specifying a reference image, and the like to the motion compensation unit 144.

  Further, the lossless decoding unit 132 supplies intra prediction mode information or inter prediction mode information as encoded information to the switch 145. The lossless decoding unit 132 supplies offset filter information as encoded information to the adaptive offset filter 137 and supplies filter coefficients to the adaptive loop filter 138.

  In step S <b> 133, the format determination unit 146 acquires the color difference signal format from the lossless decoding unit 132 and supplies it to the inverse orthogonal transform unit 134.

  In step S <b> 134, the inverse quantization unit 133 inversely quantizes the quantized orthogonal transform coefficient from the lossless decoding unit 132 and supplies the resulting orthogonal transform coefficient to the inverse orthogonal transform unit 134.

  In step S135, the motion compensation unit 144 determines whether or not the inter prediction mode information is supplied from the lossless decoding unit 132. If it is determined in step S135 that the inter prediction mode information has been supplied, the process proceeds to step S136.

  In step S136, the motion compensation unit 144 reads a reference image based on the reference image specifying information supplied from the lossless decoding unit 132, and uses the motion vector and the reference image to determine the optimal inter prediction mode indicated by the inter prediction mode information. Perform motion compensation processing. The motion compensation unit 144 supplies the predicted image generated as a result to the addition unit 135 via the switch 145, and the process proceeds to step S138.

  On the other hand, if it is determined in step S135 that the inter prediction mode information is not supplied, that is, if the intra prediction mode information is supplied to the intra prediction unit 143, the process proceeds to step S137.

  In step S137, the intra prediction unit 143 performs intra prediction processing in the intra prediction mode indicated by the intra prediction mode information, using the peripheral image read from the frame memory 141 via the switch 142. The intra prediction unit 143 supplies the prediction image generated as a result of the intra prediction process to the adding unit 135 via the switch 145, and the process proceeds to step S138.

  In step S <b> 138, the decoding unit 113 performs an inverse method setting process in the same manner as the encoding unit 12.

  In step S139, the inverse orthogonal transform unit 134 performs inverse transform on the orthogonal transform coefficient by using the inverse orthogonal transform matrix of the current inverse orthogonal transform method set by the inverse method setting process for each of the luminance signal and the color difference signal. Perform orthogonal transformation. The inverse orthogonal transform unit 134 supplies the residual information obtained as a result to the addition unit 135.

  In step S140, the addition unit 135 performs decoding by adding the residual information supplied from the inverse orthogonal transform unit 134 and the prediction image supplied from the switch 145. The adder 135 supplies the decoded image to the deblock filter 136 and the frame memory 141.

  In step S <b> 141, the deblocking filter 136 performs deblocking filtering on the image supplied from the adding unit 135 to remove block distortion. The deblocking filter 136 supplies the resulting image to the adaptive offset filter 137.

  In step S142, the adaptive offset filter 137 performs adaptive offset filter processing for each LCU on the image after the deblocking filter processing by the deblocking filter 136 based on the offset filter information supplied from the lossless decoding unit 132. . The adaptive offset filter 137 supplies the image after the adaptive offset filter processing to the adaptive loop filter 138.

  In step S143, the adaptive loop filter 138 performs adaptive loop filter processing for each LCU on the image supplied from the adaptive offset filter 137 using the filter coefficient supplied from the lossless decoding unit 132. The adaptive loop filter 138 supplies the resulting image to the frame memory 141 and the screen rearrangement buffer 139.

  In step S144, the frame memory 141 accumulates the image supplied from the adder 135 and the image supplied from the adaptive loop filter 138. An image adjacent to the PU among the images not subjected to the filter processing accumulated in the frame memory 141 is supplied to the intra prediction unit 143 through the switch 142 as a peripheral image. On the other hand, the filtered image stored in the frame memory 141 is supplied to the motion compensation unit 144 via the switch 142 as a reference image.

  In step S145, the screen rearrangement buffer 139 stores the image supplied from the adaptive loop filter 138 in units of frames, and rearranges the stored frame-by-frame images for encoding in the original display order. To the D / A converter 140.

  In step S146, the D / A conversion unit 140 performs D / A conversion on the frame-based image supplied from the screen rearrangement buffer 139 and outputs it. Then, the process returns to step S113 in FIG.

  As described above, the decoding apparatus 110 determines the inverse orthogonal transform method according to the distance between the TU and the neighboring image adjacent to the PU and the orthogonal transform direction in units of TUs, and performs the determined inverse orthogonal transform. The orthogonal transform coefficient is inversely orthogonal transformed by the method. Accordingly, it is possible to perform inverse orthogonal transformation on the orthogonal transformation coefficient by the optimized orthogonal transformation and obtain residual information. As a result, it is possible to decode the encoded stream with improved encoding efficiency by optimizing the orthogonal transform in the encoding device 10.

(Other division methods of TU)
In the above description, the PU is divided into a plurality of 4 × 4 pixel TUs only when the color difference signal format is 4: 2: 0 and the PU of the color difference signal is 4 × 8 pixels. The color difference signal PUs of other sizes in the color difference signal format may also be divided into a plurality of 4 × 4 pixel TUs.

  For example, as shown in FIG. 17, when the PU 160 of the color difference signal is 8 × 8 pixels, the PU 160 may be divided into four 4 × 4 pixel TUs 161 to 164. That is, the color difference signal format is 4: 2: 0 and the luminance signal PU is 16 × 16 pixels, or the color difference signal format is 4: 4: 4 and the luminance signal PU is 8 × 8 pixels. In some cases, the PU of the color difference signal may be divided into four 4 × 4 pixel TUs.

  In this case, since the upper left TU 161 is in contact with the peripheral image 160A adjacent to the PU 160 in the vertical direction and the peripheral image 160B adjacent to the PU 160 in the horizontal direction, the orthogonal transformation in the horizontal direction and the vertical direction of the TU 161 at the time of intra prediction is performed. The method is DST.

  On the other hand, the upper right TU 162 is in contact with the peripheral image 160A, but is not in contact with the peripheral image 160B. Therefore, the vertical orthogonal transformation method of the TU 162 at the time of intra prediction is DST, but the horizontal orthogonal transformation is performed. This method is DCT.

  Further, the lower left TU 163 is in contact with the peripheral image 160B, but is not in contact with the peripheral image 160A. Therefore, the method of horizontal orthogonal transformation of the TU 163 at the time of intra prediction is DST, but vertical orthogonal transformation is performed. This method is DCT.

  Further, since the lower right TU 164 is not in contact with both the peripheral image 160A and the peripheral image 160B, the horizontal and vertical orthogonal transformation methods of the TU 164 at the time of intra prediction are DCT.

  Although not present in the table of FIG. 4, when there are 8 × 4 pixels as the size of the PU 180 of the color difference signal as shown in FIG. 18, the PU 180 is divided into two 4 × 4 pixel TUs 181 and 182. You may do it.

  In this case, since the left TU 181 is in contact with the peripheral image 180A vertically adjacent to the PU 180 and the peripheral image 180B horizontally adjacent, the method of orthogonal transformation of the TU 181 in the vertical and horizontal directions at the time of intra prediction is as follows. DST.

  On the other hand, the TU 182 on the right side touches the peripheral image 180A, but does not touch the peripheral image 180B. Therefore, the method of orthogonal transformation in the vertical direction of the TU 182 at the time of intra prediction is DST, but the method of orthogonal transformation in the horizontal direction is DCT.

<Second Embodiment>
(Description of computer to which the present disclosure is applied)
The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer capable of executing various functions by installing various programs by installing a computer incorporated in dedicated hardware.

  FIG. 19 is a block diagram illustrating an example of a hardware configuration of a computer that executes the series of processes described above according to a program.

  In a computer, a central processing unit (CPU) 201, a read only memory (ROM) 202, and a random access memory (RAM) 203 are connected to each other by a bus 204.

  An input / output interface 205 is further connected to the bus 204. An input unit 206, an output unit 207, a storage unit 208, a communication unit 209, and a drive 210 are connected to the input / output interface 205.

  The input unit 206 includes a keyboard, a mouse, a microphone, and the like. The output unit 207 includes a display, a speaker, and the like. The storage unit 208 includes a hard disk, a nonvolatile memory, and the like. The communication unit 209 includes a network interface and the like. The drive 210 drives a removable medium 211 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

  In the computer configured as described above, the CPU 201 loads, for example, the program stored in the storage unit 208 to the RAM 203 via the input / output interface 205 and the bus 204 and executes the program. Is performed.

  The program executed by the computer (CPU 201) can be provided by being recorded on the removable medium 211 as a package medium or the like, for example. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

  In the computer, the program can be installed in the storage unit 208 via the input / output interface 205 by attaching the removable medium 211 to the drive 210. The program can be received by the communication unit 209 via a wired or wireless transmission medium and installed in the storage unit 208. In addition, the program can be installed in the ROM 202 or the storage unit 208 in advance.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

<Third Embodiment>
(Application to multi-view image coding and multi-view image decoding)
The series of processes described above can be applied to multi-view image encoding / multi-view image decoding. FIG. 20 shows an example of a multi-view image encoding method.

  As shown in FIG. 20, the multi-viewpoint image includes images of a plurality of viewpoints (views). Multiple views of this multi-viewpoint image are encoded using the base view that encodes and decodes using only the image of its own view without using the image of the other view, and the image of the other view. -It consists of a non-base view that performs decoding. For the non-base view, an image of the base view may be used, or an image of another non-base view may be used.

  When encoding / decoding a multi-view image as shown in FIG. 20, the image of each view is encoded / decoded. For the encoding / decoding of each view, the method of the first embodiment described above is used. You may make it apply. By doing so, it is possible to improve the coding efficiency by optimizing the orthogonal transform.

  Furthermore, in encoding / decoding of each view, flags and parameters used in the method of the first embodiment described above may be shared. Of course, other necessary information may be shared in encoding / decoding of each view.

  By doing in this way, transmission of redundant information can be suppressed and the amount of information to be transmitted (code amount) can be reduced (that is, reduction in encoding efficiency can be suppressed).

(Multi-view image encoding device)
FIG. 21 is a diagram illustrating a multi-view image encoding apparatus that performs the above-described multi-view image encoding. As illustrated in FIG. 21, the multi-view image encoding device 600 includes an encoding unit 601, an encoding unit 602, and a multiplexing unit 603.

  The encoding unit 601 encodes the base view image and generates a base view image encoded stream. The encoding unit 602 encodes the non-base view image and generates a non-base view image encoded stream. The multiplexing unit 603 multiplexes the base view image encoded stream generated by the encoding unit 601 and the non-base view image encoded stream generated by the encoding unit 602 to generate a multi-view image encoded stream. To do.

  The encoding device 10 (FIG. 1) can be applied to the encoding unit 601 and the encoding unit 602 of the multi-view image encoding device 600. That is, in the encoding for each view, the encoding efficiency can be improved by optimizing the orthogonal transform. Also, the encoding unit 601 and the encoding unit 602 can perform encoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, share the flags and parameters). Therefore, it is possible to suppress a reduction in encoding efficiency.

(Multi-viewpoint image decoding device)
FIG. 22 is a diagram illustrating a multi-view image decoding apparatus that performs the above-described multi-view image decoding. As illustrated in FIG. 22, the multi-view image decoding device 610 includes a demultiplexing unit 611, a decoding unit 612, and a decoding unit 613.

  The demultiplexing unit 611 demultiplexes the multi-view image encoded stream in which the base view image encoded stream and the non-base view image encoded stream are multiplexed, and the base view image encoded stream and the non-base view image The encoded stream is extracted. The decoding unit 612 decodes the base view image encoded stream extracted by the demultiplexing unit 611 to obtain a base view image. The decoding unit 613 decodes the non-base view image encoded stream extracted by the demultiplexing unit 611 to obtain a non-base view image.

  The decoding device 110 (FIG. 13) can be applied to the decoding unit 612 and the decoding unit 613 of the multi-view image decoding device 610. That is, in decoding for each view, an encoded stream with improved encoding efficiency can be decoded by optimizing orthogonal transform. In addition, the decoding unit 612 and the decoding unit 613 can perform decoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the flags and parameters can be shared). Therefore, it is possible to suppress a reduction in encoding efficiency.

<Fourth embodiment>
(Application to hierarchical image coding / hierarchical image decoding)
The series of processes described above can be applied to hierarchical image encoding / hierarchical image decoding (scalable encoding / scalable decoding). FIG. 23 shows an example of a hierarchical image encoding method.

  Hierarchical image coding (scalable coding) is a method in which image data is divided into a plurality of layers (hierarchized) so as to have a scalable function with respect to a predetermined parameter, and is encoded for each layer. Hierarchical image decoding (scalable decoding) is decoding corresponding to the hierarchical image encoding.

  As shown in FIG. 23, in image hierarchization, one image is divided into a plurality of images (layers) based on a predetermined parameter having a scalable function. That is, the hierarchized image (hierarchical image) includes images of a plurality of hierarchies (layers) having different predetermined parameter values. A plurality of layers of this hierarchical image are encoded / decoded using only the image of the own layer without using the image of the other layer, and encoded / decoded using the image of the other layer. It consists of a non-base layer (also called enhancement layer) that performs decoding. As the non-base layer, an image of the base layer may be used, or an image of another non-base layer may be used.

  In general, the non-base layer is composed of difference image data (difference data) between its own image and an image of another layer so that redundancy is reduced. For example, when one image is divided into two layers of a base layer and a non-base layer (also referred to as an enhancement layer), an image with lower quality than the original image can be obtained using only the base layer data. By synthesizing the base layer data, an original image (that is, a high-quality image) can be obtained.

  By hierarchizing images in this way, it is possible to easily obtain images of various qualities depending on the situation. For example, to a terminal with low processing capability, such as a mobile phone, image compression information of only the base layer is transmitted, and a moving image with low spatiotemporal resolution or poor image quality is reproduced. For terminals with high processing capabilities, such as televisions and personal computers, in addition to the base layer, the image compression information of the enhancement layer is transmitted and the spatial time resolution is high, or Image compression information corresponding to the capabilities of the terminal and the network can be transmitted from the server without performing transcoding processing, such as playing a moving image with high image quality.

  In the case of encoding / decoding a hierarchical image as in the example of FIG. 23, the image of each layer is encoded / decoded. For the encoding / decoding of each layer, the method of the first embodiment described above is used. May be applied. By doing so, it is possible to improve the coding efficiency by optimizing the orthogonal transform.

  Furthermore, in encoding / decoding of each layer, the flags and parameters used in the method of the first embodiment described above may be shared. Of course, other necessary information may be shared in encoding / decoding of each layer.

  By doing in this way, transmission of redundant information can be suppressed and the amount of information to be transmitted (code amount) can be reduced (that is, reduction in encoding efficiency can be suppressed).

(Scalable parameters)
In such hierarchical image encoding / hierarchical image decoding (scalable encoding / scalable decoding), parameters having a scalable function are arbitrary. For example, the spatial resolution as shown in FIG. 24 may be used as the parameter (spatial scalability). In the case of this spatial scalability, the resolution of the image is different for each layer. That is, in this case, as shown in FIG. 24, each picture has two layers of a base layer having a spatially lower resolution than the original image and an enhancement layer from which the original spatial resolution can be obtained by combining with the base layer. Is layered. Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

  In addition, for example, temporal resolution as shown in FIG. 25 may be applied as a parameter for providing such scalability (temporal scalability). In the case of this temporal scalability, the frame rate is different for each layer. That is, in this case, as shown in FIG. 25, each picture is divided into two layers of a base layer having a lower frame rate than the original moving image and an enhancement layer from which the original frame rate can be obtained by combining with the base layer. Layered. Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

  Furthermore, for example, a signal-to-noise ratio (SNR) may be applied as a parameter that provides such scalability (SNR scalability). In the case of this SNR scalability (SNR scalability), the SN ratio is different for each layer. That is, in this case, as shown in FIG. 26, each picture is hierarchized into two layers: a base layer having a lower SNR than the original image, and an enhancement layer from which the original SNR is obtained by combining with the base layer. The Of course, this number of hierarchies is an example, and the number of hierarchies can be hierarchized.

  Of course, parameters other than the above-described example may be used for providing the scalable property. For example, bit depth can also be used as a parameter for providing scalability (bit-depth scalability). In the case of this bit depth scalability (bit-depth scalability), the bit depth differs for each layer. In this case, for example, the base layer is composed of an 8-bit image, and an enhancement layer is added to the 8-bit image so that a 10-bit image can be obtained.

  Moreover, a chroma format can also be used as a parameter which gives scalable property (chroma scalability). In the case of this chroma scalability, the chroma format is different for each layer. In this case, for example, the base layer is composed of a component image of 4: 2: 0 format, and an enhancement layer is added thereto to obtain a component image of 4: 2: 2 format. Can be.

(Hierarchical image encoding device)
FIG. 27 is a diagram illustrating a hierarchical image encoding apparatus that performs the above-described hierarchical image encoding. As illustrated in FIG. 27, the hierarchical image encoding device 620 includes an encoding unit 621, an encoding unit 622, and a multiplexing unit 623.

  The encoding unit 621 encodes the base layer image and generates a base layer image encoded stream. The encoding unit 622 encodes the non-base layer image and generates a non-base layer image encoded stream. The multiplexing unit 623 multiplexes the base layer image encoded stream generated by the encoding unit 621 and the non-base layer image encoded stream generated by the encoding unit 622 to generate a hierarchical image encoded stream. .

  The encoding device 10 (FIG. 1) can be applied to the encoding unit 621 and the encoding unit 622 of the hierarchical image encoding device 620. That is, in the encoding for each layer, the encoding efficiency can be improved by optimizing the orthogonal transform. Also, the encoding unit 621 and the encoding unit 622 can perform control of intra prediction filter processing using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the intra prediction processing). Therefore, it is possible to share a flag and a parameter), and it is possible to suppress a reduction in encoding efficiency.

(Hierarchical image decoding device)
FIG. 28 is a diagram illustrating a hierarchical image decoding apparatus that performs the hierarchical image decoding described above. As illustrated in FIG. 28, the hierarchical image decoding device 630 includes a demultiplexing unit 631, a decoding unit 632, and a decoding unit 633.

  The demultiplexing unit 631 demultiplexes the hierarchical image encoded stream in which the base layer image encoded stream and the non-base layer image encoded stream are multiplexed, and the base layer image encoded stream and the non-base layer image code Stream. The decoding unit 632 decodes the base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a base layer image. The decoding unit 633 decodes the non-base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a non-base layer image.

  The decoding device 110 (FIG. 13) can be applied to the decoding unit 632 and the decoding unit 633 of the hierarchical image decoding device 630. That is, in decoding for each layer, an encoded stream with improved encoding efficiency can be decoded by optimizing orthogonal transformation. In addition, the decoding unit 612 and the decoding unit 613 can perform decoding using the same flags and parameters (for example, syntax elements related to processing between images) (that is, the flags and parameters can be shared). Therefore, it is possible to suppress a reduction in encoding efficiency.

<Fifth embodiment>
(Example configuration of television device)
FIG. 29 illustrates a schematic configuration of a television device to which the present disclosure is applied. The television apparatus 900 includes an antenna 901, a tuner 902, a demultiplexer 903, a decoder 904, a video signal processing unit 905, a display unit 906, an audio signal processing unit 907, a speaker 908, and an external interface unit 909. Furthermore, the television apparatus 900 includes a control unit 910, a user interface unit 911, and the like.

  The tuner 902 selects and demodulates a desired channel from the broadcast wave signal received by the antenna 901, and outputs the obtained encoded bit stream to the demultiplexer 903.

  The demultiplexer 903 extracts video and audio packets of the program to be viewed from the encoded bit stream, and outputs the extracted packet data to the decoder 904. Further, the demultiplexer 903 supplies a packet of data such as EPG (Electronic Program Guide) to the control unit 910. If scrambling is being performed, descrambling is performed by a demultiplexer or the like.

  The decoder 904 performs a packet decoding process, and outputs video data generated by the decoding process to the video signal processing unit 905 and audio data to the audio signal processing unit 907.

  The video signal processing unit 905 performs noise removal, video processing according to user settings, and the like on the video data. The video signal processing unit 905 generates video data of a program to be displayed on the display unit 906, image data by processing based on an application supplied via a network, and the like. The video signal processing unit 905 generates video data for displaying a menu screen for selecting an item and the like, and superimposes the video data on the video data of the program. The video signal processing unit 905 generates a drive signal based on the video data generated in this way, and drives the display unit 906.

  The display unit 906 drives a display device (for example, a liquid crystal display element or the like) based on a drive signal from the video signal processing unit 905 to display a program video or the like.

  The audio signal processing unit 907 performs predetermined processing such as noise removal on the audio data, performs D / A conversion processing and amplification processing on the audio data after processing, and outputs the audio data to the speaker 908.

  The external interface unit 909 is an interface for connecting to an external device or a network, and performs data transmission / reception such as video data and audio data.

  A user interface unit 911 is connected to the control unit 910. The user interface unit 911 includes an operation switch, a remote control signal receiving unit, and the like, and supplies an operation signal corresponding to a user operation to the control unit 910.

  The control unit 910 is configured using a CPU (Central Processing Unit), a memory, and the like. The memory stores a program executed by the CPU, various data necessary for the CPU to perform processing, EPG data, data acquired via a network, and the like. The program stored in the memory is read and executed by the CPU at a predetermined timing such as when the television device 900 is activated. The CPU executes each program to control each unit so that the television device 900 operates in accordance with the user operation.

  Note that the television device 900 is provided with a bus 912 for connecting the tuner 902, the demultiplexer 903, the video signal processing unit 905, the audio signal processing unit 907, the external interface unit 909, and the control unit 910.

  In the television device configured as described above, the decoder 904 is provided with the function of the decoding device (decoding method) of the present application. For this reason, it is possible to decode an encoded stream with improved encoding efficiency by optimizing the orthogonal transform.

<Sixth embodiment>
(Configuration example of mobile phone)
FIG. 30 illustrates a schematic configuration of a mobile phone to which the present disclosure is applied. The cellular phone 920 includes a communication unit 922, an audio codec 923, a camera unit 926, an image processing unit 927, a demultiplexing unit 928, a recording / reproducing unit 929, a display unit 930, and a control unit 931. These are connected to each other via a bus 933.

  An antenna 921 is connected to the communication unit 922, and a speaker 924 and a microphone 925 are connected to the audio codec 923. Further, an operation unit 932 is connected to the control unit 931.

  The cellular phone 920 performs various operations such as transmission / reception of voice signals, transmission / reception of e-mail and image data, image shooting, and data recording in various modes such as a voice call mode and a data communication mode.

  In the voice call mode, the voice signal generated by the microphone 925 is converted into voice data and compressed by the voice codec 923 and supplied to the communication unit 922. The communication unit 922 performs audio data modulation processing, frequency conversion processing, and the like to generate a transmission signal. The communication unit 922 supplies a transmission signal to the antenna 921 and transmits it to a base station (not shown). In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and supplies the obtained audio data to the audio codec 923. The audio codec 923 performs data expansion of the audio data and conversion to an analog audio signal and outputs the result to the speaker 924.

  In addition, when mail transmission is performed in the data communication mode, the control unit 931 accepts character data input by operating the operation unit 932 and displays the input characters on the display unit 930. In addition, the control unit 931 generates mail data based on a user instruction or the like in the operation unit 932 and supplies the mail data to the communication unit 922. The communication unit 922 performs mail data modulation processing, frequency conversion processing, and the like, and transmits the obtained transmission signal from the antenna 921. In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and restores mail data. This mail data is supplied to the display unit 930 to display the mail contents.

  Note that the cellular phone 920 can also store the received mail data in a storage medium by the recording / playback unit 929. The storage medium is any rewritable storage medium. For example, the storage medium is a removable memory such as a semiconductor memory such as a RAM or a built-in flash memory, a hard disk, a magnetic disk, a magneto-optical disk, an optical disk, a USB (Universal Serial Bus) memory, or a memory card.

  When transmitting image data in the data communication mode, the image data generated by the camera unit 926 is supplied to the image processing unit 927. The image processing unit 927 performs encoding processing of image data and generates encoded data.

  The demultiplexing unit 928 multiplexes the encoded data generated by the image processing unit 927 and the audio data supplied from the audio codec 923 by a predetermined method, and supplies the multiplexed data to the communication unit 922. The communication unit 922 performs modulation processing and frequency conversion processing of multiplexed data, and transmits the obtained transmission signal from the antenna 921. In addition, the communication unit 922 performs amplification, frequency conversion processing, demodulation processing, and the like of the reception signal received by the antenna 921, and restores multiplexed data. This multiplexed data is supplied to the demultiplexing unit 928. The demultiplexing unit 928 performs demultiplexing of the multiplexed data, and supplies the encoded data to the image processing unit 927 and the audio data to the audio codec 923. The image processing unit 927 performs a decoding process on the encoded data to generate image data. The image data is supplied to the display unit 930 and the received image is displayed. The audio codec 923 converts the audio data into an analog audio signal, supplies the analog audio signal to the speaker 924, and outputs the received audio.

  In the mobile phone device configured as described above, the image processing unit 927 is provided with the functions of the encoding device and the decoding device (encoding method and decoding method) of the present application. For this reason, encoding efficiency can be improved by optimizing orthogonal transformation. Also, it is possible to decode an encoded stream with improved encoding efficiency by optimizing orthogonal transform.

<Seventh embodiment>
(Configuration example of recording / reproducing apparatus)
FIG. 31 illustrates a schematic configuration of a recording / reproducing apparatus to which the present disclosure is applied. The recording / reproducing apparatus 940 records, for example, audio data and video data of a received broadcast program on a recording medium, and provides the recorded data to the user at a timing according to a user instruction. The recording / reproducing device 940 can also acquire audio data and video data from another device, for example, and record them on a recording medium. Further, the recording / reproducing apparatus 940 decodes and outputs the audio data and video data recorded on the recording medium, thereby enabling image display and audio output on the monitor apparatus or the like.

  The recording / reproducing apparatus 940 includes a tuner 941, an external interface unit 942, an encoder 943, an HDD (Hard Disk Drive) unit 944, a disk drive 945, a selector 946, a decoder 947, an OSD (On-Screen Display) unit 948, a control unit 949, A user interface unit 950 is included.

  The tuner 941 selects a desired channel from a broadcast signal received by an antenna (not shown). The tuner 941 outputs an encoded bit stream obtained by demodulating the received signal of a desired channel to the selector 946.

  The external interface unit 942 includes at least one of an IEEE 1394 interface, a network interface unit, a USB interface, a flash memory interface, and the like. The external interface unit 942 is an interface for connecting to an external device, a network, a memory card, and the like, and receives data such as video data and audio data to be recorded.

  The encoder 943 performs encoding by a predetermined method when the video data and audio data supplied from the external interface unit 942 are not encoded, and outputs an encoded bit stream to the selector 946.

  The HDD unit 944 records content data such as video and audio, various programs, and other data on a built-in hard disk, and reads them from the hard disk at the time of reproduction or the like.

  The disk drive 945 records and reproduces signals with respect to the mounted optical disk. An optical disc, for example, a DVD disc (DVD-Video, DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW, etc.), a Blu-ray (registered trademark) disc, or the like.

  The selector 946 selects one of the encoded bit streams from the tuner 941 or the encoder 943 and supplies it to either the HDD unit 944 or the disk drive 945 when recording video or audio. Further, the selector 946 supplies the encoded bit stream output from the HDD unit 944 or the disk drive 945 to the decoder 947 at the time of reproduction of video and audio.

  The decoder 947 performs a decoding process on the encoded bitstream. The decoder 947 supplies the video data generated by performing the decoding process to the OSD unit 948. The decoder 947 outputs audio data generated by performing the decoding process.

  The OSD unit 948 generates video data for displaying a menu screen for selecting an item and the like, and superimposes the video data on the video data output from the decoder 947 and outputs the video data.

  A user interface unit 950 is connected to the control unit 949. The user interface unit 950 includes an operation switch, a remote control signal receiving unit, and the like, and supplies an operation signal corresponding to a user operation to the control unit 949.

  The control unit 949 is configured using a CPU, a memory, and the like. The memory stores programs executed by the CPU and various data necessary for the CPU to perform processing. The program stored in the memory is read and executed by the CPU at a predetermined timing such as when the recording / reproducing apparatus 940 is activated. The CPU executes the program to control each unit so that the recording / reproducing device 940 operates according to the user operation.

  In the recording / reproducing apparatus configured as described above, the decoder 947 is provided with the function of the decoding apparatus (decoding method) of the present application. For this reason, it is possible to decode an encoded stream with improved encoding efficiency by optimizing the orthogonal transform.

<Eighth embodiment>
(Configuration example of imaging device)
FIG. 32 illustrates a schematic configuration of an imaging apparatus to which the present disclosure is applied. The imaging device 960 images a subject, displays an image of the subject on a display unit, and records it on a recording medium as image data.

  The imaging device 960 includes an optical block 961, an imaging unit 962, a camera signal processing unit 963, an image data processing unit 964, a display unit 965, an external interface unit 966, a memory unit 967, a media drive 968, an OSD unit 969, and a control unit 970. Have. In addition, a user interface unit 971 is connected to the control unit 970. Furthermore, the image data processing unit 964, the external interface unit 966, the memory unit 967, the media drive 968, the OSD unit 969, the control unit 970, and the like are connected via a bus 972.

  The optical block 961 is configured using a focus lens, a diaphragm mechanism, and the like. The optical block 961 forms an optical image of the subject on the imaging surface of the imaging unit 962. The imaging unit 962 is configured using a CCD or CMOS image sensor, generates an electrical signal corresponding to the optical image by photoelectric conversion, and supplies the electrical signal to the camera signal processing unit 963.

  The camera signal processing unit 963 performs various camera signal processes such as knee correction, gamma correction, and color correction on the electrical signal supplied from the imaging unit 962. The camera signal processing unit 963 supplies the image data after the camera signal processing to the image data processing unit 964.

  The image data processing unit 964 performs an encoding process on the image data supplied from the camera signal processing unit 963. The image data processing unit 964 supplies the encoded data generated by performing the encoding process to the external interface unit 966 and the media drive 968. Further, the image data processing unit 964 performs a decoding process on the encoded data supplied from the external interface unit 966 and the media drive 968. The image data processing unit 964 supplies the image data generated by performing the decoding process to the display unit 965. Further, the image data processing unit 964 superimposes the processing for supplying the image data supplied from the camera signal processing unit 963 to the display unit 965 and the display data acquired from the OSD unit 969 on the image data. To supply.

  The OSD unit 969 generates display data such as a menu screen or an icon made up of symbols, characters, or graphics and outputs it to the image data processing unit 964.

  The external interface unit 966 includes, for example, a USB input / output terminal, and is connected to a printer when printing an image. In addition, a drive is connected to the external interface unit 966 as necessary, a removable medium such as a magnetic disk or an optical disk is appropriately mounted, and a computer program read from them is installed as necessary. Furthermore, the external interface unit 966 has a network interface connected to a predetermined network such as a LAN or the Internet. For example, the control unit 970 reads encoded data from the media drive 968 in accordance with an instruction from the user interface unit 971, and supplies the encoded data to the other device connected via the network from the external interface unit 966. it can. Also, the control unit 970 may acquire encoded data and image data supplied from another device via the network via the external interface unit 966 and supply the acquired data to the image data processing unit 964. it can.

  As a recording medium driven by the media drive 968, any readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory is used. The recording medium may be any type of removable medium, and may be a tape device, a disk, or a memory card. Of course, a non-contact IC (Integrated Circuit) card may be used.

  Further, the media drive 968 and the recording medium may be integrated and configured by a non-portable storage medium such as a built-in hard disk drive or an SSD (Solid State Drive).

  The control unit 970 is configured using a CPU. The memory unit 967 stores a program executed by the control unit 970, various data necessary for the control unit 970 to perform processing, and the like. The program stored in the memory unit 967 is read and executed by the control unit 970 at a predetermined timing such as when the imaging device 960 is activated. The control unit 970 controls each unit so that the imaging device 960 performs an operation according to a user operation by executing a program.

  In the imaging device configured as described above, the image data processing unit 964 is provided with the functions of the encoding device and the decoding device (encoding method and decoding method) of the present application. For this reason, encoding efficiency can be improved by optimizing orthogonal transformation. Also, it is possible to decode an encoded stream with improved encoding efficiency by optimizing orthogonal transform.

<Application example of scalable coding>
(First system)
Next, a specific usage example of scalable encoded data that has been subjected to scalable encoding (hierarchical encoding) will be described. Scalable encoding is used for selection of data to be transmitted, as in the example shown in FIG. 33, for example.

  In the data transmission system 1000 shown in FIG. 33, the distribution server 1002 reads the scalable encoded data stored in the scalable encoded data storage unit 1001, and via the network 1003, the personal computer 1004, the AV device 1005, the tablet This is distributed to the terminal device such as the device 1006 and the mobile phone 1007.

  At that time, the distribution server 1002 selects and transmits encoded data of appropriate quality according to the capability of the terminal device, the communication environment, and the like. Even if the distribution server 1002 transmits unnecessarily high-quality data, the terminal device does not always obtain a high-quality image, and may cause a delay or an overflow. Moreover, there is a possibility that the communication band is unnecessarily occupied or the load on the terminal device is unnecessarily increased. On the other hand, even if the distribution server 1002 transmits unnecessarily low quality data, there is a possibility that an image with sufficient image quality cannot be obtained in the terminal device. Therefore, the distribution server 1002 appropriately reads and transmits the scalable encoded data stored in the scalable encoded data storage unit 1001 as encoded data having an appropriate quality with respect to the capability and communication environment of the terminal device. .

  For example, it is assumed that the scalable encoded data storage unit 1001 stores scalable encoded data (BL + EL) 1011 that is encoded in a scalable manner. The scalable encoded data (BL + EL) 1011 is encoded data including both a base layer and an enhancement layer, and is a data that can be decoded to obtain both a base layer image and an enhancement layer image. It is.

  The distribution server 1002 selects an appropriate layer according to the capability of the terminal device that transmits data, the communication environment, and the like, and reads the data of that layer. For example, the distribution server 1002 reads high-quality scalable encoded data (BL + EL) 1011 from the scalable encoded data storage unit 1001 and transmits it to the personal computer 1004 and the tablet device 1006 with high processing capability as they are. . On the other hand, for example, the distribution server 1002 extracts base layer data from the scalable encoded data (BL + EL) 1011 for the AV device 1005 and the cellular phone 1007 having a low processing capability, and performs scalable encoding. Although it is data of the same content as the data (BL + EL) 1011, it is transmitted as scalable encoded data (BL) 1012 having a lower quality than the scalable encoded data (BL + EL) 1011.

  By using scalable encoded data in this way, the amount of data can be easily adjusted, so that the occurrence of delay and overflow can be suppressed, and the unnecessary increase in the load on the terminal device and communication medium can be suppressed. be able to. In addition, since scalable encoded data (BL + EL) 1011 has reduced redundancy between layers, the amount of data can be reduced as compared with the case where encoded data of each layer is used as individual data. . Therefore, the storage area of the scalable encoded data storage unit 1001 can be used more efficiently.

  Note that since various devices can be applied to the terminal device, such as the personal computer 1004 to the cellular phone 1007, the hardware performance of the terminal device varies depending on the device. Moreover, since the application which a terminal device performs is also various, the capability of the software is also various. Furthermore, the network 1003 serving as a communication medium can be applied to any communication network including wired or wireless, or both, such as the Internet and a LAN (Local Area Network), for example, and has various data transmission capabilities. Furthermore, there is a risk of change due to other communications.

  Therefore, the distribution server 1002 communicates with the terminal device that is the data transmission destination before starting data transmission, and the hardware performance of the terminal device, the performance of the application (software) executed by the terminal device, etc. Information regarding the capability of the terminal device and information regarding the communication environment such as the available bandwidth of the network 1003 may be obtained. The distribution server 1002 may select an appropriate layer based on the information obtained here.

  Note that the layer extraction may be performed by the terminal device. For example, the personal computer 1004 may decode the transmitted scalable encoded data (BL + EL) 1011 and display a base layer image or an enhancement layer image. Further, for example, the personal computer 1004 extracts the base layer scalable encoded data (BL) 1012 from the transmitted scalable encoded data (BL + EL) 1011 and stores it or transfers it to another device. The base layer image may be displayed after decoding.

  Of course, the numbers of the scalable encoded data storage unit 1001, the distribution server 1002, the network 1003, and the terminal devices are arbitrary. In the above, the example in which the distribution server 1002 transmits data to the terminal device has been described, but the usage example is not limited to this. The data transmission system 1000 may be any system as long as it transmits a scalable encoded data to a terminal device by selecting an appropriate layer according to the capability of the terminal device or a communication environment. Can be applied to the system.

(Second system)
Further, scalable coding is used for transmission via a plurality of communication media as in the example shown in FIG. 34, for example.

  In the data transmission system 1100 shown in FIG. 34, a broadcasting station 1101 transmits base layer scalable encoded data (BL) 1121 by terrestrial broadcasting 1111. Also, the broadcast station 1101 transmits enhancement layer scalable encoded data (EL) 1122 via an arbitrary network 1112 including a wired or wireless communication network or both (for example, packetized transmission).

  The terminal device 1102 has a reception function of the terrestrial broadcast 1111 broadcasted by the broadcast station 1101, and receives base layer scalable encoded data (BL) 1121 transmitted via the terrestrial broadcast 1111. The terminal apparatus 1102 further has a communication function for performing communication via the network 1112, and receives enhancement layer scalable encoded data (EL) 1122 transmitted via the network 1112.

  The terminal device 1102 decodes the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 according to, for example, a user instruction, and obtains or stores a base layer image. Or transmit to other devices.

  Also, the terminal device 1102, for example, in response to a user instruction, the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 and the enhancement layer scalable encoded acquired via the network 1112 Data (EL) 1122 is combined to obtain scalable encoded data (BL + EL), or decoded to obtain an enhancement layer image, stored, or transmitted to another device.

  As described above, scalable encoded data can be transmitted via a different communication medium for each layer, for example. Therefore, the load can be distributed, and the occurrence of delay and overflow can be suppressed.

  Moreover, you may enable it to select the communication medium used for transmission for every layer according to a condition. For example, scalable encoded data (BL) 1121 of a base layer having a relatively large amount of data is transmitted via a communication medium having a wide bandwidth, and scalable encoded data (EL) 1122 having a relatively small amount of data is transmitted. You may make it transmit via a communication medium with a narrow bandwidth. Further, for example, the communication medium for transmitting the enhancement layer scalable encoded data (EL) 1122 is switched between the network 1112 and the terrestrial broadcast 1111 according to the available bandwidth of the network 1112. May be. Of course, the same applies to data of an arbitrary layer.

  By controlling in this way, an increase in load in data transmission can be further suppressed.

  Of course, the number of layers is arbitrary, and the number of communication media used for transmission is also arbitrary. In addition, the number of terminal devices 1102 serving as data distribution destinations is also arbitrary. Furthermore, in the above description, broadcasting from the broadcasting station 1101 has been described as an example, but the usage example is not limited to this. The data transmission system 1100 can be applied to any system as long as it is a system that divides scalable encoded data into a plurality of layers and transmits them through a plurality of lines.

(Third system)
Further, scalable encoding is used for storing encoded data as in the example shown in FIG. 35, for example.

  In the imaging system 1200 illustrated in FIG. 35, the imaging device 1201 performs scalable coding on image data obtained by imaging the subject 1211, and as scalable coded data (BL + EL) 1221, a scalable coded data storage device 1202. To supply.

  The scalable encoded data storage device 1202 stores the scalable encoded data (BL + EL) 1221 supplied from the imaging device 1201 with quality according to the situation. For example, in the normal case, the scalable encoded data storage device 1202 extracts base layer data from the scalable encoded data (BL + EL) 1221, and the base layer scalable encoded data ( BL) 1222. On the other hand, for example, in the case of attention, the scalable encoded data storage device 1202 stores scalable encoded data (BL + EL) 1221 with high quality and a large amount of data.

  By doing so, the scalable encoded data storage device 1202 can store an image with high image quality only when necessary, so that an increase in the amount of data can be achieved while suppressing a reduction in the value of the image due to image quality degradation. And the use efficiency of the storage area can be improved.

  For example, it is assumed that the imaging device 1201 is a surveillance camera. When the monitoring target (for example, an intruder) is not shown in the captured image (in the normal case), the content of the captured image is likely to be unimportant, so reduction of the data amount is given priority, and the image data (scalable coding) Data) is stored in low quality. On the other hand, when the monitoring target appears in the captured image as the subject 1211 (at the time of attention), since the content of the captured image is likely to be important, the image quality is given priority and the image data (scalable) (Encoded data) is stored with high quality.

  Note that whether it is normal time or attention time may be determined, for example, by the scalable encoded data storage device 1202 analyzing an image. Alternatively, the imaging apparatus 1201 may make a determination, and the determination result may be transmitted to the scalable encoded data storage device 1202.

  Note that the criterion for determining whether the time is normal or the time of attention is arbitrary, and the content of the image as the criterion is arbitrary. Of course, conditions other than the contents of the image can also be used as the criterion. For example, it may be switched according to the volume or waveform of the recorded sound, may be switched at every predetermined time, or may be switched by an external instruction such as a user instruction.

  In the above, an example of switching between the normal state and the attention state has been described. However, the number of states is arbitrary, for example, normal, slightly attention, attention, very attention, etc. Alternatively, three or more states may be switched. However, the upper limit number of states to be switched depends on the number of layers of scalable encoded data.

  In addition, the imaging apparatus 1201 may determine the number of scalable coding layers according to the state. For example, in a normal case, the imaging apparatus 1201 may generate base layer scalable encoded data (BL) 1222 with low quality and a small amount of data, and supply the scalable encoded data storage apparatus 1202 to the scalable encoded data storage apparatus 1202. For example, when attention is paid, the imaging device 1201 generates scalable encoded data (BL + EL) 1221 having a high quality and a large amount of data, and supplies the scalable encoded data storage device 1202 to the scalable encoded data storage device 1202. May be.

  In the above, the monitoring camera has been described as an example, but the use of the imaging system 1200 is arbitrary and is not limited to the monitoring camera.

<Ninth Embodiment>
(Other examples of implementation)
In the above, examples of apparatuses and systems to which the present disclosure is applied have been described. However, the present disclosure is not limited thereto, and any configuration mounted on such apparatuses or apparatuses constituting the system, for example, system LSI (Large Scale) Integration) etc., a module using a plurality of processors, etc., a unit using a plurality of modules, etc., a set in which other functions are added to the unit, etc. (that is, a partial configuration of the apparatus) .

(Video set configuration example)
An example of implementing the present disclosure as a set will be described with reference to FIG. FIG. 36 illustrates an example of a schematic configuration of a video set to which the present disclosure is applied.

  In recent years, multi-functionalization of electronic devices has progressed, and in the development and manufacture, when implementing a part of the configuration as sales or provision, etc., not only when implementing as a configuration having one function, but also related In many cases, a plurality of configurations having functions are combined and implemented as a set having a plurality of functions.

  The video set 1300 shown in FIG. 36 has such a multi-functional configuration, and a device having a function relating to image encoding and decoding (either or both of them) can be used for the function. It is a combination of devices having other related functions.

  As shown in FIG. 36, the video set 1300 includes a module group such as a video module 1311, an external memory 1312, a power management module 1313, and a front-end module 1314, and an associated module 1321, a camera 1322, a sensor 1323, and the like. And a device having a function.

  A module is a component having a coherent function by combining several component functions related to each other. The specific physical configuration is arbitrary. For example, a plurality of processors each having a function, electronic circuit elements such as resistors and capacitors, and other devices arranged on a wiring board or the like can be considered. . It is also possible to combine the module with another module, a processor, etc. to make a new module.

  In the case of the example in FIG. 36, the video module 1311 is a combination of configurations having functions related to image processing, and includes an application processor, a video processor, a broadband modem 1333, and an RF module 1334.

  The processor is a configuration in which a configuration having a predetermined function is integrated on a semiconductor chip by an SoC (System On a Chip). For example, there is a processor called a system LSI (Large Scale Integration). The configuration having the predetermined function may be a logic circuit (hardware configuration), a CPU, a ROM, a RAM, and the like, and a program (software configuration) executed using them. , Or a combination of both. For example, a processor has a logic circuit and a CPU, ROM, RAM, etc., a part of the function is realized by a logic circuit (hardware configuration), and other functions are executed by the CPU (software configuration) It may be realized by.

  An application processor 1331 in FIG. 36 is a processor that executes an application related to image processing. The application executed in the application processor 1331 not only performs arithmetic processing to realize a predetermined function, but also can control the internal and external configurations of the video module 1311 such as the video processor 1332 as necessary. .

  The video processor 1332 is a processor having a function relating to image encoding / decoding (one or both of them).

  The broadband modem 1333 is a processor (or module) that performs processing related to wired or wireless (or both) broadband communication performed via a broadband line such as the Internet or a public telephone line network. For example, the broadband modem 1333 digitally modulates data to be transmitted (digital signal) to convert it into an analog signal, or demodulates the received analog signal to convert it into data (digital signal). For example, the broadband modem 1333 can digitally modulate and demodulate arbitrary information such as image data processed by the video processor 1332, a stream obtained by encoding the image data, an application program, setting data, and the like.

  The RF module 1334 is a module that performs frequency conversion, modulation / demodulation, amplification, filter processing, and the like on an RF (Radio Frequency) signal transmitted and received via an antenna. For example, the RF module 1334 generates an RF signal by performing frequency conversion or the like on the baseband signal generated by the broadband modem 1333. Further, for example, the RF module 1334 generates a baseband signal by performing frequency conversion or the like on the RF signal received via the front end module 1314.

  Note that, as indicated by a dotted line 1341 in FIG. 36, the application processor 1331 and the video processor 1332 may be integrated into a single processor.

  The external memory 1312 is a module having a storage device that is provided outside the video module 1311 and is used by the video module 1311. The storage device of the external memory 1312 may be realized by any physical configuration, but is generally used for storing a large amount of data such as image data in units of frames. For example, it is desirable to realize it by a relatively inexpensive and large-capacity semiconductor memory such as a DRAM (Dynamic Random Access Memory).

  The power management module 1313 manages and controls power supply to the video module 1311 (each component in the video module 1311).

  The front-end module 1314 is a module that provides the RF module 1334 with a front-end function (a circuit on a transmitting / receiving end on the antenna side). As illustrated in FIG. 36, the front end module 1314 includes, for example, an antenna unit 1351, a filter 1352, and an amplification unit 1353.

  The antenna unit 1351 has an antenna that transmits and receives radio signals and a peripheral configuration thereof. The antenna unit 1351 transmits the signal supplied from the amplification unit 1353 as a radio signal, and supplies the received radio signal to the filter 1352 as an electric signal (RF signal). The filter 1352 performs a filtering process on the RF signal received via the antenna unit 1351 and supplies the processed RF signal to the RF module 1334. The amplifying unit 1353 amplifies the RF signal supplied from the RF module 1334 and supplies the amplified RF signal to the antenna unit 1351.

  The connectivity 1321 is a module having a function related to connection with the outside. The physical configuration of the connectivity 1321 is arbitrary. For example, the connectivity 1321 has a configuration having a communication function other than the communication standard supported by the broadband modem 1333, an external input / output terminal, and the like.

  For example, the connectivity 1321 is compliant with wireless communication standards such as Bluetooth (registered trademark), IEEE 802.11 (for example, Wi-Fi (Wireless Fidelity, registered trademark)), NFC (Near Field Communication), IrDA (InfraRed Data Association), etc. You may make it have a module which has a function, an antenna etc. which transmit / receive the signal based on the standard. Further, for example, the connectivity 1321 has a module having a communication function compliant with a wired communication standard such as USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), and a terminal compliant with the standard. You may do it. Further, for example, the connectivity 1321 may have other data (signal) transmission functions such as analog input / output terminals.

  The connectivity 1321 may include a data (signal) transmission destination device. For example, the drive 1321 reads / writes data to / from a recording medium such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory (not only a removable medium drive, but also a hard disk, SSD (Solid State Drive) And NAS (Network Attached Storage) etc.). In addition, the connectivity 1321 may include an image or audio output device (a monitor, a speaker, or the like).

  The camera 1322 is a module having a function of capturing a subject and obtaining image data of the subject. Image data obtained by imaging by the camera 1322 is supplied to, for example, a video processor 1332 and encoded.

  The sensor 1323 includes, for example, a voice sensor, an ultrasonic sensor, an optical sensor, an illuminance sensor, an infrared sensor, an image sensor, a rotation sensor, an angle sensor, an angular velocity sensor, a velocity sensor, an acceleration sensor, an inclination sensor, a magnetic identification sensor, an impact sensor, It is a module having an arbitrary sensor function such as a temperature sensor. For example, the data detected by the sensor 1323 is supplied to the application processor 1331 and used by an application or the like.

  The configuration described as a module in the above may be realized as a processor, or conversely, the configuration described as a processor may be realized as a module.

  In the video set 1300 having the above configuration, the present disclosure can be applied to the video processor 1332 as described later. Accordingly, the video set 1300 can be implemented as a set to which the present disclosure is applied.

(Video processor configuration example)
FIG. 37 illustrates an example of a schematic configuration of the video processor 1332 (FIG. 36) to which the present disclosure is applied.

  In the case of the example of FIG. 37, the video processor 1332 receives the video signal and the audio signal, encodes them in a predetermined method, decodes the encoded video data and audio data, A function of reproducing and outputting an audio signal.

  As shown in FIG. 37, the video processor 1332 includes a video input processing unit 1401, a first image enlargement / reduction unit 1402, a second image enlargement / reduction unit 1403, a video output processing unit 1404, a frame memory 1405, and a memory control unit 1406. Have The video processor 1332 includes an encoding / decoding engine 1407, video ES (Elementary Stream) buffers 1408A and 1408B, and audio ES buffers 1409A and 1409B. Further, the video processor 1332 includes an audio encoder 1410, an audio decoder 1411, a multiplexing unit (MUX (Multiplexer)) 1412, a demultiplexing unit (DMUX (Demultiplexer)) 1413, and a stream buffer 1414.

  The video input processing unit 1401 acquires a video signal input from, for example, the connectivity 1321 (FIG. 36) and converts it into digital image data. The first image enlargement / reduction unit 1402 performs format conversion, image enlargement / reduction processing, and the like on the image data. The second image enlargement / reduction unit 1403 performs image enlargement / reduction processing on the image data in accordance with the format of the output destination via the video output processing unit 1404, or is the same as the first image enlargement / reduction unit 1402. Format conversion and image enlargement / reduction processing. The video output processing unit 1404 performs format conversion, conversion to an analog signal, and the like on the image data, and outputs the reproduced video signal to, for example, the connectivity 1321 (FIG. 36).

  The frame memory 1405 is a memory for image data shared by the video input processing unit 1401, the first image scaling unit 1402, the second image scaling unit 1403, the video output processing unit 1404, and the encoding / decoding engine 1407. . The frame memory 1405 is realized as a semiconductor memory such as a DRAM, for example.

  The memory control unit 1406 receives the synchronization signal from the encoding / decoding engine 1407, and controls the writing / reading access to the frame memory 1405 according to the access schedule to the frame memory 1405 written in the access management table 1406A. The access management table 1406A is updated by the memory control unit 1406 in accordance with processing executed by the encoding / decoding engine 1407, the first image enlargement / reduction unit 1402, the second image enlargement / reduction unit 1403, and the like.

  The encoding / decoding engine 1407 performs encoding processing of image data and decoding processing of a video stream which is data obtained by encoding the image data. For example, the encoding / decoding engine 1407 encodes the image data read from the frame memory 1405 and sequentially writes the data as a video stream in the video ES buffer 1408A. Further, for example, the video stream is sequentially read from the video ES buffer 1408B, decoded, and sequentially written in the frame memory 1405 as image data. The encoding / decoding engine 1407 uses the frame memory 1405 as a work area in the encoding and decoding. Also, the encoding / decoding engine 1407 outputs a synchronization signal to the memory control unit 1406, for example, at a timing at which processing for each macroblock is started.

  The video ES buffer 1408A buffers the video stream generated by the encoding / decoding engine 1407 and supplies the buffered video stream to the multiplexing unit (MUX) 1412. The video ES buffer 1408B buffers the video stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered video stream to the encoding / decoding engine 1407.

  The audio ES buffer 1409A buffers the audio stream generated by the audio encoder 1410 and supplies it to the multiplexing unit (MUX) 1412. The audio ES buffer 1409B buffers the audio stream supplied from the demultiplexer (DMUX) 1413 and supplies the buffered audio stream to the audio decoder 1411.

  The audio encoder 1410 converts, for example, an audio signal input from the connectivity 1321 (FIG. 36), for example, into a digital format, and encodes the audio signal according to a predetermined format such as an MPEG audio format or an AC3 (Audio Code number 3) format. The audio encoder 1410 sequentially writes an audio stream, which is data obtained by encoding an audio signal, in the audio ES buffer 1409A. The audio decoder 1411 decodes the audio stream supplied from the audio ES buffer 1409B, performs conversion to an analog signal, for example, and supplies the reproduced audio signal to, for example, the connectivity 1321 (FIG. 36).

  The multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream. The multiplexing method (that is, the format of the bit stream generated by multiplexing) is arbitrary. At the time of this multiplexing, the multiplexing unit (MUX) 1412 can also add predetermined header information or the like to the bit stream. That is, the multiplexing unit (MUX) 1412 can convert the stream format by multiplexing. For example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream to convert it into a transport stream that is a bit stream in a transfer format. Further, for example, the multiplexing unit (MUX) 1412 multiplexes the video stream and the audio stream, thereby converting the data into file format data (file data) for recording.

  The demultiplexing unit (DMUX) 1413 demultiplexes the bit stream in which the video stream and the audio stream are multiplexed by a method corresponding to the multiplexing by the multiplexing unit (MUX) 1412. That is, the demultiplexer (DMUX) 1413 extracts the video stream and the audio stream from the bit stream read from the stream buffer 1414 (separates the video stream and the audio stream). That is, the demultiplexer (DMUX) 1413 can convert the stream format by demultiplexing (inverse conversion of the conversion by the multiplexer (MUX) 1412). For example, the demultiplexer (DMUX) 1413 obtains the transport stream supplied from, for example, the connectivity 1321 and the broadband modem 1333 (both in FIG. 36) via the stream buffer 1414 and demultiplexes the transport stream. Can be converted into a video stream and an audio stream. Further, for example, the demultiplexer (DMUX) 1413 obtains the file data read from various recording media by the connectivity 1321 (FIG. 36) via the stream buffer 1414, and demultiplexes the file data, for example. It can be converted into a video stream and an audio stream.

  The stream buffer 1414 buffers the bit stream. For example, the stream buffer 1414 buffers the transport stream supplied from the multiplexing unit (MUX) 1412 and, for example, at the predetermined timing or based on a request from the outside, for example, the connectivity 1321 or the broadband modem 1333 (whichever Are also supplied to FIG.

  Further, for example, the stream buffer 1414 buffers the file data supplied from the multiplexing unit (MUX) 1412 and, for example, connectivity 1321 (FIG. 36) or the like at a predetermined timing or based on an external request or the like. To be recorded on various recording media.

  Further, the stream buffer 1414 buffers the transport stream acquired through, for example, the connectivity 1321 and the broadband modem 1333 (both of which are shown in FIG. 36), and performs reverse processing at a predetermined timing or based on an external request or the like. The data is supplied to a multiplexing unit (DMUX) 1413.

  Further, the stream buffer 1414 buffers file data read from various recording media in the connectivity 1321 (FIG. 36), for example, and at a predetermined timing or based on an external request or the like, a demultiplexing unit (DMUX) 1413.

  Next, an example of the operation of the video processor 1332 having such a configuration will be described. For example, a video signal input to the video processor 1332 from the connectivity 1321 (FIG. 36) or the like is converted into digital image data of a predetermined format such as 4: 2: 2Y / Cb / Cr format by the video input processing unit 1401. The data is sequentially written into the frame memory 1405. This digital image data is read by the first image enlargement / reduction unit 1402 or the second image enlargement / reduction unit 1403, and format conversion to a predetermined method such as 4: 2: 0Y / Cb / Cr method and enlargement / reduction processing are performed. Is written again in the frame memory 1405. This image data is encoded by the encoding / decoding engine 1407 and written as a video stream in the video ES buffer 1408A.

  Also, an audio signal input from the connectivity 1321 (FIG. 36) or the like to the video processor 1332 is encoded by the audio encoder 1410 and written as an audio stream in the audio ES buffer 1409A.

  The video stream of the video ES buffer 1408A and the audio stream of the audio ES buffer 1409A are read and multiplexed by the multiplexing unit (MUX) 1412 and converted into a transport stream or file data. The transport stream generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414 and then output to the external network via, for example, the connectivity 1321 and the broadband modem 1333 (both of which are shown in FIG. 36). Further, the file data generated by the multiplexing unit (MUX) 1412 is buffered in the stream buffer 1414, and then output to, for example, the connectivity 1321 (FIG. 36) and recorded on various recording media.

  Further, for example, a transport stream input from an external network to the video processor 1332 via the connectivity 1321 or the broadband modem 1333 (both in FIG. 36) is buffered in the stream buffer 1414 and then demultiplexed (DMUX) 1413 is demultiplexed. For example, file data read from various recording media in the connectivity 1321 (FIG. 36) and input to the video processor 1332 is buffered in the stream buffer 1414 and then demultiplexed by the demultiplexer (DMUX) 1413. It becomes. That is, the transport stream or file data input to the video processor 1332 is separated into a video stream and an audio stream by the demultiplexer (DMUX) 1413.

  The audio stream is supplied to the audio decoder 1411 via the audio ES buffer 1409B, decoded, and an audio signal is reproduced. The video stream is written to the video ES buffer 1408B, and then sequentially read and decoded by the encoding / decoding engine 1407, and written to the frame memory 1405. The decoded image data is enlarged / reduced by the second image enlargement / reduction unit 1403 and written to the frame memory 1405. The decoded image data is read out to the video output processing unit 1404, format-converted to a predetermined system such as 4: 2: 2Y / Cb / Cr system, and further converted into an analog signal to be converted into a video signal. Is played out.

  When the present disclosure is applied to the video processor 1332 configured as described above, the present disclosure according to each embodiment described above may be applied to the encoding / decoding engine 1407. That is, for example, the encoding / decoding engine 1407 may have the functions of the encoding device and the decoding device according to the first embodiment. In this way, the video processor 1332 can obtain the same effects as those described above with reference to FIGS.

  Note that in the encoding / decoding engine 1407, the present disclosure (that is, the functions of the image encoding device and the image decoding device according to each embodiment described above) may be realized by hardware such as a logic circuit, It may be realized by software such as an embedded program, or may be realized by both of them.

(Another configuration example of the video processor)
FIG. 38 illustrates another example of a schematic configuration of the video processor 1332 (FIG. 36) to which the present disclosure is applied. In the example of FIG. 38, the video processor 1332 has a function of encoding and decoding video data by a predetermined method.

  More specifically, as shown in FIG. 38, the video processor 1332 includes a control unit 1511, a display interface 1512, a display engine 1513, an image processing engine 1514, and an internal memory 1515. The video processor 1332 includes a codec engine 1516, a memory interface 1517, a multiplexing / demultiplexing unit (MUX DMUX) 1518, a network interface 1519, and a video interface 1520.

  The control unit 1511 controls the operation of each processing unit in the video processor 1332 such as the display interface 1512, the display engine 1513, the image processing engine 1514, and the codec engine 1516.

  As illustrated in FIG. 38, the control unit 1511 includes, for example, a main CPU 1531, a sub CPU 1532, and a system controller 1533. The main CPU 1531 executes a program and the like for controlling the operation of each processing unit in the video processor 1332. The main CPU 1531 generates a control signal according to the program and supplies it to each processing unit (that is, controls the operation of each processing unit). The sub CPU 1532 plays an auxiliary role of the main CPU 1531. For example, the sub CPU 1532 executes a child process such as a program executed by the main CPU 1531, a subroutine, or the like. The system controller 1533 controls operations of the main CPU 1531 and the sub CPU 1532 such as designating a program to be executed by the main CPU 1531 and the sub CPU 1532.

  The display interface 1512 outputs image data to, for example, the connectivity 1321 (FIG. 36) or the like under the control of the control unit 1511. For example, the display interface 1512 converts the digital data image data into an analog signal, and outputs it to the monitor device of the connectivity 1321 (FIG. 36) or the like as a reproduced video signal or as the digital data image data.

  Under the control of the control unit 1511, the display engine 1513 performs various conversion processes such as format conversion, size conversion, color gamut conversion, and the like so as to match the image data with hardware specifications such as a monitor device that displays the image. I do.

  The image processing engine 1514 performs predetermined image processing such as filter processing for improving image quality on the image data under the control of the control unit 1511.

  The internal memory 1515 is a memory provided in the video processor 1332 that is shared by the display engine 1513, the image processing engine 1514, and the codec engine 1516. The internal memory 1515 is used, for example, for data exchange performed between the display engine 1513, the image processing engine 1514, and the codec engine 1516. For example, the internal memory 1515 stores data supplied from the display engine 1513, the image processing engine 1514, or the codec engine 1516, and stores the data as needed (eg, upon request). This is supplied to the image processing engine 1514 or the codec engine 1516. The internal memory 1515 may be realized by any storage device, but is generally used for storing a small amount of data such as image data or parameters in units of blocks. It is desirable to realize it by a semiconductor memory such as a static random access memory that has a relatively small capacity (eg, compared to the external memory 1312) but a high response speed.

  The codec engine 1516 performs processing related to encoding and decoding of image data. The encoding / decoding scheme supported by the codec engine 1516 is arbitrary, and the number thereof may be one or plural. For example, the codec engine 1516 may be provided with codec functions of a plurality of encoding / decoding schemes, and may be configured to perform encoding of image data or decoding of encoded data using one selected from them.

  In the example shown in FIG. 38, the codec engine 1516 includes, for example, MPEG-2 Video 1541, AVC / H.2641542, HEVC / H.2651543, HEVC / H.265 (Scalable) 1544, as functional blocks for processing related to the codec. HEVC / H.265 (Multi-view) 1545 and MPEG-DASH 1551 are included.

  MPEG-2 Video 1541 is a functional block that encodes and decodes image data in the MPEG-2 format. AVC / H.2641542 is a functional block that encodes and decodes image data using the AVC method. HEVC / H.2651543 is a functional block that encodes and decodes image data using the HEVC method. HEVC / H.265 (Scalable) 1544 is a functional block that performs scalable encoding and scalable decoding of image data using the HEVC method. HEVC / H.265 (Multi-view) 1545 is a functional block that multi-view encodes or multi-view decodes image data using the HEVC method.

  MPEG-DASH 1551 is a functional block that transmits and receives image data by the MPEG-DASH (MPEG-Dynamic Adaptive Streaming over HTTP) method. MPEG-DASH is a technology for streaming video using HTTP (HyperText Transfer Protocol), and selects and transmits appropriate data from multiple encoded data with different resolutions prepared in segments. This is one of the features. MPEG-DASH 1551 generates a stream conforming to the standard, controls transmission of the stream, and the like. For encoding / decoding of image data, MPEG-2 Video 1541 to HEVC / H.265 (Multi-view) 1545 described above are used. Is used.

  The memory interface 1517 is an interface for the external memory 1312. Data supplied from the image processing engine 1514 or the codec engine 1516 is supplied to the external memory 1312 via the memory interface 1517. The data read from the external memory 1312 is supplied to the video processor 1332 (the image processing engine 1514 or the codec engine 1516) via the memory interface 1517.

  A multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes and demultiplexes various data related to images such as a bit stream of encoded data, image data, and a video signal. This multiplexing / demultiplexing method is arbitrary. For example, at the time of multiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can not only combine a plurality of data into one but also add predetermined header information or the like to the data. Further, in the demultiplexing, the multiplexing / demultiplexing unit (MUX DMUX) 1518 not only divides one data into a plurality of data but also adds predetermined header information or the like to each divided data. it can. That is, the multiplexing / demultiplexing unit (MUX DMUX) 1518 can convert the data format by multiplexing / demultiplexing. For example, the multiplexing / demultiplexing unit (MUX DMUX) 1518 multiplexes the bit stream, thereby transporting a transport stream that is a bit stream in a transfer format and data in a file format for recording (file data). Can be converted to Of course, the inverse transformation is also possible by demultiplexing.

  The network interface 1519 is an interface for a broadband modem 1333, connectivity 1321 (both of which are shown in FIG. 36), and the like. The video interface 1520 is an interface for, for example, the connectivity 1321 and the camera 1322 (both are FIG. 36).

  Next, an example of the operation of the video processor 1332 will be described. For example, when a transport stream is received from an external network via, for example, the connectivity 1321 or the broadband modem 1333 (both of which are shown in FIG. 36), the transport stream is transmitted to the multiplexing / demultiplexing unit (MUX) via the network interface 1519. DMUX) 1518 is demultiplexed and decoded by the codec engine 1516. For example, the image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and connected to, for example, the connectivity 1321 (see FIG. 36) and the image is displayed on the monitor. Further, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by a multiplexing / demultiplexing unit (MUX DMUX) 1518, converted into file data, and video data The data is output to, for example, the connectivity 1321 (FIG. 36) via the interface 1520 and recorded on various recording media.

  Further, for example, encoded data file data obtained by encoding image data read from a recording medium (not shown) by the connectivity 1321 (FIG. 36) is multiplexed / demultiplexed via the video interface 1520. Is supplied to a unit (MUX DMUX) 1518, demultiplexed, and decoded by a codec engine 1516. Image data obtained by decoding by the codec engine 1516 is subjected to predetermined image processing by the image processing engine 1514, subjected to predetermined conversion by the display engine 1513, and, for example, connectivity 1321 via the display interface 1512 (FIG. 36). And the image is displayed on the monitor. Further, for example, image data obtained by decoding by the codec engine 1516 is re-encoded by the codec engine 1516, multiplexed by a multiplexing / demultiplexing unit (MUX DMUX) 1518, and converted into a transport stream, The data is supplied to, for example, the connectivity 1321 and the broadband modem 1333 (both of which are shown in FIG. 36) via the network interface 1519 and transmitted to another device (not shown).

  Note that transfer of image data and other data between the processing units in the video processor 1332 is performed using, for example, the internal memory 1515 and the external memory 1312. The power management module 1313 controls power supply to the control unit 1511, for example.

  When the present disclosure is applied to the video processor 1332 configured as described above, the present disclosure according to each embodiment described above may be applied to the codec engine 1516. That is, for example, the codec engine 1516 may have a functional block that realizes the encoding device and the decoding device according to the first embodiment. Further, for example, by the codec engine 1516 doing this, the video processor 1332 can obtain the same effects as those described above with reference to FIGS. 1 to 18.

  Note that in the codec engine 1516, the present disclosure (that is, the functions of the image encoding device and the image decoding device according to each of the embodiments described above) may be realized by hardware such as a logic circuit, or an embedded program. It may be realized by software such as the above, or may be realized by both of them.

  Two examples of the configuration of the video processor 1332 have been described above, but the configuration of the video processor 1332 is arbitrary and may be other than the two examples described above. The video processor 1332 may be configured as one semiconductor chip, but may be configured as a plurality of semiconductor chips. For example, a three-dimensional stacked LSI in which a plurality of semiconductors are stacked may be used. Further, it may be realized by a plurality of LSIs.

  (Application example for equipment)

  Video set 1300 can be incorporated into various devices that process image data. For example, the video set 1300 can be incorporated in the television device 900 (FIG. 29), the mobile phone 920 (FIG. 30), the recording / reproducing device 940 (FIG. 31), the imaging device 960 (FIG. 32), or the like. By incorporating the video set 1300, the apparatus can obtain the same effects as those described above with reference to FIGS.

  In addition, the video set 1300 includes, for example, terminal devices such as the personal computer 1004, the AV device 1005, the tablet device 1006, and the mobile phone 1007 in the data transmission system 1000 in FIG. 33, the broadcasting station 1101 in the data transmission system 1100 in FIG. The terminal device 1102 and the imaging device 1201 and the scalable encoded data storage device 1202 in the imaging system 1200 of FIG. 35 can be incorporated. By incorporating the video set 1300, the apparatus can obtain the same effects as those described above with reference to FIGS.

  Note that even a part of each configuration of the video set 1300 described above can be implemented as a configuration to which the present disclosure is applied as long as it includes the video processor 1332. For example, only the video processor 1332 can be implemented as a video processor to which the present disclosure is applied. For example, as described above, the processor, the video module 1311, and the like indicated by the dotted line 1341 can be implemented as a processor, a module, or the like to which the present disclosure is applied. Furthermore, for example, the video module 1311, the external memory 1312, the power management module 1313, and the front end module 1314 can be combined and implemented as a video unit 1361 to which the present disclosure is applied. In any case, the same effects as those described above with reference to FIGS. 1 to 18 can be obtained.

  That is, any configuration including the video processor 1332 can be incorporated into various devices that process image data, as in the case of the video set 1300. For example, a video processor 1332, a processor indicated by a dotted line 1341, a video module 1311, or a video unit 1361, a television device 900 (FIG. 29), a cellular phone 920 (FIG. 30), a recording / playback device 940 (FIG. 31), Imaging device 960 (FIG. 32), terminal devices such as personal computer 1004, AV device 1005, tablet device 1006, and mobile phone 1007 in data transmission system 1000 in FIG. 33, broadcast station 1101 and terminal in data transmission system 1100 in FIG. It can be incorporated into the device 1102, the imaging device 1201 and the scalable encoded data storage device 1202 in the imaging system 1200 of FIG. Then, by incorporating any configuration to which the present disclosure is applied, the apparatus can obtain the same effects as those described above with reference to FIGS. 1 to 18 as in the case of the video set 1300. .

  In the present specification, an example in which various types of information are multiplexed with encoded data and transmitted from the encoding side to the decoding side has been described. However, the method for transmitting such information is not limited to such an example. For example, these pieces of information may be transmitted or recorded as separate data associated with the encoded data without being multiplexed with the encoded data. Here, the term “associate” means that an image (which may be a part of an image such as a slice or a block) included in the bitstream and information corresponding to the image can be linked at the time of decoding. Means. That is, the information may be transmitted on a transmission path different from the encoded data. The information may be recorded on a recording medium different from the encoded data (or another recording area of the same recording medium). Furthermore, the information and the encoded data may be associated with each other in an arbitrary unit such as a plurality of frames, one frame, or a part of the frame.

  In this specification, the system means a set of a plurality of components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Accordingly, a plurality of devices housed in separate housings and connected via a network and a single device housing a plurality of modules in one housing are all systems. .

  The effects described in this specification are merely examples and are not limited, and may have other effects.

  Embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

  For example, the size of the TU when determining the orthogonal transform (or inverse orthogonal transform) method according to the distance between the TU and the surrounding image is not limited to 4 × 4 pixels.

  The present disclosure also relates to an encoding device (for example, MPEG, H.26x, etc.) other than the HEVC method that performs orthogonal transform by dividing a PU during intra prediction into a plurality of square TUs. Can also be applied.

  In addition, the present disclosure also relates to a case where an encoded stream is received via a network medium such as satellite broadcasting, cable TV, the Internet, or a mobile phone, or is processed on a storage medium such as an optical, magnetic disk, or flash memory. The present invention can be applied to an encoding device and a decoding device used in the above.

  Furthermore, the present disclosure can take a cloud computing configuration in which one function is shared by a plurality of devices via a network and is jointly processed.

  In addition, each step described in the above flowchart can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

  Furthermore, when a plurality of processes are included in one step, the plurality of processes included in the one step can be executed by being shared by a plurality of apparatuses in addition to being executed by one apparatus.

  In addition, the present disclosure can have the following configurations.

(1)
A receiving unit for receiving an orthogonal transform coefficient obtained by orthogonal transform of a difference between a predicted image of the image and the image in units of transform blocks;
The method of inverse orthogonal transform for the orthogonal transform coefficient received by the receiving unit is determined according to the distance between the transform block and the predicted image and the neighboring image adjacent to the inverse orthogonal transform in the transform block unit. A determination unit for determining
A decoding apparatus comprising: an inverse orthogonal transform unit that performs inverse orthogonal transform on the orthogonal transform coefficient of each transform block in the method of the inverse orthogonal transform determined by the determination unit.
(2)
The decoding apparatus according to (1), further including an intra prediction unit that generates the predicted image by intra prediction using the peripheral image.
(3)
The decoding device according to (2), wherein the determination unit is configured to determine that the inverse orthogonal transform method is an inverse discrete sine transform when the peripheral image is in contact with the transform block.
(4)
The decoding device according to (2) or (3), wherein the determination unit is configured to determine that the inverse orthogonal transform method is an inverse discrete cosine transform when the surrounding image and the transform block are not in contact with each other. .
(5)
The decoding device according to any one of (1) to (4), wherein the conversion block is configured to have 4 × 4 pixels.
(6)
The format of the image is 4: 2: 2.
The decoding device according to (5), wherein the reception unit is configured to receive the orthogonal transform coefficient of a color difference signal of 4 × 8 pixels of the image.
(7)
The decryption device
Receiving an orthogonal transform coefficient obtained by orthogonal transform of a difference between the predicted image of the image and the image on a transform block basis;
The method of inverse orthogonal transform for the orthogonal transform coefficient received by the processing of the receiving step is a distance between the transform block and a neighboring image adjacent to the predicted image and the inverse orthogonal transform in the transform block unit. A determination step for determining according to
An inverse orthogonal transform step and a decoding method, wherein the transform block unit orthogonal transform coefficient is subjected to inverse orthogonal transform by the inverse orthogonal transform method determined by the determination step processing.
(8)
An orthogonal transform method for orthogonally transforming a difference between a predicted image of the image and the image in units of transform blocks, the transform block, and neighboring images adjacent to the predicted image in the direction of the orthogonal transform in the transform block unit. A determination unit for determining according to the distance between
An encoding device comprising: an orthogonal transform unit that orthogonally transforms the difference of the transform block unit by the orthogonal transform method determined by the determination unit.
(9)
The encoding apparatus according to (8), further including: an intra prediction unit that generates the predicted image by intra prediction using the peripheral image.
(10)
The encoding device according to (9), wherein the determination unit is configured to determine that the orthogonal transform method is a discrete sine transform when the peripheral image is in contact with the transform block.
(11)
The encoding device according to (9) or (10), wherein the determination unit is configured to determine that the orthogonal transform method is a discrete cosine transform when the peripheral image is not in contact with the transform block.
(12)
The encoding device according to any one of (8) to (11), wherein the transform block is configured to have 4 × 4 pixels.
(13)
The format of the image is 4: 2: 2.
The encoding device according to (12), wherein the orthogonal transform unit is configured to perform orthogonal transform on the difference of the color difference signal of 4 × 8 pixels of the image.
(14)
The encoding device
An orthogonal transform method for orthogonally transforming a difference between a predicted image of the image and the image in units of transform blocks, the transform block, and neighboring images adjacent to the predicted image in the direction of the orthogonal transform in the transform block unit. A determination step for determining according to the distance between;
An orthogonal transform step and an encoding method for performing orthogonal transform on the difference of the transform block unit by the orthogonal transform method determined by the process of the determination step.

  DESCRIPTION OF SYMBOLS 10 encoding apparatus, 34 orthogonal transformation part, 46 intra prediction part, 50 determination part, 110 decoding apparatus, 111 receiving part, 134 inverse orthogonal transformation part, 143 intra prediction part, 147 determination part

Claims (14)

A receiving unit for receiving an orthogonal transform coefficient obtained by orthogonal transform of a difference between a predicted image of the image and the image in units of transform blocks;
The method of inverse orthogonal transform for the orthogonal transform coefficient received by the receiving unit is determined according to the distance between the transform block and the predicted image and the neighboring image adjacent to the inverse orthogonal transform in the transform block unit. A determination unit for determining
A decoding apparatus comprising: an inverse orthogonal transform unit that performs inverse orthogonal transform on the orthogonal transform coefficient of each transform block in the method of the inverse orthogonal transform determined by the determination unit. The decoding device according to claim 1, further comprising: an intra prediction unit that generates the predicted image by intra prediction using the peripheral image. The decoding device according to claim 2, wherein the determination unit is configured to determine that the inverse orthogonal transform method is an inverse discrete sine transform when the peripheral image is in contact with the transform block. The decoding device according to claim 2, wherein the determination unit is configured to determine that the inverse orthogonal transform method is an inverse discrete cosine transform when the surrounding image and the transform block are not in contact with each other. The decoding device according to claim 1, wherein the transform block is configured to have 4 × 4 pixels. The format of the image is 4: 2: 2.
The decoding device according to claim 5, wherein the reception unit is configured to receive the orthogonal transform coefficient of a color difference signal of 4x8 pixels of the image. The decryption device
Receiving an orthogonal transform coefficient obtained by orthogonal transform of a difference between the predicted image of the image and the image on a transform block basis;
The method of inverse orthogonal transform for the orthogonal transform coefficient received by the processing of the receiving step is a distance between the transform block and a neighboring image adjacent to the predicted image and the inverse orthogonal transform in the transform block unit. A determination step for determining according to
An inverse orthogonal transform step and a decoding method, wherein the transform block unit orthogonal transform coefficient is subjected to inverse orthogonal transform by the inverse orthogonal transform method determined by the determination step processing. An orthogonal transform method for orthogonally transforming a difference between a predicted image of the image and the image in units of transform blocks, the transform block, and neighboring images adjacent to the predicted image in the direction of the orthogonal transform in the transform block unit. A determination unit for determining according to the distance between
An encoding device comprising: an orthogonal transform unit that orthogonally transforms the difference of the transform block unit by the orthogonal transform method determined by the determination unit. The encoding apparatus according to claim 8, further comprising: an intra prediction unit that generates the predicted image by intra prediction using the peripheral image. The encoding device according to claim 9, wherein the determination unit is configured to determine that the orthogonal transform method is a discrete sine transform when the peripheral image is in contact with the transform block. The encoding device according to claim 9, wherein the determination unit is configured to determine that the orthogonal transform method is a discrete cosine transform when the surrounding image and the transform block are not in contact with each other. The encoding device according to claim 8, wherein the transform block is configured to have 4 × 4 pixels. The format of the image is 4: 2: 2.
The encoding device according to claim 12, wherein the orthogonal transform unit is configured to orthogonally transform the difference of the color difference signal of 4x8 pixels of the image. The encoding device
An orthogonal transform method for orthogonally transforming a difference between a predicted image of the image and the image in units of transform blocks, the transform block, and neighboring images adjacent to the predicted image in the direction of the orthogonal transform in the transform block unit. A determination step for determining according to the distance between;
An orthogonal transform step and an encoding method for performing orthogonal transform on the difference of the transform block unit by the orthogonal transform method determined by the process of the determination step.

Images