JPH08307814A - Image signal recording method and apparatus, image signal reproducing method and apparatus, and image signal recording medium - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to record / reproduce high resolution image signals while maintaining compatibility with the existing optical discs on which television signals are recorded. [Structure] A high-resolution image 201 is supplied to a high-resolution image encoder 200, subjected to motion compensation predictive coding, and a bit stream of the high-resolution image is formed. The 1/4 resolution image 101 is formed by passing the high resolution image through the down sampling circuit 301, and is compressed by the motion compensation predictive coding in the encoder 100. The decoded image generated for motion compensation by the encoder 100 is supplied to the encoder 200 via the upsampling circuit 302, and is used for encoding a high resolution image. Each bit stream is recorded on the first and second layers of the multilayer optical disc. When only the first layer is reproduced, an image similar to the current television image is obtained, and by reproducing the two layers at the same time, a high resolution image can be reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal encoding method and an image signal encoding method suitable for use in recording a moving image signal on a recording medium such as a magneto-optical disk and reproducing and displaying it. The present invention relates to an apparatus, an image signal decoding method, an image signal decoding apparatus, and an image signal recording medium.

[0002]

2. Description of the Related Art Devices for recording and reproducing current television signals and optical disks have been put into practical use. When such a moving image signal is recorded on a recording medium such as a magneto-optical disk and is reproduced and displayed on a display or the like, in order to use the recording medium efficiently, line correlation of the image signal or inter-frame The image signal is compressed and encoded by utilizing the correlation. For this compression encoding, ISO / IEC 13818-2, which is commonly called MPEG 2 established by ISO / IEC JTC-1 / SC29 WG11, is used. If the line correlation is used, the image signal, for example, D
It can be compressed by, for example, CT (discrete cosine transform) processing. Further, by using the inter-frame correlation, the image signal can be further compressed and encoded.

[0003]

As described above, the method of compressing and coding the current television signal as moving image data and recording the same on a recording medium such as an optical disc has been put into practical use. However, there is currently a demand for higher image quality, and H
There is a need for a DTV (High Definition Television) signal encoding / recording method. Further, since an optical disc in which the current television signal is encoded as moving image data has already been introduced to the market, compatibility with this optical disc is required.

Therefore, an object of the present invention is to efficiently generate coded data obtained by generating a prediction screen based on coded data of a current television signal and coding a high resolution moving image signal. An object is to provide an image signal recording method and apparatus capable of recording / reproducing, a reproducing method and apparatus, and an image signal recording medium.

Another object of the present invention is to provide an image signal recording method and apparatus and a reproducing method capable of achieving compatibility with an optical disc in which only the current television signals already on the market are recorded. And an apparatus, and an image signal recording medium.

[0006]

According to the present invention, a low resolution image signal and a high resolution image signal are generated in a method of recording an image signal on an optical disc having a plurality of information recording layers by utilizing compression coding. A step of compressing and encoding the low-resolution image signal to generate first encoded data; a step of recording the first encoded data on the first information recording layer of the optical disc; Generating a predicted image of the high-resolution image signal, compression-coding the high-resolution image signal using the predicted image to generate second coded data, and a step of generating a second coded data on the second information recording layer of the optical disc. And a step of recording encoded data. The present invention is also an apparatus for recording in this way.

Further, the present invention is an optical disc having a plurality of information recording layers, in which a low resolution image signal and a high resolution image signal are generated, and the first encoding is generated by compressing and encoding the low resolution image signal. Data is recorded in the first information recording layer, a predicted image of a high resolution image signal is generated from the low resolution image signal, and a second code generated by compressing and coding the high resolution image signal using the predicted image. Reproducing the first encoded data recorded in the first information recording layer from the optical disc in which the encoded data is recorded in the second information recording layer; and the step of reproducing the first encoded data recorded in the second information recording layer. And a step of reproducing a high resolution image signal by decoding the reproduced first and second encoded data in combination. It is a raw way. Further, the present invention is
This is a device for reproducing in this way.

Furthermore, the present invention is an optical disc having a plurality of information recording layers, in which a low-resolution image signal and a high-resolution image signal are generated, and the low-resolution image signal is compression-encoded to generate the first encoding. Data is recorded on the first information recording layer of the optical disc, a high-resolution image signal predicted image is generated from the low-resolution image signal, and the high-resolution image signal is compression-encoded using the predicted image to generate a second image. Is a disc-shaped recording medium in which the coded data of is recorded in the second information recording layer.

[0009]

By applying the present invention, the current television signal can be decoded by decoding only the bit stream from the information recording layer in which the current television signal is recorded. Further, a prediction screen is generated based on the first bit stream from the information recording layer in which the current television signal is recorded and this current television signal, and by using this, a high resolution moving image signal is generated. A high resolution moving image signal is decoded by combining and decoding the encoded second bit stream.

Furthermore, if the optical disc which has been recorded on the market and only the current television signal is recorded, and the layer on which the current television signal is recorded in the multilayer disc according to the present invention is the same, it is already marketed. Compatibility with existing optical discs in which only existing television signals are recorded.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Prior to the description of the present invention, an example of compression encoding of an image signal using inter-frame correlation will be described. For example, as shown in FIG.
At 1, t2, and t3, frame images PC1 and PC
2 and PC3 respectively, the difference between the image signals of the frame images PC1 and PC2 is calculated to generate PC12, and the difference between the frame images PC2 and PC3 is calculated to generate PC23. Generally in a continuous video,
Since the images of the temporally adjacent frames do not have such a large change, when the difference between them is calculated, the difference signal has a small value. Therefore, if this difference signal is encoded, the code amount can be compressed.

However, the original image cannot be decoded by transmitting only the difference signal. Therefore, the image of each frame is set to any one of three types of pictures of I picture, P picture, and B picture,
The image signal is compressed and encoded. FIG. 9 shows an example of processing when compression-encoding an image signal.

In FIG. 9, image signals of 17 frames F1 to F17 are set as a group of pictures, which is one unit of processing. Then, the image signal of the leading frame F1 is encoded as an I picture, the second frame F2 is processed as a B picture, and the third frame F3 is processed as a P picture. Hereinafter, the fourth and subsequent frames F4 to F17 are alternately processed as a B picture or a P picture.

As the image signal of the I picture, the image signal for one frame is encoded and transmitted as it is. On the other hand, as an image signal of a P picture, as shown in FIG. 9A, basically, a difference from an image signal of an I picture or a P picture that temporally precedes the encoded image is encoded and transmitted. To do. Further, as the image signal of the B picture, as shown in FIG. 9B, basically, as shown in FIG. 9B, a difference from the average value of both the temporally preceding frame and the subsequent frame is obtained, and the difference is encoded. Convert and transmit.

FIG. 10 shows the principle of the method of encoding a moving image signal in this way. As shown in the figure, since the first frame F1 is processed as an I picture, it is directly transmitted to the transmission path as the transmission data F1X (intra-frame coding). On the other hand, since the second frame F2 is processed as a B picture, the difference between the temporally preceding frame F1 and the temporally subsequent frame F3 average value is calculated, and the difference is calculated. It is transmitted as transmission data F2X.

The process for the B picture will be described in more detail. There are four types. The first process is to transmit the data of the original frame F2 as it is as the transmission data F2X (SP1) (intra coding), which is the same process as in the I picture. The second process is to calculate a difference from a frame F3 that is temporally following and transmit the difference (SP2) (backward predictive coding). The third process is to transmit a difference (SP3) from the temporally preceding frame F1 (forward predictive coding). Further, the fourth processing generates a difference (SP4) between the average value of the frame F1 preceding in time and the average value of the frame F3 following in time, and uses this as the transmission data F2.
It is transmitted as X (bidirectional predictive coding). Of these four methods, the method with the least amount of transmission data is adopted.

When transmitting the difference data, the motion vector x1 (frame F1) between the image of the current frame and the image (predicted image) of the frame for which the difference is to be calculated is transmitted.
Between F and F2) (for forward prediction) or x2 (motion vector between frames F3 and F2)
Either (for backward prediction) or both x1 and x2 (for bidirectional prediction) are transmitted with the difference data.

In the frame F3 of the P picture, the frame F1 temporally preceding is used as a predicted image to calculate a difference signal (SP3) from the frame and a motion vector x3, which is transmitted as transmission data F3X. (Forward predictive coding). Alternatively, the data of the original frame F3 is directly transmitted as the transmission data F3X (S
P1) (intra coding). As in the case of the B picture, whichever method is used for transmission is selected so that less transmission data is transmitted.

FIG. 11 shows an example of the configuration of an apparatus which encodes and transmits a moving image signal based on the above-mentioned principle, and decodes it. The encoding device 1 encodes the input video signal and transmits it to the recording medium 3 as a transmission path. Here, an optical disc is assumed as the recording medium 3. Then, the decoding device 2 reproduces the signal recorded on the recording medium 3, decodes the signal, and outputs the decoded signal.

In the encoding device 1, the input video signal is input to the pre-processing circuit 11, where the luminance signal and the chrominance signal (color difference signal in this example) are separated.
A / D conversion is performed by the / D converters 12 and 13. The video signal converted into a digital signal by A / D conversion by the A / D converters 12 and 13 is supplied to and stored in the frame memory 14. In the frame memory 14, the luminance signal is stored in the luminance signal frame memory 15, and the color difference signal is stored in the color difference signal frame memory 16.

The format conversion circuit 17 converts the frame format signal stored in the frame memory 14 into a block format signal. That is, FIG. 12A
As shown in FIG. 5, the video signal stored in the frame memory 14 is frame format data in which V lines of H dots are collected per line. The format conversion circuit 17 converts this 1-frame signal into 1
It is divided into N slices in units of 6 lines. Then, as shown in FIG. 12B, each slice is divided into M macroblocks. Each macroblock is 16x16
It is composed of luminance signals corresponding to individual pixels (dots). This luminance signal is further 8 × as shown in FIG. 12C.
The blocks are divided into blocks Y [1] to Y [4] in units of 8 dots. Then, the luminance signal of 16 × 16 dots includes a Cb signal of 8 × 8 dots and a Cr signal of 8 × 8 dots.
The signals are matched.

The signal thus converted into the block format is supplied from the format conversion circuit 17 to the encoder 18, where it is encoded. The details will be described later with reference to FIG.

The signal encoded by the encoder 18 is recorded as a bit stream on the recording medium 3, for example. Here, an optical disc is used as the recording medium 3.
The bitstream is recorded.

The data reproduced from the optical disk of the recording medium 3 is supplied to the decoder 31 of the decoding device 2 and decoded (decoded). Details of the decoder 31 will be described later with reference to FIG.

The data decoded by the decoder 31 is input to the format conversion circuit 32 and converted from a block format signal to a frame format signal. The luminance signal of the frame format is stored in the luminance signal frame memory 34 of the frame memory 33.
Are stored and stored in. Further, the color difference signal is supplied to and stored in the color difference signal frame memory 35. The luminance signal and the color difference signal read from the luminance signal frame memory 34 and the color difference signal frame memory 35 are respectively D / A converted by the D / A converters 36 and 37, supplied to the post-processing circuit 38, and combined. It Then, it is output and displayed on a display (not shown) such as a CRT.

Next, referring to FIG. 13, the encoder 18
An example of the configuration will be described. The image data to be encoded is the motion vector detection circuit 50 in macroblock units.
Is input to The motion vector detection circuit 50 processes the image data of each frame as an I picture, P picture, or B picture according to a predetermined sequence.
The images of each frame that are sequentially input are
As to which picture of P or B is to be processed, for example, as shown in FIG. 9, the group of pictures composed of the frames F1 to F17 is I, B, P,
It is predetermined to be processed as B, P, ... B, P.

The image data of a frame (for example, frame F1) processed as an I picture is transmitted from the motion vector detection circuit 50 to the front original image portion 51a of the frame memory 51.
The image data of the frame (for example, frame F2) that is transferred and stored in the reference original image section 51b is the image data of the frame (for example, frame F3) that is transferred and stored in the reference original image portion 51b. , And is transferred to and stored in the rear original image portion 51c.

At the next timing, B
When an image of a frame to be processed as a picture (frame F4) or P picture (frame F5) is input, the image data of the first P picture (frame F3) stored in the backward original image portion 51c until then is It is transferred to the front original image portion 51a, and the next B picture (frame F
The image data of 4) is stored (overwritten) in the reference original image portion 51b, and the image data of the next P picture (frame F5) is stored (overwritten) in the backward original image portion 51c. Such an operation is sequentially repeated.

The signal of each picture stored in the frame memory 51 is read therefrom, and the prediction mode switching circuit 52 performs frame prediction mode processing or field prediction mode processing. Furthermore, under the control of the prediction determination circuit 54, the calculation unit 53 performs calculation of intra-picture prediction, forward prediction, backward prediction, or bidirectional prediction. Which of these processes is to be performed is determined in accordance with the prediction error signal (difference between the reference image to be processed and the predicted image corresponding thereto). Therefore, the motion vector detection circuit 50 generates the sum of absolute values (or the sum of squares) of the prediction error signal used for this determination.

The frame prediction mode and field prediction mode in the prediction mode switching circuit 52 will be described.

When the frame prediction mode is set, the prediction mode switching circuit 52 supplies the four luminance blocks Y supplied from the motion vector detection circuit 50.
[1] to Y [4] are directly output to the arithmetic unit 53 in the subsequent stage. That is, in this case, as shown in FIG. 14A, the data of the odd field lines and the data of the even field lines are mixed in each luminance block. In this frame prediction mode,
Prediction is performed in units of four luminance blocks (macro blocks), and one motion vector corresponds to each of the four luminance blocks.

On the other hand, when the field prediction mode is set, the prediction mode switching circuit 52
14A shows the signal input from the motion vector detection circuit 50 in the configuration shown in FIG. 14A, as shown in FIG. 14B, among the four luminance blocks, luminance blocks Y [1] and Y [2].
Is composed of only the data of the lines of the odd field, and the other two luminance blocks Y [3] and Y [4] are
It is composed only of the data of the even field lines and is output to the arithmetic unit 53. In this case, one motion vector is associated with the two luminance blocks Y [1] and Y [2], and the other two luminance blocks Y [3] and Y [3].
Another motion vector is associated with [4].

The motion vector detection circuit 50 outputs the sum of absolute values of prediction errors in the frame prediction mode and the sum of absolute values of prediction errors in the field prediction mode to the prediction mode switching circuit 52. Prediction mode switching circuit 5
2 compares the sum of absolute values of prediction errors in the frame prediction mode and the field prediction mode, performs processing corresponding to the prediction mode having a smaller value, and calculates the data by the arithmetic unit 5.
Output to 3.

However, such processing is actually performed by the motion vector detection circuit 50. That is, the motion vector detection circuit 50 outputs a signal having a configuration corresponding to the determined mode to the prediction mode switching circuit 52, and the prediction mode switching circuit 52 outputs the signal as it is to the arithmetic unit 53 in the subsequent stage.

In the frame prediction mode, the color difference signal is supplied to the arithmetic unit 53 in a state where line data of odd fields and line data of even fields are mixed, as shown in FIG. 15A. Further, in the field prediction mode, as shown in FIG. 15B, the upper half four lines of each color difference block Cb, Cr are the luminance block Y.
Color difference signals of odd fields corresponding to [1] and Y [2], and the lower four lines are luminance blocks Y [3],
The color difference signal of the even field corresponding to Y [4] is used.

In addition, the motion vector detection circuit 50 uses the prediction determination circuit 54 to perform intra-picture prediction,
A sum of absolute values of prediction errors for determining whether to perform forward prediction, backward prediction, or bidirectional prediction is generated.

That is, the sum ΣAij of the signals Aij of the macroblocks of the reference image is used as the sum of the absolute values of the prediction errors of the intra-picture prediction.
The absolute value | ΣAij | of the macroblock and the sum Σ | Aij | of the absolute values | Aij | of the signal Aij of the macroblock are calculated. Also, as the sum of absolute values of prediction errors in forward prediction, the sum Σ | of the absolute value | Aij-Bij | of the difference Aij-Bij between the signal Aij of the macroblock of the reference image and the signal Bij of the macroblock of the predicted image.
Aij-Bij | is calculated. Further, the sum of absolute values of prediction errors between the backward prediction and the bidirectional prediction is also obtained in the same manner as in the case of forward prediction (changing the predicted image into a different predicted image from that in forward prediction).

The sum of these absolute values is supplied to the prediction judgment circuit 54. The prediction determination circuit 54 selects the smallest sum of absolute values of prediction errors of forward prediction, backward prediction, and bidirectional prediction as the sum of absolute values of prediction errors of inter prediction. Furthermore, the sum of absolute values of the prediction error of the inter prediction and the sum of absolute values of the prediction error of the intra-picture prediction are compared, the smaller one is selected, and the mode corresponding to the selected sum of absolute values is set as the prediction mode. select. That is, if the sum of absolute values of prediction errors in intra-picture prediction is smaller, the intra-picture prediction mode is set. If the sum of absolute values of prediction errors in inter prediction is smaller, the mode in which the corresponding sum of absolute values is the smallest is set among the forward prediction, backward prediction, and bidirectional prediction modes.

In this way, the motion vector detection circuit 50
Supplies the signal of the macroblock of the reference image to the arithmetic unit 53 via the prediction mode switching circuit 52 in a configuration corresponding to the mode selected by the prediction mode switching circuit 52 among the frame or field prediction modes. Of the four prediction modes, the prediction determination circuit 54
The motion vector between the prediction image and the reference image corresponding to the prediction mode selected by is detected, and this motion vector is output to the variable length coding circuit 58 and the motion compensation circuit 64.
As described above, the motion vector that minimizes the sum of absolute values of the corresponding prediction errors is selected.

The prediction determination circuit 54, when the motion vector detection circuit 50 is reading the image data of the I picture from the forward original image portion 51a, uses the intra-frame (image) prediction mode (the mode without motion compensation) as the prediction mode. ) Is set, and the switch 53d of the calculation unit 53 is switched to the contact a side. As a result, the image data of the I picture is DCT
It is input to the mode switching circuit 55.

As shown in FIG. 15A or B, this DCT mode switching circuit 55 is a state in which data of four luminance blocks are mixed with odd field lines and even field lines (frame DCT mode), or One of the separated states (field DCT mode) is output to the DCT circuit 56.

That is, the DCT mode switching circuit 55 is
Mixed data of odd field and even field D
Comparing the coding efficiency in the case of CT processing and the coding efficiency in the case of DCT processing in the separated state,
Select a mode with good coding efficiency.

For example, as shown in FIG. 15A, the input signal has a structure in which odd field lines and even field lines are mixed, and the difference between the signal of the odd field line and the signal of the even field line that are vertically adjacent to each other. Is calculated, and the sum (or sum of squares) of the absolute values is calculated.
In addition, as shown in FIG. 15B, the input signal has a configuration in which the lines of the odd field and the even field are separated, and the difference between the signals of the odd field lines vertically adjacent to each other and the signal of the line of the even field are Then, the sum of the absolute values (or the sum of squares) is calculated.
Further, both the sum of absolute values obtained by the data configuration of FIG. 15A and the sum of absolute values obtained by the data configuration of FIG. 15B are compared, and the DCT mode corresponding to a smaller value is set. That is, if the former is smaller, the frame DC
Set the T mode, and if the latter is smaller, set the field DCT mode.

Then, the data having the structure corresponding to the selected DCT mode is output to the DCT circuit 56, and the DCT flag indicating the selected DCT mode is output to the variable length coding circuit 58 and the motion compensation circuit 64.

The prediction mode in the prediction mode switching circuit 52 (FIG. 14) and the DCT mode switching circuit 5
As is clear by comparing the DCT mode in FIG. 5 (FIG. 15), the data structure in each mode is substantially the same for the luminance block.

When the frame prediction mode (a mode in which odd lines and even lines are mixed) is selected in the prediction mode switching circuit 52, the DCT mode switching circuit 55 is also in the frame DCT mode (odd lines and even lines are mixed). If the field prediction mode (a mode in which the data in the odd field and the data in the even field are separated) is selected in the prediction mode switching circuit 52, the field in the DCT mode switching circuit 55 is high. There is a high possibility that the DCT mode (mode in which the data of the odd field and the data of the even field are separated) is selected.

However, such a selection is not always made, and the prediction mode switching circuit 5
In 2, the mode is determined so that the sum of the absolute values of the prediction errors is small, and in the DCT mode switching circuit 55, the mode is determined so that the coding efficiency is good.

The I-picture image data output from the DCT mode switching circuit 55 is input to the DCT circuit 56, subjected to DCT (discrete cosine transform) processing, and converted into DCT coefficients. The DCT coefficient is input to the quantization circuit 57, quantized by a quantization scale corresponding to the data storage amount (buffer storage amount) of the transmission buffer 59, and then,
It is input to the variable length coding circuit 58.

The variable length coding circuit 58 is a quantization circuit 57.
The image data (in this case, I picture data) supplied from the quantization circuit 57 is converted into a variable-length code such as Huffman code corresponding to the supplied quantization scale, and is sent to the transmission buffer 59. Output.

The variable-length coding circuit 58 also determines whether the quantization scale is set by the quantization circuit 57 and the prediction mode (whether intra-picture prediction, forward prediction, backward prediction, or bidirectional prediction is set by the prediction determination circuit 54). Mode), a motion vector from the motion vector detection circuit 50, a prediction flag (a flag indicating whether the frame prediction mode or the field prediction mode has been set) from the prediction mode switching circuit 52, and the DCT output from the DCT mode switching circuit 55. A flag (a flag indicating whether the frame DCT mode or the field DCT mode is set) is input, and these are also variable length coded.

The transmission buffer 59 temporarily stores the input data and outputs the data corresponding to the storage amount to the quantization circuit 57. The transmission buffer 59 reduces the data amount of the quantized data by increasing the quantization scale of the quantization circuit 57 by the quantization control signal when the remaining data amount increases to the allowable upper limit value. On the contrary, when the data remaining amount decreases to the allowable lower limit value, the transmission buffer 59 reduces the quantization scale of the quantization circuit 57 by the quantization control signal to reduce the data amount of the quantized data. Increase. In this way, overflow or underflow of the transmission buffer 59 is prevented. Then, the data accumulated in the transmission buffer 59 is read out at a predetermined timing, output to the transmission path, and recorded in, for example, the recording medium 3.

On the other hand, the I picture data output from the quantization circuit 57 is input to the inverse quantization circuit 60 and inversely quantized in accordance with the quantization scale supplied from the quantization circuit 57. The output of the inverse quantization circuit 60 is IDCT
After being input to the (inverse DCT) circuit 61 and subjected to inverse DCT processing, it is supplied to and stored in the forward predicted image portion 63a of the frame memory 63 via the calculator 62.

When the motion vector detection circuit 50 processes the sequentially input image data of each frame as, for example, I, B, P, B, P, B ... Pictures, it is input first. After processing the image data of another frame as an I picture, before processing the image data of the next input frame as a B picture, the image data of the next input frame is processed as a P picture. This is because a B picture is accompanied by backward prediction and cannot be decoded unless a P picture as a backward predicted image is prepared in advance.

Then, the motion vector detection circuit 50 starts the processing of the image data of the P picture stored in the backward original image portion 51c after the processing of the I picture. Then, as in the case described above, the sum of absolute values of the inter-frame difference (prediction error) in macroblock units is supplied from the motion vector detection circuit 50 to the prediction mode switching circuit 52 and the prediction determination circuit 54. Prediction mode switching circuit 52
And the prediction determination circuit 54 sets the frame / field prediction mode, or the prediction mode of intra-picture prediction, forward prediction, backward prediction, or bidirectional prediction in accordance with the sum of the absolute values of the prediction errors of the macroblock of the P picture. To do.

When the intra-frame prediction mode is set, the arithmetic unit 53 switches the switch 53d to the contact a side as described above. Therefore, this data is similar to the I picture data in that the DCT mode switching circuit 55, the DCT
It is transmitted to the transmission line via the circuit 56, the quantization circuit 57, the variable length coding circuit 58, and the transmission buffer 59. Further, this data is supplied to and stored in the backward prediction image section 63b of the frame memory 63 via the inverse quantization circuit 60, the IDCT circuit 61, and the computing unit 62.

In the forward prediction mode, the switch 53d is switched to the contact b, and the image data (in this case, the I-picture image) stored in the forward prediction image portion 63a of the frame memory 63 is read out to move. The compensation circuit 64 compensates for the motion vector output from the motion vector detection circuit 50. That is, when the prediction determination circuit 54 instructs the motion compensation circuit 64 to set the forward prediction mode, the motion compensation circuit 64 sets the read address of the forward predicted image portion 63a to the position of the macroblock currently output by the motion vector detection circuit 50. Read data by shifting from the corresponding position by the amount corresponding to the motion vector,
Generate predicted image data.

The predicted image data output from the motion compensation circuit 64 is supplied to the calculator 53a. Calculator 53a
Subtracts the predicted image data corresponding to this macroblock supplied from the motion compensation circuit 64 from the data of the macroblock of the reference image supplied from the prediction mode switching circuit 52, and outputs the difference (prediction error). To do. This difference data is the DCT mode switching circuit 55, DC
T circuit 56, quantization circuit 57, variable length coding circuit 58,
It is transmitted to the transmission line via the transmission buffer 59. Also,
This difference data is stored in the inverse quantization circuit 60 and the IDCT circuit 6
It is locally decoded by 1 and input to the calculator 62.

The calculator 62 is also supplied with the same data as the predicted image data supplied to the calculator 53a. The calculator 62 adds the predicted image data output by the motion compensation circuit 64 to the difference data output by the IDCT circuit 61. As a result, the image data of the original (decoded) P picture is obtained. The image data of the P picture is supplied to and stored in the backward predicted image portion 63b of the frame memory 63.

In this way, the motion vector detection circuit 50 executes the processing of the B picture after the data of the I picture and the P picture are stored in the forward prediction image section 63a and the backward prediction image section 63b, respectively. The prediction mode switching circuit 52 and the prediction determination circuit 54 correspond to the magnitude of the sum of absolute values of inter-frame differences in macroblock units,
The frame / field mode is set, and the prediction mode is set to either the intra-frame prediction mode, the forward prediction mode, the backward prediction mode, or the bidirectional prediction mode.

As described above, the switch 53d is switched to the contact a or the contact b in the intra-frame prediction mode or the forward prediction mode. At this time, the same processing as in the P picture is performed and the data is transmitted.

On the other hand, when the backward prediction mode or the bidirectional prediction mode is set, the switch 53d is switched to the contact c or the contact d, respectively.

In the backward prediction mode in which the switch 53d is switched to the contact c, the image (in this case, P picture image) data stored in the backward predicted image section 63b is read out and the motion compensation circuit 64 is read. Thus, motion compensation is performed corresponding to the motion vector output by the motion vector detection circuit 50. That is, when the prediction determination circuit 54 instructs the motion compensation circuit 64 to set the backward prediction mode,
The read address of the backward predicted image portion 63b is shifted from the position corresponding to the position of the macro block currently output by the motion vector detection circuit 50 by the amount corresponding to the motion vector, and the data is read to generate predicted image data.

The predicted image data output from the motion compensation circuit 64 is supplied to the calculator 53b. Calculator 53b
Subtracts the predicted image data supplied from the motion compensation circuit 64 from the macroblock data of the reference image supplied from the prediction mode switching circuit 52, and outputs the difference. This difference data is stored in the DCT mode switching circuit 5
5, the DCT circuit 56, the quantization circuit 57, the variable length coding circuit 58, and the transmission buffer 59.

In the bidirectional prediction mode in which the switch 53d is switched to the contact point d, the image data (in this case, the I picture image) stored in the forward predicted image portion 63a and the backward predicted image portion 63b are stored. The image data (in this case, the image of the P picture) being read is read out, and the motion compensation circuit 64 causes the motion vector detection circuit 5
Motion compensation is performed according to the motion vector output by 0.
That is, the motion compensation circuit 64, when the bidirectional prediction mode setting is instructed by the prediction determination circuit 54, the motion vector detection circuit 50 now outputs the read addresses of the forward predicted image portion 63a and the backward predicted image portion 63b. The data is read out by shifting the amount corresponding to the motion vector (in this case, there are two for the forward prediction image and the backward prediction image) from the position corresponding to the position of the existing macroblock, and the prediction image data is generated. To do.

The predicted image data output from the motion compensation circuit 64 is supplied to the calculator 53c. Calculator 53c
Subtracts the average value of the predicted image data supplied from the motion compensation circuit 64 from the macroblock data of the reference image supplied from the motion vector detection circuit 50, and outputs the difference. This difference data is transmitted to the transmission line via the DCT mode switching circuit 55, the DCT circuit 56, the quantization circuit 57, the variable length coding circuit 58, and the transmission buffer 59. The B-picture image is not stored in the frame memory 63 because it is not used as a predicted image of another image.

In the frame memory 63, the forward predictive image portion 63a and the backward predictive image portion 63b are bank-switched as necessary, and a predetermined reference image
The one stored in one or the other can be switched and output as the forward prediction image or the backward prediction image.

In the above description, the luminance block is mainly described, but the chrominance block is similarly processed and transmitted in units of macro blocks shown in FIG. The motion vector used for processing the color difference block is obtained by halving the motion vector of the corresponding luminance block in each of the vertical direction and the horizontal direction.

Next, FIG. 16 shows a decoder 31 in FIG.
3 is a block diagram showing a configuration example of FIG. The encoded image data transmitted via the transmission path (recording medium 3) is received by a receiving circuit (not shown) or reproduced by a reproducing device.
After being temporarily stored in the reception buffer 81, it is supplied to the variable length decoding circuit 82. The variable length decoding circuit 82 performs variable length decoding on the data supplied from the reception buffer 81, the motion vector, the prediction mode, the prediction flag and the DCT flag to the motion compensation circuit 87, and the quantization scale to the dequantization circuit. And outputs the decoded image data to the inverse quantization circuit 83.

The inverse quantization circuit 83 is a variable length decoding circuit 8
The image data supplied from No. 2 is inversely quantized in accordance with the quantization scale supplied from the variable length decoding circuit 82 and output to the IDCT circuit 84. The data (DCT coefficient) output from the inverse quantization circuit 83 is the IDCT circuit 8
In step 4, inverse DCT processing is performed and the result is supplied to the calculator 85.

When the image data supplied from the IDCT circuit 84 is I-picture data, the data is output from the arithmetic unit 85 and input to the arithmetic unit 85 later (P or B-picture data). Is generated and supplied to the forward prediction image unit 86a of the frame memory 86 to be stored therein. Further, this data is output to the format conversion circuit 32 shown in FIG.

When the image data supplied from the IDCT circuit 84 is P picture data in which the image data one frame before is the predicted image data and is the data in the forward prediction mode, the forward prediction of the frame memory 86 is performed. The image data of one frame before (image data of I picture) stored in the image portion 86a is read out, and the motion compensation circuit 8
At 7, motion compensation corresponding to the motion vector output from the variable length decoding circuit 82 is performed. Then, in the calculator 85, the image data (difference data) supplied from the IDCT circuit 84 is added and output. The added data, that is, the decoded P picture data is
In order to generate predictive image data of image data (B-picture or P-picture data) input later to the calculator 85, it is supplied and stored in the backward predictive image section 86b of the frame memory 86.

Even in the case of P-picture data, the intra-prediction mode data is stored in the backward-predicted image section 86b as it is without any special processing by the calculator 85, like the I-picture data. Since this P picture is an image to be displayed next to the next B picture, it is not yet output to the format conversion circuit 32 at this point (as described above, the P picture input after the B picture is Processed and transmitted prior to B-pictures).

When the image data supplied from the IDCT circuit 84 is B picture data, it is stored in the forward predicted image portion 86a of the frame memory 86 in accordance with the prediction mode supplied from the variable length decoding circuit 82. Has been I
The image data of the picture (in the case of the forward prediction mode), the image data of the P picture stored in the backward prediction image portion 86b (in the case of the backward prediction mode), or both image data (in the case of bidirectional prediction mode) The motion compensation circuit 87 reads out and performs motion compensation corresponding to the motion vector output from the variable length decoding circuit 82,
A predicted image is generated. However, when motion compensation is not required (in the case of the intra-picture prediction mode), the predicted picture is not generated.

The data which has been motion-compensated by the motion compensation circuit 87 in this way is sent to the IDC in the calculator 85.
It is added to the output of the T circuit 84. This addition output is output to the format conversion circuit 32.

However, since this addition output is B picture data and is not used for generating a predicted image of another image, it is not stored in the frame memory 86.

After the B-picture image is output, the P-picture image data stored in the backward-predicted image portion 86b is read out, and the arithmetic unit 85 is passed through the motion compensation circuit 87.
Is supplied to. However, at this time, motion compensation is not performed.

The decoder 31 includes a prediction mode switching circuit 52 and a DC in the encoder 18 of FIG.
Although the circuits corresponding to the T mode switching circuit 55 are not shown, the processing corresponding to these circuits, that is, the configuration in which the signals of the lines of the odd field and the even field are separated is necessary for the original mixed configuration. The process of returning according to
The motion compensation circuit 87 executes this.

Further, although the processing of the luminance signal has been described above, the processing of the color difference signal is similarly performed.
However, in this case, the motion vector used for the luminance signal is halved in the vertical and horizontal directions.

The present invention hierarchically encodes the current television signal / HDTV signal by using the above-described method of compressing and encoding the existing television signal as moving image data and recording it on a recording medium such as an optical disk. To record.

First, the processing on the recording side according to the embodiment of the present invention will be described. FIG. 1 shows an outline of a hierarchical coding encoder provided on the recording side. A high resolution image 201 is prepared as an input image. This is 1/4 through the downsampling circuit 301 for hierarchical coding.
It is converted into a resolution image 101. 1/4 resolution image 10
1 is an image in which the number of pixels in the horizontal direction and the number of lines in the vertical direction are each half that of the high resolution image. The high resolution image 201 is generated by the HDTV signal,
A quarter resolution image is approximately equal to the standard resolution of current television signals.

In general down-sampling, a low-pass filter for band limitation in the horizontal and vertical directions is applied, and 2: 1 decimation is performed. The high resolution image signal is
The compression encoding encoder 200 for high resolution is supplied, and the ¼ resolution image 101 is supplied to the encoding encoding encoder 100 for ¼ resolution image. Bitstreams are output from the encoders 100 and 200 to output terminals 109 and 209, respectively. The ¼ resolution bit stream obtained at the output terminal 109 is recorded in the first information recording layer of the multilayer optical disc as described later, and the high resolution bit stream obtained at the output terminal 209 is the second information recording layer thereof. Recorded in.

The encoders 100 and 200 have the above-mentioned M
A PEG type can be used. In this example, the encoder 10 is used for prediction in the encoder 200.
A signal obtained by up-converting the prediction signal from 0 by the up-sampling circuit 302 is used. By doing so, the accuracy of prediction is improved.

FIG. 2 shows an encoder 1 for 1/4 resolution images.
An example of 00 is shown. The ¼ resolution image 101 obtained by the downsampling circuit 301 is input to the motion vector detection circuit 103. For the input image, a necessary image is read from the frame memory group 102 in macroblock units according to a preset image sequence (I picture, P picture, B picture), and the reference image and the forward original image and / or the backward original image are read. A motion vector is detected between the image and the image.

In-frame / forward / bidirectional prediction decision circuit 1
Reference numeral 04 determines the macroblock type of the reference block based on the sum of absolute values of inter-frame differences in block units calculated by the motion vector detection circuit. The prediction mode determined by the intra-frame / forward / bidirectional prediction determination circuit 104 is supplied to the variable length coding circuit 107.

Based on this macroblock type, intraframe / forward / bidirectional prediction is switched in block units. That is, the prediction determination circuit 104 outputs the input image itself in the intraframe coding mode, and
In the bidirectional prediction mode, the inter-frame coded data from each predicted image is output. Prediction determination circuit 104
The output signal of is supplied to the DCT circuit 105.

The DCT circuit 105 uses the two-dimensional correlation of the video signal to perform DCT conversion on the input image data or the difference data in block units, and the resulting converted data (D
The CT coefficient) is supplied to the quantization circuit 106. The quantization circuit 106 quantizes the DCT transform data with a quantization step size determined for each macroblock and slice,
The resulting quantized data is variable length coded (VL
C) Supply to the circuit 107 and the inverse quantization circuit 110.
The quantization scale used for quantization is the transmission buffer memory 1
By feeding back the remaining buffer capacity of 08, the transmission buffer memory 108 determines a value that does not cause overflow / underflow. This quantization scale is also the variable length coding circuit 107 and the dequantization circuit 110.
Is supplied with the quantized data.

Here, the VLC circuit 107 performs variable length coding processing on the quantized data together with the quantization scale, macroblock type, and motion vector, and supplies it to the transmission buffer memory 108 as transmission data. The 1/4 resolution image bit stream extracted from the transmission buffer memory 108 to the output terminal 109 includes encoded data of a macroblock, a prediction mode, a motion vector, and a DCT coefficient.

The inverse quantization circuit 110 is used by the quantization circuit 106.
The quantized data sent from the device is converted into a representative value, that is, inverse quantized data, and the converted data of the output data before conversion in the quantization circuit 106 is decoded. This inverse quantized data is IDCT (inverse discrete cosine trasform)
It is supplied to the circuit 111. The IDCT circuit 111 converts the dequantized data decoded by the dequantization circuit 110 into decoded image data by a conversion process reverse to that of the DCT circuit 105,
It is output to the frame memory 112.

The motion compensation circuit 113 includes the IDCT circuit 11
Local decoding is performed using the output data of 1, the macroblock type, the motion vector, the frame / field prediction flag, and the frame / field DCT flag, and the decoded image is written in the frame memory group 112 as a forward prediction image or a backward prediction image. Frame memory group 112
Then, bank switching is performed. As a result, a single frame is output as a backward prediction image or a forward prediction image depending on the image to be encoded. In the case of forward / bidirectional prediction, since the difference from the predicted image is sent as the output of the IDCT circuit 111,
Local decoding is performed by adding this difference to the predicted image. This predicted image is exactly the same as the image decoded by the decoder, and the next processed image performs forward / bidirectional prediction based on this predicted image.

Further, the locally decoded predicted image is supplied to the high resolution image encoder 200 via the upsampling circuit 302.

FIG. 3 shows an encoder 20 for high resolution images.
The structure of 0 is shown. This encoder 200 has the above-mentioned 1
The processes other than the prediction are the same as those of the encoder 100 for the / 4 resolution image. The high resolution image 201 is supplied to the prediction determination circuit 204 via the motion vector detection circuit 203. This circuit performs intra-frame coding, forward / bidirectional prediction by motion compensation from the frame memory 212, and prediction from a 1/4 resolution image.

IDC in encoding 1/4 resolution image
The image data output from the addition circuit on the output side of the T circuit 111 is interpolated by the upsampling circuit 302 to have the same resolution as that of the high resolution image. In general upsampling, the number of pixels can be doubled in the horizontal and vertical directions by using the average value of pixels adjacent to the interpolation pixel as the interpolation value. The interpolated image generated in this way is output from the upsampling circuit 302 and supplied to the prediction determination circuit 204 via the weighting circuit 303. In the weighting circuit 303, the weight (1-
W) is multiplied. The output of the weighting circuit 303 is the first predicted image.

On the other hand, from the motion compensation circuit 213,
The predictive image is provided by bidirectional motion compensation. A weighting circuit 305 multiplies the predicted image by a weight W. The output of the weighting circuit 303 is the second predicted image.

The first and second predicted images are added by the arithmetic unit 304 to form a third predicted image. The prediction determination circuit 204 makes a prediction using the third predicted image. The weight W is set to the weight determination circuit 3 so that the prediction efficiency of the third predicted image is maximized.
It will be decided at 06. At the same time, this weight is supplied to the variable length coding circuit 207 and coded and transmitted.

The prediction determination circuit 204 can obtain higher prediction efficiency by using the 1/4 resolution image in addition to the conventional motion compensation. For example, between the high resolution image and the 1/4 resolution image, the difference can be set to almost 0 for the pixels at the same position. This hierarchical coding can improve the compression efficiency. The determined prediction mode is supplied to the variable length coding circuit 207 and coded and transmitted. Further, this prediction data is supplied to the DCT circuit 205. The other processing is the same as that of the encoder 100 for the 1/4 resolution image. The bit stream extracted at the output terminal 209 of the transmission buffer 208 includes the encoded data of the macroblock, the prediction mode, the motion vector, and the weight W.

The bit streams taken out at the output terminals 109 and 209 are recorded in the respective information recording layers of the multi-layer optical disc. FIG. 4 shows a single-layer optical disc 701 having a single information recording layer 702 and an optical pickup 70.
3 shows a method of recording and reading. This is used in the current system, and when simply recording the image signal of the current television system, recording and reading are performed by this system.

On the other hand, in FIG. 5, the first information recording layer 705 and the second information recording layer 706 are provided in the thickness direction of the disc, and the optical pickup 70 is provided from one side.
7 shows a single-sided dual-layer type disc 704 in which information is recorded and read by means of a recording medium 708. As described above, the bit stream of the 1/4 resolution image is transferred to the single-sided dual-layer disc 704.
, And the bit stream of the high resolution image is recorded in the second layer 706.

As a result, the conventional single-layer optical disk 7
In the case of a reproducing apparatus capable of reproducing 01, the current television signal is decoded by reading and decoding only the first layer 705. In addition, both information recording layers 705,
A high resolution image signal can be reproduced by simultaneously reading 706 by the optical pickups 707 and 708, and combining and decoding as will be described later. With this method, compatibility with a single-layer disc can be realized.

FIG. 6 shows a double-sided bonded optical disc 709 having information recording layers 710 and 711 on both sides. When the recording layer 710 on the front surface is the first layer and the recording layer 711 on the back surface is the second layer, an optical pickup 712 for recording and reading is provided for the first layer 710, and for the second layer 711. An optical pickup 713 for recording and reading is provided. In this case, one side 2
Similar to the layered optical disc 704, the bit stream of the 1/4 resolution image is recorded on the first layer 710. Further, by recording the bit stream of the high resolution image in the second layer 711, it is possible to achieve the effect that the high resolution image signal can be reproduced while maintaining compatibility.

Next, the decoder provided on the reproducing side will be described. FIG. 7 shows a block diagram of a decoder when hierarchical coding is performed. A bit stream of a 1/4 resolution image reproduced from the first layer of the multilayer optical disc is supplied to the input terminal indicated by 401. This bit stream is decoded in the conventional manner.

The bit stream from the input terminal 401 is variable length decoded (IVLC) via the reception buffer 402.
It is input to the circuit 403. The variable length decoding circuit 403
Quantized data from the bitstream, motion vectors,
Decode macroblock type, quantization scale, frame / field prediction flag, frame / field DCT flag. This quantized data and quantization scale are
It is input to the next inverse quantization circuit 404.

Inverse quantization circuit 404, IDCT circuit 40
5. The operation of the motion compensation circuit 407 is similar to the local decoding operation of the encoder shown in FIG. With these circuits, a 1/4 resolution image signal 408 is obtained. at the same time,
The decoded image is stored in the frame memory 4 for prediction of the next image.
It is stored in 06.

On the other hand, the image stored in the frame memory 406 is supplied to the high resolution image decoder for use in decoding (predicting) the high resolution image. That is, the decoded ¼ resolution image is supplied to the weighting circuit 603 via the upsampling circuit 602, and the weighting circuit 603 multiplies the weight by (1−W). The output image of the weighting circuit 603 is the first predicted image for the high resolution decoder.

A high resolution bit stream reproduced from the second layer of the multi-layer optical disc is input from the input terminal 501 to the high resolution image decoder. This bit stream is input to the variable length decoding (IVLC) circuit 503 via the reception buffer 502. Then, the inverse quantization circuit 504, the IDCT circuit 505, and the motion compensation circuit 50
7, the high resolution image 508 is decoded. at the same time,
The decoded image is stored in the frame memory 506 for prediction of the next image.

Here, the output from the motion compensation circuit 507 is supplied to the weighting circuit 604, and the weighting circuit 60.
A second predicted image is formed by 4. The second predictive image and the first predictive image formed from the 1/4 resolution image are added by the calculator 605. The output of the calculator 605 is used as a prediction image for the high resolution decoder. The weight W used here is the weight W used in the encoder, and is obtained from the IVLC circuit 503 after decoding the bitstream. The decoding of the high resolution image is completed by the above process.

As the recordable / reproducible optical disc, an MO (magneto-optical) disc, a PD capable of recording many times is used.
(Phase change type) disc and WO that can record once
You can use a disc. Furthermore, when considering only reproduction, a ROM type optical disk can be used. Furthermore, it is also possible to use a single-sided recording / reading optical disc which is a lamination type in which two single-layer discs are laminated with a transparent adhesive material.

[0107]

According to the present invention, a standard-resolution image signal is compression-encoded and recorded on the first layer of a multi-layer optical disk, and a high-resolution image signal is also recorded on the second layer of the predicted image of the standard-resolution image signal. It is used for compression coding and recorded. Therefore, according to the present invention, a high resolution moving image signal can be efficiently recorded.

Furthermore, if the optical disc for recording only the current television signal already on the market and the layer for recording the television signal of standard resolution in the multi-layer disc according to the present invention are configured to be the same, Compatibility with an optical disc in which only television signals are recorded is realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a recording circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram of an example of a 1/4 resolution image signal encoder in a recording circuit according to an embodiment of the present invention.

FIG. 3 is a block diagram of an example of an encoder for high resolution image signals in a recording circuit according to an embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a method of recording and reading a single-layer disc.

FIG. 5 is a schematic diagram illustrating a method for recording and reading a single-sided, dual-layer optical disc.

FIG. 6 is a schematic diagram illustrating a method of recording and reading a disc having a front surface and a back surface bonded to each other.

FIG. 7 is a block diagram showing a configuration of a reproducing circuit according to an embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating the principle of high efficiency encoding that can be used in the present invention.

FIG. 9 is a schematic diagram illustrating a type of picture when image data is compressed.

FIG. 10 is a schematic diagram illustrating the principle of encoding a moving image signal.

FIG. 11 is a block diagram showing a configuration example of an image signal encoding device and a decoding device proposed previously.

12 is a diagram for explaining the format conversion operation of the format conversion circuit in FIG.

13 is a block diagram showing a configuration example of an encoder in FIG.

14 is a schematic diagram illustrating the operation of the prediction mode switching circuit in FIG.

15 is a schematic diagram illustrating the operation of the DCT mode switching circuit 55 in FIG.

16 is a block diagram illustrating a configuration example of a decoder 31 of FIG.

[Explanation of symbols]

 101 1/4 resolution image 105 DCT circuit 106 Quantization circuit 107 Variable length coding circuit 108 Transmission buffer 109 1/4 resolution image bit stream 201 High resolution image 205 DCT circuit 206 Quantization circuit 207 Variable length coding circuit 208 Transmission Buffer 209 High-resolution image bit stream 301 Down-sampling circuit 302 Up-sampling circuit 303 Weighting circuit 305 Weighting circuit 306 Weight determination circuit 401 1 / 4-resolution bit stream 402 Reception buffer 408 1 / 4-resolution image 501 High-resolution bit stream 502 Reception buffer 508 High-resolution image 602 Upsampling circuit 603 Weighting circuit 604 Weighting circuit

Claims (15)

[Claims] 1. A method of recording an image signal on an optical disc having a plurality of information recording layers by using compression encoding, a step of generating a low resolution image signal and a high resolution image signal, and the low resolution image signal. Compressing and encoding the first encoded data to generate the first encoded data, recording the first encoded data on the first information recording layer of the optical disc, and converting the low resolution image signal to the high resolution image. Generating a predicted image of a signal, compressing and coding the high resolution image signal using the predicted image to generate second coded data, and the second information recording layer on the second information recording layer of the optical disc. And a step of recording the encoded data of 1., the image signal recording method. 2. An optical disc having a plurality of information recording layers, wherein a low resolution image signal and a high resolution image signal are generated, and first encoded data generated by compression encoding the low resolution image signal is first. A second image recorded in one information recording layer, which is generated by generating a predicted image of the high resolution image signal from the low resolution image signal and compressing and coding the high resolution image signal using the predicted image. A step of reproducing the first coded data recorded on the first information recording layer from the optical disc having the coded data recorded on the second information recording layer; and recording the first coded data on the second information recording layer. And reproducing the high-resolution image signal by combining and decoding the reproduced first and second encoded data. Image signal reproducing method, wherein a. 3. An optical disc having a plurality of information recording layers, wherein a low-resolution image signal and a high-resolution image signal are generated, and the first encoded data generated by compression-encoding the low-resolution image signal is the above-mentioned. It is recorded on the first information recording layer of the optical disc and is generated by generating a predicted image of the high resolution image signal from the low resolution image signal and compressing and coding the high resolution image signal using the predicted image. A disc-shaped recording medium, characterized in that the second encoded data is recorded in the second information recording layer. 4. An apparatus for recording an image signal on an optical disc having a plurality of information recording layers by using compression encoding, means for generating a low resolution image signal and a high resolution image signal, and the low resolution image signal. Means for compressing and encoding the first encoded data to generate first encoded data, means for recording the first encoded data in the first information recording layer of the optical disc, and the high resolution image from the low resolution image signal. Means for generating a predicted image of a signal, compression-coding the high-resolution image signal using the predicted image to generate second coded data, and the second information recording layer on the second information recording layer of the optical disc. And a means for recording the encoded data of 1. 5. An optical disc having a plurality of information recording layers, wherein a low resolution image signal and a high resolution image signal are generated, and first encoded data generated by compression encoding the low resolution image signal is first. A second image recorded on one information recording layer, which is generated by generating a predicted image of the high resolution image signal from the low resolution image signal and compressing and coding the high resolution image signal using the predicted image. Means for reproducing the first coded data recorded on the first information recording layer from an optical disc having the coded data recorded on the second information recording layer; and a means for reproducing the first coded data recorded on the second information recording layer. And reproducing the high-resolution image signal by combining and decoding the reproduced first and second encoded data. Image signal reproducing apparatus for. 6. The image signal recording method according to claim 1, wherein the optical disc is a single-sided multi-layer disc. 7. The image signal reproducing method according to claim 2, wherein the optical disc is a single-sided multi-layer disc. 8. The disc-shaped recording medium according to claim 3, wherein the optical disc is a single-sided multi-layer disc. 9. The image signal recording apparatus according to claim 4, wherein the optical disc is a single-sided multi-layer disc. 10. The image signal reproducing apparatus according to claim 5, wherein the optical disc is a single-sided multi-layer disc. 11. The image signal recording method according to claim 1, wherein the optical disc is a laminated double-sided disc. 12. The image signal reproducing method according to claim 2, wherein the optical disc is a laminated double-sided disc. 13. The disc-shaped recording medium according to claim 3, wherein the optical disc is a laminated double-sided disc. 14. The image signal recording apparatus according to claim 4, wherein the optical disk is a laminated double-sided disk. 15. The image signal reproducing apparatus according to claim 5, wherein the optical disk is a laminated double-sided disk.