JP2001285642A - Image processing apparatus and method, computer readable memory - Google Patents

Abstract

(57) Abstract: An image processing apparatus and method capable of suitably encoding / decoding an ROI and other areas, and a computer-readable memory. SOLUTION: In an image data, a high-quality coded area to be coded with higher image quality than a surrounding area is determined by an area specifying unit 4. The discrete wavelet transform unit 2 performs orthogonal transform on the image data to generate transformed data. Each bit plane constituting the conversion data is encoded by the entropy encoding unit 5. The output order of the obtained bit-plane coded data is designated by the interleave setting unit 6. The interleaver 7 shifts the conversion data in the high-quality coding area to the higher order to compensate for the lower-order bits with zeros, and complements the higher-order bits of the conversion data outside the high-quality coding area with zeros. Then, based on the specified output order, the bit plane coded data is output by the code output unit 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and method for encoding and decoding an image, and a computer readable memory.

[0002]

2. Description of the Related Art At present, JP is used as a still image encoding method.
The EG coding method is widely used. This JPEG encoding method is based on the ISO (International Organization for S
tandardization (International Organization for Standardization). In addition, as a moving image encoding method, this JPE
Mo that uses G encoding as intraframe encoding
tion JPEG is generally known. Furthermore, with the spread of the Internet in recent years, higher performance and higher image quality encoding than the conventional JPEG encoding method is required. For this reason, the ISO is working on standardization of a new still image coding method. This activity is commonly called "JPEG2000". JPEG200
For an overview of the 0 encoding method, see "Special Article JPEG2
000 Exploring Next-Generation Imaging Technology ”(Toda: C MAGAZINE
See October 1999, pp.6-10). In particular, an area ROI (Region Of Interesting) to be decoded with higher image quality than the surrounding area, which is introduced in this document, is a new function and a useful technique.

[0003]

However, in a conventional image encoding / decoding apparatus (details will be described later), for example, when a communication line of a low-capacity network is used, only a part of the ROI is transmitted, and a part other than the ROI is transmitted. A phenomenon occurs in which the information cannot be transmitted at all. This is done so that bit planes do not overlap during decoding inside and outside the ROI area.
The bit is shifted up with respect to the OI, and R
This is because if all the bits of the OI are not decoded, no other bits are decoded.

Further, when JPEG2000 is applied to moving picture coding as intra-frame coding, rate control is required, and the number of bit planes that can be transmitted depending on the picture when adjusting the code amount may vary. There is.
In other words, the ROI and other areas can be reproduced in a certain frame, but in a certain frame, only the ROI is reproduced and the other areas may be black. Further, since the phenomenon differs for each frame, there is a problem that a reproduced image is largely disturbed. For example, when encoding three consecutive frames, and encoding and decoding of the ROI and the other areas can be performed only for the intermediate frame, FIG.
As shown in (a), (b), and (c), regions (background) other than the ROI of the frames of FIGS. 18 (a) and 18 (c) before and after the frame of FIG. 18 (b) are decoded. Without giving the user a great deal of discomfort.

The present invention has been made in view of the above problems, and provides an image processing apparatus and method capable of suitably encoding / decoding an ROI and other areas, a method thereof, and a computer-readable memory. The purpose is to:

[0006]

An image processing apparatus according to the present invention for achieving the above object has the following arrangement.
That is, an image processing device that encodes input image data, a determining unit that determines a high-quality coding region in which high-quality coding is performed in the image data than a surrounding region, and the high-quality coding region. A conversion means for shifting the conversion data in the upper bit to a higher order to compensate the lower bits with 0, and supplementing the upper bits of the conversion data outside the high-quality coding area with 0s, and performing orthogonal transformation on the image data. Conversion means for generating conversion data, coding means for coding each bit plane constituting the conversion data, and designation means for specifying the output order of each bit plane coded data obtained by the coding means, Output means for outputting the bit-plane coded data based on the output order specified by the specifying means.

Preferably, the output means includes control means for controlling bit plane coded data output from the coding means.

Preferably, the apparatus further comprises quantization means for quantizing the transformed data.

Preferably, the conversion means performs a wavelet transform on the image data to generate the converted data.

An image processing apparatus according to the present invention for achieving the above object has the following arrangement. That is, an image processing apparatus that decodes input encoded data, has a high-quality encoded area encoded with higher image quality than a surrounding area in an image, and outputs each bit plane encoded data that is configured. Input means for inputting encoded data including output-order encoded data specifying an order; and storage means for storing each bit-plane encoded data constituting the encoded data based on the output-order encoded data. A bit shift means for performing a bit shift of the encoded data stored in the storage means, a decoding means for decoding the encoded data bit-shifted by the bit shift means, and a decoder for decoding the data decoded by the decoding means. Inverse transform means for performing orthogonal transform to generate image data.

Preferably, the bit shift means bit-shifts the coded data corresponding to the high image quality area stored in the storage means to lower bits.

Preferably, the apparatus further comprises an inverse quantization means for inversely quantizing the data decoded by the decoding means.

[0013] Preferably, said inverse conversion means comprises:
The image data is generated by performing an inverse wavelet transform on the data decoded by the decoding means.

An image processing method according to the present invention for achieving the above object has the following arrangement. That is, an image processing method for encoding input image data, comprising: a determining step of determining a high-quality encoded area to be encoded with higher image quality than a surrounding area in the image data; and an orthogonal transform to the image data. A conversion step of generating conversion data by performing
A conversion step of shifting the converted data in the high-quality coding area to a higher order to fill the lower bits with zeros and filling the higher-order bits of the conversion data outside the high-quality coding area with zeros; An encoding step of encoding each bit plane that constitutes, a designation step of designating an output order of each bit plane encoded data obtained in the encoding step, based on the output order designated in the designation step, An output step of outputting the bit-plane encoded data.

An image processing method according to the present invention for achieving the above object has the following arrangement. That is, an image processing method for decoding input encoded data, comprising a high-quality encoded area encoded with higher quality than surrounding areas in an image, and outputting each bit-plane encoded data configured. An input step of inputting encoded data including output-order encoded data specifying an order; and storing each bit-plane encoded data constituting the encoded data in a storage medium based on the output-order encoded data. A storing step; a bit shifting step of performing a bit shift of the encoded data stored in the storage medium in the storing step; a decoding step of decoding the encoded data bit-shifted in the bit shifting step; Performing an inverse orthogonal transform on the data decoded in step (a) to generate image data.

A computer readable memory according to the present invention for achieving the above object has the following configuration. That is,
A computer-readable memory storing a program code of image processing for encoding input image data, wherein a determining step of determining a high-quality encoded area to encode with higher image quality than a surrounding area in the image data; A program code, a program code of a conversion step of performing orthogonal transformation on the image data to generate conversion data, a program code of an encoding step of encoding each bit plane constituting the conversion data, and the encoding step And a program code of a designating step for designating the output order of each bit plane coded data obtained in the step (a) and the converted data in the high quality coding area are bit-shifted to the high order and 0's are added to the low order bits, and The program code of the compensation step for supplementing the upper bits of the conversion data outside the coding area with 0s and the program code specified in the designation step It was based on the output order, comprising program code Toto output step of outputting the bit-plane coding data.

A computer readable memory according to the present invention for achieving the above object has the following configuration. That is,
A computer-readable memory that stores a program code of image processing for decoding input encoded data, and includes a high-quality encoded area encoded with higher image quality than a surrounding area in an image, and is configured as A program code of an input step of inputting encoded data including output order encoded data specifying an output order of bit plane encoded data, and each bit constituting the encoded data based on the output order encoded data. A program code for a storage step of storing plane encoded data in a storage medium, a program code of a bit shift step for performing a bit shift of the encoded data stored in the storage medium in the storage step, and a bit code in the bit shift step. The program code of the decoding step of decoding the shifted encoded data, and the data decoded in the decoding step And a program code for inverse conversion step of generating image data by performing orthogonal transformation.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, referring to FIG.
An image encoding device that realizes I will be described.

FIG. 12 is a block diagram showing a basic configuration of a conventional image coding apparatus for realizing an ROI.

In FIG. 12, reference numeral 1001 denotes an image input unit;
1002 is a discrete wavelet transform unit, 1003 is a quantization unit, 1004 is an entropy encoding unit, 1005 is a code output unit, and 1011 is an area designation unit.

First, pixel signals constituting an image signal to be encoded are input to the image input unit 1001 in raster-scan order. The image signal output from the image input unit 1001 is input to the discrete wavelet transform unit 1002. The discrete wavelet transform unit 1002 performs a two-dimensional discrete wavelet transform process on the input image signal, and calculates and outputs a transform coefficient.

Here, a configuration example of a two-level transform coefficient group obtained by the two-dimensional discrete wavelet transform processing will be described with reference to FIG.

FIG. 13 is a diagram showing a configuration example of a two-level transform coefficient group obtained by a two-dimensional discrete wavelet transform process.

In FIG. 13, an image signal is decomposed into coefficient sequences HH1, HL1, LH1,... LL of different frequency bands. In the following description, these coefficient sequences are called subbands. The coefficient of each subband is calculated by the following quantization unit 10
03 is output.

An area designating unit 1011 determines an area (ROI) to be decoded with high image quality in comparison with surrounding parts in an image to be encoded, and determines which pixel when the target image is subjected to discrete wavelet transform. Generates mask information indicating whether or not belongs to the ROI.

Hereinafter, the process of generating mask information will be described with reference to FIG.

As shown in FIG. 14A, when a star-shaped area is specified in an image by a predetermined instruction input, the area specifying unit 1011 performs a discrete wavelet transform on the image including the specified area. , Calculate the portion occupied by the designated region in each subband. Also, the area indicated by the mask information is
This is a range including surrounding conversion coefficients necessary for restoring an image signal on the boundary of the designated area.

An example of the mask information calculated in this way is
This is shown in FIG. In this example, FIG.
The mask information when the two-level discrete wavelet transform is performed on the image is calculated as shown in the figure. FIG.
In (b), the star-shaped portion is a designated area, and the bits of the mask information in this designated area are 1 and the bits of the other mask information are 0. Since the entire mask information is the same as the configuration of the transform coefficient by the two-dimensional discrete wavelet transform, it is determined whether the transform coefficient at the corresponding position belongs to the specified area by inspecting the bits in the mask information. can do. The mask information generated in this way is output to quantization section 1003.

The quantization section 1003 quantizes the input sub-band at a predetermined quantization step Δ, and outputs a quantization index for the obtained quantization value. Next, the quantization unit 1003 changes the quantization index based on the mask information input from the area designation unit 1011 according to the following equation.

Q ′ = q * 2 ⁸ ; inside the area (1) q ′ = q; outside the area (2) By the above processing, only the quantization index belonging to the specified area specified by the area specifying unit 1011 is 8 bits. It is shifted up.

The process of shifting up the quantization index will be described with reference to FIG.

FIG. 15A shows the quantization index of the subband, and FIG. 15B shows the quantization index after the shift. The quantization index thus shifted is output to the entropy encoding unit 1004 that follows.

The entropy coding unit 1004 decomposes the input quantization index into bit planes, performs binary arithmetic coding on a bit plane basis, and outputs a code stream.

Here, the operation of the entropy encoder 1004 will be described with reference to FIG.

FIG. 16 is a diagram showing the operation of entropy coding.

In this example, three non-zero quantization indices exist in a subband area having a size of 4 × 4, and have values of +13, −6, and +3, respectively. The entropy encoding unit 1004 scans this area to find the maximum value M, and calculates the required number of bits S.

In FIG. 16A, the maximum value M is 13
Therefore, the number of bits S required to express this is 4. Then, the 16 quantization indices in the sequence are processed in units of four bit planes as shown in FIG. First, the entropy coding unit 1004 outputs the most significant bit plane (FIG. 16).
(B) (represented by the MSB in (b)), is subjected to binary arithmetic coding, and is output as a bit stream. Next, the bit plane is lowered by one level, and similarly, each bit in the bit plane is subjected to binary arithmetic coding until the target bit plane reaches the least significant bit plane (represented by the LSB in FIG. 16B). Output to the output unit 1005. At this time,
The code of each quantization index is entropy-encoded immediately after the first non-zero bit is detected in the bit plane scan. In this entropy coding, the code length can be adjusted by appropriately terminating the coding in the middle.

Next, an image decoding apparatus for decoding a bit stream by the above-described image encoding apparatus will be described with reference to FIG.
7 will be described.

FIG. 17 is a block diagram showing a basic configuration of a conventional image decoding apparatus.

Reference numeral 1006 denotes a code input unit, 1007 denotes an entropy decoding unit, 1008 denotes an inverse quantization unit, 1009 denotes an inverse discrete wavelet transform unit, and 1010 denotes an image output unit.

The code input unit 1006 inputs a bit stream from the image coding apparatus, and outputs the input bit stream to the entropy decoding unit 1007. The entropy decoding unit 1007 decodes the input bit stream in bit plane units and outputs the result. One region of the sub-band to be decoded is sequentially decoded in bit plane units, and finally the quantization index is restored. The restored quantization index is output to the inverse quantization unit 1008, and is restored to the transform coefficient c 'by the following equation.

C ′ = Δ * q ′ / 2 ⁸ ; inside area (3) c ′ = Δ * q ′; outside area (4) where q ′ is a quantization index, Δ is a quantization step, and Δ Is the same value used at the time of encoding. c ′ is the restored transform coefficient. The transform coefficient c ′ is output to the subsequent inverse discrete wavelet transform unit 1009, subjected to inverse discrete wavelet transform, and restored to image data.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. <First Embodiment> FIG. 1 is a block diagram showing a configuration of an image processing apparatus according to a first embodiment of the present invention.

The first embodiment will be described as an image encoding apparatus.

In FIG. 1, 1 is an image input unit, 2 is a discrete wavelet transform unit, 3 is a quantization unit, 4 is an area designation unit, 5 is an entropy encoding unit, and 8 is a code output unit.
Reference numeral 6 denotes an interleave setting unit which determines the output order of bit plane encoded data and encodes the contents.
Reference numeral 7 denotes an interleave unit, and an interleave setting unit 6
A bit stream is constructed according to the output order output from.

In such a configuration, pixel signals included in an image signal to be encoded are input to the image input unit 1 in raster-scan order. The image signal output from the image input unit 1 is input to the discrete wavelet transform unit 2. The discrete wavelet transform unit 2 performs a two-dimensional discrete wavelet transform process on the input image signal, calculates and outputs a transform coefficient of each subband.
The output transform coefficient is output to the subsequent quantization unit 3.

The region specifying section 4 determines an ROI in an image signal to be encoded, and generates mask information indicating which transform coefficient belongs to the ROI when the target image is subjected to discrete wavelet transform. When the image including the ROI is subjected to the discrete wavelet transform,
The portion that the ROI occupies in each subband is calculated. Also,
The mask information is encoded and sent to the code output unit 8.

The mask information generated in this way is output to the quantization unit 3. The quantization unit 3 quantizes the input sub-band by a predetermined quantization step, and outputs a quantization index for the obtained quantization value. Next, the quantization unit 3 changes the quantization index according to the equations (1) and (2) based on the mask information input from the area specifying unit 4. Therefore, only the quantization index belonging to the ROI (spatial area) specified by the area specifying unit 4 is shifted up by 8 bits.

The process of shifting up the quantization index will be described with reference to FIG.

FIG. 2A shows a quantization index.
The center halftone dot indicates the ROI. FIG. 2B shows RO.
This shows a state in which the portion I is shifted up by 8 bits. FIG. 2 (c) shows a state in which 0 is supplemented in the dotted frame. Also, as the bit plane number, the highest order is set to 15 and the lowest order is set to 00. The quantization index shifted up in this way is output to the entropy encoding unit 5 that follows.

The entropy coding unit 5 decomposes the input quantization index into bit planes, performs binary arithmetic coding on a bit plane basis, and outputs a code stream for each bit plane.

The interleave setting unit 6 sets an output order for rearranging the encoded bit plane data. The interleave setting unit 6 inputs the predetermined output order of Table 1 below to the interleave unit 7.

[0053]

[Table 1]

The interleave setting unit 6 generates a bit plane number code for adding each bit plane number to the code stream of each bit plane, and inputs it to the code output unit 8.

The interleaver 7 outputs the code stream from the entropy coding unit 5 to the code output unit 8 according to the input output order. That is, first, the code stream of the most significant bit plane of the bit plane number 15 is selected and output to the code output unit 8. Subsequently, the code stream of the bit plane number 14 is selected and output to the code output unit 8. Thereafter, the code stream of the bit plane number specified according to Table 1 is selected and output to the code output unit 8. The code output unit 8 shapes each generated data according to a format and outputs final encoded data.

Here, the format of the encoded data will be described with reference to FIG.

The shaping of the encoded data will be described with reference to FIG. The code output unit 8 first outputs a header obtained by encoding information such as the size of an image. Subsequently, a BITS code representing the number of bits per pixel of the image data is output. Subsequently, encoded data of the mask information set by the area setting unit 4 is output. Hereinafter, encoded data of each subband is obtained. The sub-bands are LL, shown in FIG.
HL2, LH2, HH2, HL1, LH1, and HH1 are transmitted in this order. Each subband includes encoded data of each bit plane.

To explain using LL as an example, first, a BN code representing a bit plane number is output. In the case of Table 1 above, the BN code is bit plane number 15. Subsequently, the code stream of the bit plane number 15 encoded by the entropy encoding unit 5 is output.
Subsequently, a BN code having a value of 14 and a code stream of bit plane number 14 are output. Thereafter, the bit plane numbers 13, 12, 07, 06, 11, 10, 0
BN codes and code streams of 9, 05, 04, 08, 03, 02 and 01 follow, and finally bit plane number 0
A BN code of 0 and a code stream are output.

As described above, according to the first embodiment, it is possible to easily determine coded data that can appropriately reproduce not only the ROI but also the surrounding area by only slightly increasing the code amount.

In the first embodiment, the discrete wavelet transform is used as the orthogonal transform. However, the present invention is not limited to this, and other transforms may be used.

In the first embodiment, the interleaver 7
Is performed on the coded data, but the quantization result output from the quantization unit 3 may be interleaved and coded.

Although the amount of ROI shift-up has been described as 8 bits, it is of course possible to use the maximum number of bits of the quantization result.

Although the quantization section 3 is provided, it may be omitted depending on the application. <Embodiment 2> FIG. 4 is a block diagram showing the configuration of an image processing apparatus according to Embodiment 2 of the present invention.

The second embodiment will be described as an image decoding device.

In FIG. 4, reference numeral 51 denotes a code input unit; and 52, an interleave controller, which determines the input order of bit plane coded data and performs control for reconstructing a bit plane based on the determination result. Do. An interleaver 53 arranges bit streams according to the input order. 54 is an entropy decoding unit. An area setting unit 55 decodes the mask information and sets an ROI. 56 is an inverse quantization unit, 57 is an inverse discrete wavelet transform unit, and 58 is an image output unit.

In such a configuration, the code input unit 51
Inputs coded data. The input encoded data is encoded data according to the format of FIG. 3 of the first embodiment. The header and the BITS code are decoded from the input coded data so that they can be used in the subsequent processing. Also,
The encoded data of the mask information is input to the area setting unit 55, and the mask information is reproduced. Subsequently, of the encoded data of each bit plane, the BN code is input to the interleave controller 52, and the code stream is input to the interleaver 53.

The interleave controller 52 decodes the BN code and inputs it to the interleaver 53. The interleaver 53 arranges and stores the input code streams. For example, in the order of Table 1, the first code stream is encoded data of the 15th bit plane, the second code stream is encoded data of the 14th bit, and the third code stream is encoded data of the 13th bit. The encoded data, the fourth code stream is the encoded data of the 12th bit, the fifth code stream is the encoded data of the 7th bit, and thereafter, the input code streams are arranged and stored according to Table 1 above. . The aligned code stream is input to the entropy decoding unit 54.

The entropy decoding unit 54 decodes and outputs a code stream in bit plane units. One region of the sub-band to be decoded is sequentially decoded in bit plane units, and finally the quantization index is restored. The restored quantization index is output to the inverse quantization unit 56.

The inverse quantization unit 56 includes an entropy decoding unit 54
, The bit plane data decoded.

Here, regarding the configuration of the bit plane,
This will be described with reference to FIG.

FIG. 5A shows a state where up to the sixth bit plane has been input and decoded. Black thick frames represent the decoded bits, and the halftone dots are bits related to the ROI. Image restoration will be described by taking as an example a case where coded data is input up to the 6th bit plane due to communication line capacity or truncation on the coding side. The ROI is inversely quantized according to the equation (3) and shifted downward by 8 bits. The state at that time is shown in FIG. 5B, and the dotted-line bits in FIG. 5B indicate the value 0. The parts other than the ROI perform normal inverse quantization. Thus, the inverse quantization unit 56 reproduces the transform coefficient. Of course, the same operation is performed even when the entropy decoding is completed for all the bit planes.

The transform coefficients reproduced for all the sub-bands are output to the subsequent inverse discrete wavelet transform unit 57, where they are subjected to inverse transform, and the image data is restored. Then, the image data is output from the image output unit 58.

As described above, according to the second embodiment, not only the ROI portion but also the surrounding area can be suitably restored. Further, even if the decoding is interrupted in the middle, not only the ROI is displayed but also the surrounding area is reproduced at a minimum, so that the loss of information can be reduced.

In the second embodiment, the inverse discrete wavelet transform is used as the inverse orthogonal transform. However, the present invention is not limited to this, and another inverse transform may be used.

Further, in the second embodiment, the interleaving by the interleaver 53 is performed on the encoded data. However, the interleaving may be performed before the inverse quantization unit 56 to perform the inverse quantization. Absent.

Further, an inverse quantization unit 53 is provided.
It may be omitted depending on the application. <Embodiment 3> FIG. 6 is a block diagram showing a configuration of an image processing apparatus according to Embodiment 3 of the present invention.

The third embodiment is an image coding apparatus for performing intra-frame coding for independently coding each frame. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 6, reference numeral 101 denotes an interleaver, which selects a bit plane in accordance with an instruction from the interleaver 6. Reference numeral 102 denotes a rate control unit, which controls the information amount of each frame. Reference numeral 103 denotes an entropy coding unit, which can stop coding in response to a coding stop instruction from the rate control unit 102.

In the third embodiment, the image input unit 1 inputs image data of a moving image frame by frame. Hereinafter, a discrete wavelet transform unit 2, a quantization unit 3, and a region designation unit 4
Performs the same operation as in the first embodiment. That is, the input image data is subjected to a discrete wavelet transform, and the designated ROI is bit-shifted to a higher order to compensate for zero. The interleave setting device 6 outputs the output order according to Table 1, as in the first embodiment.

The interleave unit 101 selects a bit plane from the quantized data in the output order according to the instruction of the interleave setting unit 6, and
Enter 03. The entropy coding unit 103 performs binary arithmetic coding on the input bit planes and outputs a code stream to the code output unit 8 unless there is a coding stop instruction from the rate control unit 102. The code output unit 8
The generated data is shaped according to the format and the final encoded data is output.

Here, the format of the encoded data will be described with reference to FIG.

Referring to FIG. 7, the shaping of the encoded data will be described. The code output unit 8 first outputs a header obtained by encoding information such as the size of an image. Subsequently, a BITS code representing the number of bits per pixel of the image data is output. In the third embodiment, a portion where the value is not 0 in the 8th to 16th bits is defined as an ROI, and the same effect can be obtained without transmitting the mask information. Thereafter, encoded data of each bit plane is obtained.

The procedure for shaping the encoded data will be described.
First, a BN code representing a bit plane number is output. In the case of Table 1 above, bit plane number 15 B
N code. Subsequently, the code streams of the subbands of the bit plane number 15 encoded by the entropy encoding unit 5 are LL, HL2, LH2, HH2, HL1,
LH1 and HH1 are output in this order. Subsequently, the BN code of the bit plane number 14 and the code stream of each subband of the bit plane number 14 are output. Hereinafter, bit plane numbers 13, 12, 7, 6, 11, 10, 0
The BN code of 9, 05, 04, 08, 03, 02, 01 and the code stream of each sub-band are output, and finally the BN code of bit plane number 00 and the code stream of each sub-band are output. However, the rate control unit 102
Instructs the entropy coding unit 103 to stop coding, the output of the coded data of the frame at that time is ended, and the output of the coded data of the next frame is prepared.

The rate control unit 102 calculates the amount of code to be allocated to one frame from the frame rate of the input image data and the target bit rate for encoding. Then, the code amounts output from the code output unit 8 are added, and when the target bit rate per frame is exceeded, the entropy coding unit 103 is instructed to stop coding.

As described above, according to the third embodiment, it is possible to easily and accurately perform rate control on a moving image. Further, since the interleaver 101 performs interleaving based on the information input from the interleave setting unit 6, it is possible to generate coded data that can suitably transmit not only the ROI but also the surrounding area even if the rate becomes low.

In the above description, the amount of ROI shift up is set to 8 bits. However, the maximum number of bits of the quantization result may be used. <Embodiment 4> FIG. 8 is a block diagram showing a configuration of an image processing apparatus according to Embodiment 4 of the present invention.

The fourth embodiment is an image coding apparatus for performing intra-frame coding for independently coding each frame as in the third embodiment. The same components as those in the first and third embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 8, reference numeral 104 denotes an interleave setting device.

In the fourth embodiment, an image input unit 1, a discrete wavelet transform unit 2, a quantization unit 3, and a region designation unit 4
Performs the same operation as in the third embodiment. That is, the input image data is subjected to a discrete wavelet transform, and the designated ROI is bit-shifted to a higher order to compensate for zero.
The interleave setting unit 104 receives an encoding bit rate from the rate control unit 102 and selects either Table 1 or Table 2 below.

[0090]

[Table 2]

In the fourth embodiment, when the bit rate is low, the output order in Table 2 is selected, and when the bit rate is high, the output order in Table 1 is selected and output.

Thereafter, as in the third embodiment, the interleaver 101 selects a bit plane from the quantized data in the output order according to the instruction of the interleave setting unit 104 and inputs the bit plane to the entropy encoder 103. The entropy coding unit 103 performs binary arithmetic coding on the input bit planes and outputs a code stream to the code output unit 8 unless there is a coding stop instruction from the rate control unit 102. The code output unit 8 shapes each of the generated data according to a format and outputs encoded data.

As described above, according to the fourth embodiment, it is possible to easily and accurately perform rate control on a moving image. Since the interleaver 101 switches the interleaving method based on the bit rate based on the information input from the interleave setting unit 6, even if the rate becomes lower, the interleaver 101 transmits coded data that can preferably transmit not only the ROI but also the surrounding area. Can be generated. <Embodiment 5> FIG. 9 is a block diagram showing a configuration of an image processing apparatus according to Embodiment 5 of the present invention.

The fifth embodiment is an image encoding apparatus for encoding a still image as in the first embodiment.

In FIG. 9, reference numeral 500 denotes a central processing unit (C
PU) for controlling the entire image processing apparatus and performing various processes. Reference numeral 501 denotes a memory, which provides an operating system (OS) required for controlling the image processing apparatus, software, and a storage area required for calculation. Memory 501
An image area for controlling the entire image processing apparatus, storing an OS for operating various software and operating software, and reading the image area for encoding image data;
There is a code area for temporarily storing code data, and a working area for storing parameters for various operations and the like.

Reference numeral 502 denotes a bus for interconnecting various components constituting the image processing apparatus and transmitting and receiving data and control signals. 503, a storage device for storing software; and 504, a storage device for storing moving image data.
A monitor 505 displays an image. Reference numeral 508 denotes a communication line, which includes a LAN, a public line, a wireless line, a broadcast wave, and the like. Reference numeral 507 denotes a communication interface (I / F) for transmitting encoded data to the communication line 508. 5
Reference numeral 06 denotes a terminal, which is used for activating the image processing apparatus and setting various conditions such as a bit rate.

In such a configuration, prior to processing,
The terminal 506 selects moving image data to be encoded from the moving image data stored in the storage device 504, and instructs activation of the image processing apparatus. Then, the software stored in the storage device 503 is expanded in the memory 501 via the bus 502, and the software is activated.

Hereinafter, the storage device 504 by the CPU 500 will be described.
Encoding operation of moving image data stored in
This will be described with reference to FIG.

FIG. 10 is a flowchart showing an encoding operation according to the fifth embodiment of the present invention.

In step S1, the image data selected by the terminal 506 is read from the storage device 504, and
01 is stored in the image area. In step S2, the terminal 506 determines the ROI, and stores the area information in the memory 501.
In the working area. In step S3, the header and the BITS code shown in FIG.
1 is stored in the code area. Further, area information of the ROI is read from the working area, encoded as mask information, and subsequently stored in the code area.

In step S4, a discrete wavelet transform is performed on the image data stored in the image area of the memory 501 to obtain a transform coefficient. Step S5
Then, quantization is performed on the obtained transform coefficient, and the quantization result is stored in the image area. In step S6, RO
The quantization result of I is shifted up by 8 bits, and RO
Lower 8 bits of I and upper 8 in parts other than ROI
The bits are padded with zeros to generate a total of 16 bits of data.

In step S7, variables RO, RI, and N used in the subsequent loop are initialized. RO sets the value of the MSB of a valid bit plane outside the ROI, and RI sets the value of the MSB of a valid bit plane within the ROI. RO
Outside of I, it is originally 8 bits, so RO is 8,
Since 16 bits are shifted up in the ROI, 16 is set. Also, 0 is set to a variable N to be counted up.

In step S8, it is determined whether or not all bit planes have been processed, ie, whether RI = 8 and RO = 0. If RI = 8 and RO = 0 (YES in step S8), the flow advances to step S14 to store the contents of the code memory of the memory 501 in the storage device 504, and ends the processing. In step S14, the contents of the code memory may be transmitted to the communication line 508 via the communication interface 507.

If RI = 8 and RO = 0 are not satisfied (NO in step S8), the flow advances to step S9. In step S9, the content of the variable N is divided by 3 to determine whether the remainder is 0 or not. If the remainder is not 0 (N in step S9)
O), and proceed to step S10. On the other hand, when the remainder is 0 (YES in step S9), the process proceeds to step S11.

In step S10, it is determined whether or not RI = 8. If RI = 8 (YES in step S10), since the ROI has been encoded, the process proceeds to step S11 in order to encode a region outside the ROI.
In step S11, the value of RO is encoded and stored in the memory 50.
1 is stored in the code area. Subsequently, the bit plane indicated by the RO value is encoded by binary arithmetic encoding, and the generated encoded data is stored in the code area of the memory 501. Thereafter, 1 is subtracted from the value of RO, and the process proceeds to step S13.

On the other hand, if RI = 8 is not satisfied (step S1)
0 and NO), step S is performed to encode the ROI.
Proceed to 12. In step S12, the RI value is encoded and stored in the code area of the memory 501. Next, RI
Are encoded by binary arithmetic encoding, and the generated encoded data is stored in the code area of the memory 501. Thereafter, 1 is subtracted from the value of RI, and the process proceeds to step S13.

In the step S13, 1 is added to the contents of the variable N, and the process returns to the step S8.

As described above, according to the fifth embodiment, it is possible to generate a code with a good balance between the image quality inside and outside the ROI.

Although the amount of ROI shift up has been described as 8 bits, the maximum number of bits of the quantization result may of course be used. <Sixth Embodiment> The configuration of the image processing apparatus of the sixth embodiment is the same as the configuration of the image processing apparatus of the fifth embodiment shown in FIG. In the sixth embodiment, the decoding process of the encoded data generated in the fifth embodiment and stored in the storage device 504 will be described as an example.

In FIG. 9, prior to the processing, the terminal 506
Selects encoded data to be decoded from the encoded data stored in the storage device 504, and instructs activation of the image processing apparatus. Then, the software stored in the storage device 503 is expanded in the memory 501 via the bus 502, and the software is activated.

Hereinafter, the storage device 504 by the CPU 500 will be described.
Will be described with reference to FIG.

FIG. 11 is a flowchart showing a decoding operation according to the sixth embodiment of the present invention.

In step S51, the coded data selected by the terminal 506 is read from the storage device 504 and stored in the code area of the memory 501. In step S52, the header and the BITS code are decoded from the encoded data stored in the code area of the memory 501, and are stored in the working area so that they can be used in subsequent processing. The coded data of the mask information is decoded, the mask information is reproduced, and stored in the image area of the memory 501.

In step S53, it is determined whether decoding of all the input coded data has been completed or whether the terminal 506 has instructed to stop decoding. If the decoding of all the encoded data is completed or the decoding is interrupted (YES in step S53), the process proceeds to step S57. On the other hand, if the decoding of all the encoded data has not been completed or has not been interrupted (NO in step S53), the process proceeds to step S54.

In step S54, the coded data stored in the code area of the memory 501 is sequentially read, and
Decode the code and determine if its value is greater than eight. If the value is greater than 8 (YE in step S54)
S) The process proceeds to step S55 to decode the ROI. In step S55, the input bit plane (within the ROI) is decoded, stored in the bit plane indicated by the BN code value in the image area of the memory 501, and processed in the next bit plane. S53
Return to

On the other hand, when the value is 8 or less (step S
(NO at 54), the process proceeds to step S56. Step S56
Then, the input bit plane (outside the ROI) is decoded, stored in the bit plane indicated by the BN code value in the image area of the memory 501, and the process proceeds to step S53 to process the next bit plane. .

On the other hand, in step S57, it is assumed that decoding in bit plane units has been completed, and the bits of the ROI are shifted down according to the mask information of the image area in the memory 501 and stored in the image area. In step S58,
The quantization index of the image area is inversely quantized, and the obtained transform coefficient is stored in the image area. In step S59, the transform coefficients of the image area are subjected to inverse discrete wavelet transform to generate image data, and stored in the image area of the memory 501. In step S60, the restored image is displayed on the monitor 505, stored in the storage device 504,
The processing is terminated by sending the data to the communication line 508 via the communication interface 507. As described above, according to the sixth embodiment, it is possible to perform image restoration while appropriately maintaining the balance between the image quality inside and outside the ROI.

Although the amount of ROI shift-up is described as 8 bits, the maximum number of bits of the quantization result may of course be used.

In each of the above embodiments, Tables 1 and 2
, That is, the order of the interleaving of the bit planes is not limited to this, and can be changed for each frame of the moving image. Furthermore, if the order is fixed and it is clear that the order is the same in encoding and decoding, the BN code can be omitted.

The present invention can be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but it can be applied to a single device (for example, a copying machine, a facsimile machine). Etc.).

Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU)
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instructions of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the flowcharts shown in FIGS. 10 and 11 described above.

[0127]

As described above, according to the present invention,
It is possible to provide an image processing apparatus and method capable of suitably encoding and decoding an ROI and other areas, and a computer-readable memory.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a process of shifting up a quantization index according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a format of encoded data according to the first embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of an image processing apparatus according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration of a bit plane according to a second embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of an image processing device according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating a format of encoded data according to a third embodiment of the present invention.

FIG. 8 is a block diagram illustrating a configuration of an image processing apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of an image processing apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a flowchart illustrating an encoding operation according to the fifth embodiment of the present invention.

FIG. 11 is a flowchart illustrating a decoding operation according to the sixth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a basic configuration of a conventional image encoding device that realizes an ROI.

FIG. 13 is a diagram illustrating a configuration example of a subband of a two-level transform coefficient group obtained by a two-dimensional discrete wavelet transform process.

FIG. 14 is a diagram showing a process of generating mask information.

FIG. 15 is a diagram showing a process of shifting up a quantization index.

FIG. 16 is a diagram illustrating an operation of entropy encoding.

FIG. 17 is a block diagram illustrating a basic configuration of a conventional image decoding device.

FIG. 18 is a diagram for explaining a state of image deterioration due to conventional processing.

[Explanation of symbols]

 1,1001 Image input unit 2,1002 Discrete wavelet transform unit 3,1003 Quantization unit 4,1011 Area designation unit 5,103,1004 Entropy encoding unit 6,104 Interleave setting unit 7,53,101 Interleave unit 8,1005 Code output unit 51, 1006 Code input unit 52 Interleave controller 54, 1007 Entropy decoding unit 55 Area setting unit 56, 1008 Inverse quantization unit 57, 1009 Inverse discrete wavelet transform unit 58, 1010 Image output unit 102 Rate control unit 500 CPU 501 memory 502 bus 503, 504 storage device 505 monitor 506 terminal 507 communication interface 508 communication line

Continued on the front page F term (reference) 5B057 BA24 CA12 CA16 CB12 CB18 CC02 CG05 CH01 CH11 5C059 KK01 MA00 MA24 MA31 MB03 MB26 MD02 PP01 RB02 RB18 RC12 SS26 TA53 TB18 TC47 TD08 UA02 UA05 UA31 UA39 5C000 AA01 DB03 BA09 BA16 BA17 BC01 BC02 BC16 BC29 BD01 9A001 BB02 BB03 BB04 EE02 EE04 EE05 GG01 HH27 HH28 JJ20 KK56

Claims (18)

[Claims] 1. An image processing apparatus that encodes input image data, comprising: a determination unit that determines a high-quality coded area to be coded with higher quality than a surrounding area in the image data; A conversion means for performing an orthogonal transformation on the conversion data to generate conversion data; and converting the conversion data in the high-quality coding area to a higher bit to compensate for lower-order bits with zeros, thereby converting the conversion data outside the high-quality coding area. , A coding unit for coding each bit plane constituting the conversion data, and a designation for specifying an output order of each bit plane coded data obtained by the coding unit. And an output unit that outputs the bit-plane coded data based on the output order specified by the specifying unit. 2. The image processing apparatus according to claim 1, wherein the output unit includes a control unit that controls bit plane encoded data output from the encoding unit. 3. The image processing apparatus according to claim 1, further comprising a quantization unit that quantizes the transformed data. 4. The image processing apparatus according to claim 1, wherein the conversion unit performs a wavelet transform on the image data to generate the converted data. 5. An image processing apparatus for decoding input coded data, comprising: a bit-plane coding device having a high-quality coding region coded with higher quality than a surrounding region in an image; Input means for inputting encoded data including output-order encoded data specifying an output order of data; and storing each bit-plane encoded data constituting the encoded data based on the output-order encoded data. Storage means; bit shift means for performing a bit shift of the encoded data stored in the storage means; decoding means for decoding the encoded data bit-shifted by the bit shift means; and decoding means for decoding the encoded data. An image processing apparatus comprising: an inverse transform unit that performs inverse orthogonal transform on data to generate image data. 6. The image processing apparatus according to claim 5, wherein said bit shift means bit-shifts coded data corresponding to said high image quality area stored in said storage means to lower bits. 7. The image processing apparatus according to claim 5, further comprising: an inverse quantization unit that inversely quantizes the data decoded by the decoding unit. 8. The image processing apparatus according to claim 5, wherein the inverse transform unit performs inverse wavelet transform on the data decoded by the decoding unit to generate the image data. 9. An image processing method for encoding input image data, comprising: a determining step of determining a high-quality coded area to be coded at a higher quality than a surrounding area in the image data; Transforming the converted data in the high-quality coding area to a higher order and complementing the lower bits with 0, and performing conversion processing to generate converted data by performing orthogonal transformation on the converted data outside the high-quality coding area. A complementing step of supplementing 0 to upper bits of the encoding, an encoding step of encoding each bit plane constituting the conversion data, and a designation of designating an output order of each bit plane encoded data obtained in the encoding step. An image processing method, comprising: a step of: outputting the bit-plane coded data based on the output order specified in the specifying step. 10. The image processing method according to claim 9, wherein said output step includes a control step of controlling bit plane encoded data output from said encoding step. 11. The image processing method according to claim 9, further comprising a quantization step of quantizing the transformed data. 12. The image processing method according to claim 9, wherein said transforming step performs a wavelet transform on said image data to generate said transformed data. 13. An image processing method for decoding input coded data, wherein each bit plane coding includes a high quality coding area coded with higher quality than surrounding areas in the image. An input step of inputting encoded data including output-order encoded data specifying an output order of data; and a storage medium for storing each bit-plane encoded data constituting the encoded data based on the output-order encoded data. A bit shifting step of performing a bit shift of the encoded data stored in the storage medium in the storing step; and a decoding step of decoding the encoded data bit-shifted in the bit shifting step. An inverse transformation step of performing inverse orthogonal transformation on the data decoded in the decoding step to generate image data. 14. The image according to claim 13, wherein in the bit shifting step, the coded data corresponding to the high-quality area stored in the storage medium in the storing step is bit-shifted lower. Processing method. 15. The image processing method according to claim 13, further comprising: an inverse quantization step of inversely quantizing the data decoded in the decoding step. 16. The image processing method according to claim 13, wherein in the inverse transforming step, the image data is generated by performing an inverse wavelet transform on the data decoded in the decoding step. 17. A computer-readable memory storing a program code for image processing for encoding input image data, wherein a high-quality encoded area for encoding higher quality than a surrounding area in the image data is provided. A program code of a determining step of determining, a program code of a converting step of performing orthogonal transformation on the image data to generate converted data, and a bit shifting of the converted data in the high-quality coding area to a higher bit to a lower bit A program code of a compensation step of supplementing 0 and supplementing 0 to upper bits of the conversion data outside the high-quality coding area; and a program code of an encoding step of coding each bit plane constituting the conversion data. A program code of a designation step of designating an output order of each bit plane encoded data obtained in the encoding step; A program code for an output step of outputting the bit-plane encoded data based on the output order specified in the specifying step. 18. A computer-readable memory storing an image processing program code for decoding input encoded data, the computer-readable memory having a high-quality encoded area encoded at a higher quality than a surrounding area in the image. A program code of an input step of inputting coded data including output order coded data specifying an output order of each bit plane coded data to be configured; and the coded data based on the output order coded data. A program code of a storage step of storing each bit plane coded data constituting a storage medium in a storage medium; and a program code of a bit shift step of performing a bit shift of the coded data stored in the storage medium in the storage step. A program code of a decoding step of decoding the encoded data bit-shifted in the bit shifting step; A computer-readable memory characterized by comprising a program code for inverse conversion step of generating issue image data by applying an inverse orthogonal transformation to the data.