JP2000069485A - Moving picture compression device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moving picture compression device in which the number of frames that are actually compressed can be reduced and smooth movement can be realized without deteriorating picture quality. SOLUTION: A movement retrieval means 12 obtains with which part in a reference frame the respective blocks of a present frame has high correlation. A distance to the block having the highest correlation is set to be the moving distance of the block from the reference frame. A movement judgment means 13 obtains the total of moving quantity in a whole screen based on the moving distances of the respective blocks and judges whether the present frame is a picture having movement or not. When the present frame is judged to be a picture with less movement, a processing up to the movement judgment means 13 is executed by the previously decided number of frames. Then, the compression processings of a frequency conversion means 14 and subsequent means are executed after the number of frames exceeds the previously decided number. When the picture of much movement is detected in the movement judgement means even if the number of frames does not continuously satisfy the previously decided number, the compression processing is executed without a system waits for the previously decided number of frames.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving image compression apparatus for compressing and encoding a moving image and recording the moving image on, for example, a storage medium.
When there is a lot of movement, compression can be performed with smoothness.

[0002]

2. Description of the Related Art As one of moving image compression methods for communication systems, there is a method of obtaining and compressing only a portion that has changed compared to a previous frame. According to this method, in the case of a rapidly moving image, there are many changed parts and the compression efficiency is reduced.
When transmitting an image in real time through a network or the like, if the compression efficiency is reduced, it takes time to transmit, and the number of frames that can be transmitted is reduced. Even if a compressed image is recorded on a storage medium instead of being transmitted in real time by the same compression method, the processing operation does not change, so that the number of frames is reduced in a portion having a lot of motion.

Also, MPEG (Moving Picture Experts)
In a moving image compression method of a storage system represented by Group 1, the number of frames per unit time is determined. Therefore, it is necessary to compress a portion having a small amount of motion or a portion having a large amount of motion at a constant sampling cycle. is there. With this method, an image that does not change much in appearance must also be compressed, so that the compression efficiency is reduced.

Japanese Patent Application Laid-Open No. 7-75092 discloses that
A method is described in which the compression rate is adjusted by changing the resolution according to the amount of data that can be sent over a network. This method has a problem that the image quality is degraded because the resolution of a portion having a lot of motion is reduced depending on the state of the network.

Japanese Patent Laid-Open Publication No. Hei 7-222173 describes a method of calculating a difference between frames and transmitting an identification signal indicating a still state without transmitting an image with little motion. This method has a problem that a dedicated decoder for judging the identification signal is required. When it is determined that the still data is still, the transmission of the image data is shortened. Therefore, there is also a problem that the bandwidth of the transmission path cannot be fully utilized.

[0006]

An object of the present invention is to reduce the number of frames to be actually compressed,
It is an object of the present invention to provide a moving image compression apparatus capable of reproducing smooth motion without deteriorating image quality.

[0007]

The basic structure of a moving picture compression apparatus according to the present invention is as follows. A motion search means for receiving moving picture data on a frame basis and detecting how much the picture has changed from the previous frame, Motion determining means for determining whether or not the current frame is a moving image based on the total of the entire screen of the determined amount. If the result of the determination is that the image has little motion, a predetermined one-seventh frame is used. Compression means for compressing only frames and, when it is determined that there is a lot of motion, compressing several consecutive frames.

A moving picture compression apparatus according to a first embodiment, which embodies this basic configuration, receives moving picture data in frame units, divides the current frame into a plurality of blocks, and each block has a correlation with any part of the reference frame. Motion search means for determining whether the distance is high or not, and using a distance to a block having the highest correlation as a moving distance of the block from the reference frame;
The difference between the motion determining means for determining whether the current frame is a moving image by calculating the sum of the moving amounts of the entire screen based on the moving distance of each block, and the highly correlated block obtained by the motion searching means Frequency conversion means for converting data into frequency components, a quantization means for quantizing the data after the conversion, and a variable length coding means for performing variable length coding on the quantized data, If the current frame is an image with little motion, only the processing up to the motion determining means is performed up to the predetermined number of frames, and after that, the processing after the frequency converting means is performed, and the processing is performed to the predetermined number of frames. If an image with a lot of motion is detected by the motion judging means within less than consecutive times, the processing after the frequency converting means is performed without waiting for a predetermined number of frames.

A moving image compression apparatus according to a second aspect receives moving image data on a frame basis, divides a current frame into a plurality of blocks, determines which part of a reference frame has a high correlation with each block, and determines the highest correlation. Search means that sets the distance to the block with the highest frame as the moving distance of the block from the reference frame, and determines whether the current frame is a moving image by calculating the total moving amount of the entire screen based on the moving distance of each block. Motion determining means for determining whether or not the difference data between the highly correlated block obtained by the motion searching means is converted into frequency components; quantizing means for quantizing the converted data; Variable length coding means for performing variable length coding of the encoded data, and data clear means for setting the difference data value to 0, wherein the current frame is determined by the motion determining means. In the case of an image with a small amount of motion, the difference data value from the previous frame is set to 0 by the data clear unit until the number of frames reaches a predetermined number, and the compressed code is set by the variable length coding unit. If an image with a lot of motion is detected by the motion determining means within less than the predetermined number of frames consecutively, the processing after the frequency conversion means is performed without waiting for the predetermined number of frames. Do.

A moving image compression apparatus according to a third aspect is provided with a difference detecting means for calculating a difference between an input current frame and a reference frame, and a total sum of the magnitudes of the difference values over the entire screen based on the difference values of each pixel. And a motion determining means for determining whether the current frame is a moving image, and dividing the current frame into a plurality of blocks to determine which part of the reference frame has a high correlation with each block, and Motion search means for extracting difference data from the block, frequency conversion means for converting difference data from the highly correlated block into frequency components, quantization means for quantizing the converted data, and quantization data A variable-length encoding unit for performing variable-length encoding. If the current frame is an image with little motion as judged by the motion judging unit, a motion judging method is performed up to a predetermined number of frames. Only the processing up to and including the motion search means are performed after that, and if an image with a lot of motion is detected by the motion determination means within less than the predetermined number of frames continuously, The processing after the motion search means is performed without waiting for the determined number of frames.

In any of the first to third aspects, an inverse quantization means for inversely quantizing a result of the quantization means,
It is possible to add an inverse frequency conversion means for converting the frequency component into a pixel component and a motion compensation means for creating a reference frame for the motion search means from the converted data.

[0012]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a moving image compression apparatus according to a first embodiment of the present invention includes an image input unit 11 and a motion search unit 1.
2, motion determining means 13, frequency converting means 14, quantizing means 15, dequantizing means 16, inverse frequency converting means 17, motion compensating means 18, variable length coding means 19
And output means 20.

Each of these means operates as follows. An image is input in units of one frame from the image input unit 11, and the motion search unit 12 divides the current frame into a plurality of blocks in order to determine the correlation between the previous frame stored as a reference frame and the current frame. Find out which part of the reference frame the block is highly correlated with. The distance to the block with the highest correlation is considered as the movement distance of the block from the reference frame. The motion judging means 13 calculates the total sum of the moving amounts of the entire screen based on the moving distance of each block, and from this value, it is possible to know how much the current frame has changed from the reference frame.

If the current frame is an image with a lot of motion, difference data from a highly correlated block obtained by the motion search means 12 is input to the frequency conversion means 14. The difference data is converted into a frequency component by the frequency conversion unit 14, and quantization is performed by the quantization unit 15. The data is converted into a compression code by the variable length coding means 19 and output by the output means 20. In order to create a reference frame for the next frame compression, quantization means 1 is used.
The result of No. 5 is passed to the inverse quantization means 16 for inverse quantization, the frequency component is converted to the pixel component by the inverse frequency conversion means 17, and the data of the reference frame is created by the motion compensation means 18.

If the current frame is an image with little motion,
If the number of frames is less than a predetermined number of frames, for example, 10 continuous frames, only the processing up to the motion determining means 13 is performed, and all the processing after the frequency converting means 14 is performed on the eleventh frame. If an image with a lot of motion is detected by the motion determining means 13 within less than 10 consecutive frames, 1
The processing after the frequency conversion means 14 is performed without waiting for the first frame.

Next, the overall operation of the first embodiment will be described in detail with reference to the flowchart of FIG.

First, when image data is input, the input image is divided into a plurality of blocks, and a search is made for a portion having the highest correlation with a reference frame for each block (step S1). For example, the sum of the sum of squares of the difference values of each pixel, the sum of the absolute values of the difference values, and the like are obtained, and the portion having the minimum value within the search range is set as the position of the reference block. The distance to the reference block is obtained from the search result, the total value of the distance over one screen is calculated, and the value is compared with the threshold value A (step S2). If it is larger than the threshold value A, the compression process is performed as it is. Otherwise, the number of consecutive frames (skip count) for which the compression process is not performed is compared with the threshold value B (step S7). If it is larger than the threshold value B, the frame is subjected to compression processing. If not, the frame is not compressed and updated by adding 1 to the skip count (step S8). For the frame to be subjected to the compression processing, the skip count is first updated to 0 (step S3), and the frequency conversion is performed (step S3).
4) Perform quantization (step S5), and perform variable-length encoding on the result (step S6). This is repeated until all frames are completed (step S9).

Next, a specific example will be described. Assume that data of 9 frames per second is input as shown in FIG. Frame numbers 1 to 6 and 11 to 16 are images with little movement, and 7 to 10 are images with much movement. Scenes with little motion in advance are 3 frames per second,
Assuming that a scene with a lot of motion is compressed at 9 frames per second, the number of frames actually compressed is 1,
4, 7, 8, 9, 10, 13, and 16.

Referring now to FIG. 4 and FIG. 5, a method of determining a scene with a small motion and a scene with a large motion will be described. FIG. 4 is a diagram illustrating a scene with little motion. When the amount of movement of the object between the reference frame and the current frame is examined in block units, the figure shows the amount of movement. Assuming that the threshold value for the movement amount determination is 100, the total movement amount for the entire frame in FIG. 4 is 46, which is smaller than the threshold value, and is determined as a frame having a small movement amount. FIG. 5 is a diagram illustrating a scene with a large amount of movement. As shown in FIG. 4, the sum of the movement amounts for the entire frame is 168, which is the threshold value of 1
Since it is larger than 00, this frame is determined to be a frame with a large moving amount.

Next, a second embodiment of the present invention will be described. A case of a compression method in which the number of frames per unit time is defined, such as MPEG1, will be described with reference to FIG. FIG. 6 is a diagram showing a frame configuration of MPEG1. Frame types include I, P, and B. An I frame is compressed without using a reference frame, and a P frame is compressed with reference to either the previous I or P frame. The B frame is compressed with reference to the preceding or succeeding I or P frame, and the B frame itself is not used as a reference frame. In MPEG1, since the number of frames per unit time is specified, there is no frame that is not subjected to compression processing. Therefore, B-frame data that is not used as a reference frame should be treated as the same image as the reference frame. Since the data amount after compression becomes very small, the same effect as when no compression processing is performed can be obtained.

Referring to FIG. 7, in the second embodiment, an image input means 21, a motion search means 22, and a motion determination means 23
Frequency conversion means 24, quantization means 25, inverse quantization means 26, inverse frequency conversion means 27, motion compensation means 28, variable length coding means 29, data clear means 3
0 and output means 31.

Each of these means operates as follows. An image is input in units of one frame from the image input unit 21, and the motion search unit 22 divides the current frame into a plurality of blocks in order to determine the correlation between the previous frame stored as a reference frame and the current frame. Find out which part of the reference frame the block is highly correlated with. The distance to the block with the highest correlation is considered as the movement distance of the block from the reference frame. The motion determining means 23 calculates the sum of the movement amounts of the entire screen based on the movement distance of each block, and from this value, it is possible to know how much the current frame has changed from the reference frame.

If the current frame is an image having a lot of motion, difference data from a highly correlated block obtained by the motion search means 22 is input to the frequency conversion means 24. The difference data is converted into frequency components by the frequency conversion unit 24, and quantization is performed by the quantization unit 25. The data is converted into a compression code by the variable length coding means 29 and output by the output means 31. In order to create a reference frame for the next frame compression, the quantization means 2
The result of No. 5 is passed to the inverse quantization means 26 to perform inverse quantization. The inverse frequency conversion means 27 converts the frequency components into pixel components, and the motion compensation means 28 creates reference frame data.

If the current frame is an image with little motion,
If the number of frames is less than a predetermined number of frames, for example, 10 consecutive frames, the data clear unit 30 sets the difference data value from the previous frame to 0, the variable length coding unit 29 converts the data into a compression code, and the output unit 31 outputs the data. . In the eleventh frame, all the processes after the frequency conversion means 24 are performed.
If less than 10 consecutive frames,
If an image with a lot of motion is detected, the processing after the frequency conversion means 24 is performed without waiting for the eleventh frame.

The overall operation of the second embodiment will be described in detail with reference to the flowchart of FIG.

First, when image data is input, the input image is divided into a plurality of blocks, and a search is made for a portion having the highest correlation with a reference frame for each block (step S11). For example, the sum of the sum of squares of the difference values of each pixel, the sum of the absolute values of the difference values, and the like are obtained, and the portion having the minimum value within the search range is set as the position of the reference block. The distance to the reference block is obtained from the search result, the total value of the distance over the entire screen is calculated, and the value is compared with the threshold value A (step S12). If the threshold value is larger than the threshold value A, the compression process is performed as it is, otherwise, the threshold value B is compared with the number of consecutive frames (skip count) for which the compression process is not performed (step S16). If it is larger than the threshold value B, the frame is subjected to compression processing. Otherwise, the skip count is updated by adding 1 (step S17), and the difference data after the motion search is all treated as 0, that is, treated as the same image as the reference frame (step S1).
8). Then, variable-length encoding is performed to encode a frame having data of 0 (S19). For a frame to be subjected to compression processing, the skip count is first updated to 0 (step S
13) Perform frequency conversion (step S14), perform quantization (step S15), and perform variable-length encoding on the result (step S19). This is repeated until all frames are completed (step S20).

FIG. 9 shows the codes of the B frame when the difference data is 0. Starting with a PSC indicating the beginning of the frame,
The PCT indicates that the frame is a B frame. The compressed data is described in units of 16 × 16 pixel blocks (macro blocks). MBAI indicates an increment from the previous macroblock, and is 1 at the beginning. In MBTYPE, the format of a macroblock is described, and a MBP of 0 indicates that there is no data to be encoded in that macroblock. Also, MBESC indicates that there is no encoded data in 33 macroblocks. Since this is described twice, it can be seen that there is no encoded data in 66 macro blocks. The next MBAI is 13
This means that there is no encoded data for 12 more,
Since the MBP of the macroblock is 0, 13
It can be seen that there is no coded data for each piece. The image shown in this example is an image generated from 80 macro blocks, and the number of macro blocks not to be encoded is 1 + 66 + 1.
3 = 80, indicating that all macroblocks have not been coded. The data amount at that time is only 157 bits.

Next, a third embodiment of the present invention will be described in detail with reference to the drawings. Referring to FIG. 10, the third embodiment includes an image input unit 41, a difference detection unit 42, a motion determination unit 43, a motion search unit 44, a frequency conversion unit 45, a quantization unit 46, an inverse quantum It comprises an encoding means 47, an inverse frequency conversion means 48, a motion compensation means 49, a variable length encoding means 50, and an output means 51.

Each of these means operates as follows. An image is input from the image input unit 41 in units of one frame, and the difference between the current frame and the reference frame is obtained by the difference detection unit 42. For example, the amount of change can be obtained by obtaining the absolute value of the difference between the luminance components. The motion determining means 43 calculates the total sum of the magnitudes of the difference values over the entire screen based on the difference values of the pixels, and from this value, it is possible to know how much the current frame has changed from the reference frame.

If the current frame is an image having a lot of motion, the current frame is divided into a plurality of blocks in order to obtain the correlation between the previous frame stored as a reference frame and the current frame by the motion search means 44. Find out which part of the reference frame the block is highly correlated with. When the difference data from the highly correlated block is input to the frequency conversion unit 45, it is converted into a frequency component, and quantization is performed by the quantization unit 46. The data is converted into a compression code by the variable length coding means 50 and output by the output means 51. Further, in order to create a reference frame for the next frame compression, the result of the quantization means 46 is passed to the inverse quantization means 47 to perform inverse quantization, and the inverse frequency conversion means 48 converts the frequency component into a pixel component, The compensator 49 creates reference frame data.

If the current frame is an image with little motion,
If the number of frames is less than a predetermined number of frames, for example, ten consecutive frames, only the processing up to the motion determining means 43 is performed, and all the processing after the motion searching means 44 is performed on the eleventh frame. If an image with a lot of motion is detected by the motion determining means 43 within less than 10 consecutive frames, 11
The processing after the motion search means 44 is performed without waiting for the frame.

Next, the overall operation of the third embodiment will be described in detail with reference to the flowchart of FIG.

First, when image data is input, a difference between pixels in the input image at the same position as the reference frame is obtained (step S21). The amount of change in the entire screen is calculated from the difference value, and is compared with the threshold value D (step S22). If it is larger than the threshold value D, the compression process is performed as it is, and if not, the skip count is compared with the threshold value B (step S28). Threshold B
If it is larger, the frame is subjected to compression processing. Otherwise, without compressing the frame,
The skip count is updated by adding 1 (step S2)
9). The frame to be subjected to the compression process first updates the skip count to 0 (step S23). The input image is divided into a plurality of blocks, and for each block, a portion having the highest correlation with a reference frame is searched (step S).
24). The frequency conversion of the difference data obtained by the motion search is performed (step S25), and the quantization is performed (step S2).
6), the result is subjected to variable length coding (step S2)
7). This is repeated until all frames are completed (step S30).

Next, a specific example will be described. With reference to FIG. 12 and FIG. 13, a method of determining a scene with a small motion and a scene with a large motion will be described. FIG. 12 is a diagram illustrating a scene with little motion. When the difference between the reference frame and the current frame is examined on a pixel-by-pixel basis, the amount of change is as shown in the figure. The amount of change is determined based on how many pixels the difference value is larger than a threshold value C, for example, 10 pixels.
If the change amount is a threshold value D, for example, 15 pixels or more, it is determined that the scene has a lot of motion. In FIG. 12, 6 pixels have a difference value larger than 5 pixels, which is smaller than 15 pixels. It is determined that the frame has a small moving amount. FIG. 13 is a diagram illustrating a scene with a large amount of movement. As shown in FIG. 12, the number of pixels having a difference value larger than 5 is obtained as 20 from the diagram showing the amount of change, and since the difference value is larger than the threshold value of 15, this frame is determined to be a frame with a large moving amount. You. By providing the threshold value C in this manner, it is possible to determine the amount of change by removing a minute noise component generated on the screen.

[0036]

A first effect of the present invention is that the amount of compressed data can be reduced. The reason is that the number of frames to be actually compressed can be reduced by thinning out frames when there is almost no movement on the screen. The second effect is that smooth movement can be reproduced. The reason is that if the amount of movement of the object in the screen is large, the number of frames to be compressed per unit time is increased. The third effect is that a smooth motion can be reproduced without deteriorating the image quality. The reason is that by storing the compressed image in the storage medium, the data amount reduced when there is no motion can be transferred to compression when the motion is large.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a flowchart of the operation.

FIG. 3 is a diagram illustrating a specific example of the frame processing.

FIG. 4 is a diagram illustrating a scene with little motion.

FIG. 5 is a diagram illustrating a scene with a large amount of movement.

FIG. 6 is a diagram showing a frame configuration of MPEG1.

FIG. 7 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 8 is a flowchart of the operation.

FIG. 9 is a code diagram of a B frame when difference data is 0.

FIG. 10 is a block diagram showing a configuration of a third embodiment of the present invention.

FIG. 11 is a flowchart of the operation.

FIG. 12 is a diagram illustrating a scene with little motion.

FIG. 13 is a diagram illustrating a scene with a large amount of movement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Image input means 12 Motion search means 13 Motion determination means 14 Frequency conversion means 15 Quantization means 16 Inverse quantization means 17 Inverse frequency conversion means 18 Motion compensation means 19 Variable length coding means 20 Output means 21 Image input means 22 Motion search Means 23 Motion determination means 24 Frequency conversion means 25 Quantization means 26 Inverse quantization means 27 Inverse frequency conversion means 28 Motion compensation means 29 Variable length coding means 30 Data clear means 31 Output means 41 Image input means 42 Difference detection means 43 Motion Determination means 44 motion search means 45 frequency conversion means 46 quantization means 47 inverse quantization means 48 inverse frequency conversion means 49 motion compensation means 50 variable length coding means 51 output means

Continued on the front page F-term (reference) 5C053 FA01 GB23 GB26 GB32 GB37 HA33 5C059 KK01 MA00 MA05 MA23 MC11 MC38 ME01 ME17 NN01 NN27 NN28 PP05 PP06 PP07 SS11 TA07 TB04 TC12 TC13 TD12 UA02

Claims (5)

[Claims] 1. A method for receiving moving image data in frame units,
Motion search means for detecting how much the image has changed from the previous frame; motion determination means for determining whether or not the current frame is a moving image from the total of the changed amount of the entire screen; and a result of the determination Compression means for compressing only one frame of a predetermined number of frames when it is determined that the image has little motion, and compressing several consecutive frames when it is determined that there is much motion. A moving image compression apparatus, comprising: 2. Receiving moving image data in frame units,
A motion search unit which divides the current frame into a plurality of blocks, determines which part of the reference frame has a high correlation with each block, and determines a distance to the block having the highest correlation as a moving distance of the block from the reference frame; A motion determining unit that determines whether or not the current frame is a moving image by calculating the sum of the moving amounts of the entire screen based on the moving distance of each block, and a highly correlated block obtained by the motion searching unit. Frequency conversion means for converting the difference data into frequency components, and quantization means for quantizing the data after the conversion,
A variable-length encoding unit that performs variable-length encoding of the quantized data, and when the current frame is an image with little motion as determined by the motion determining unit, processing up to a predetermined number of frames is performed up to the motion determining unit. Is performed, and after that, the processing after the frequency conversion means is performed.If an image with a lot of motion is detected by the motion determination means within less than the predetermined number of frames continuously, the predetermined value is set. A moving image compression apparatus that performs processing after frequency conversion means without waiting for the number of frames. 3. Receiving moving image data in frame units,
A motion search unit which divides the current frame into a plurality of blocks, determines which part of the reference frame has a high correlation with each block, and determines a distance to the block having the highest correlation as a moving distance of the block from the reference frame; A motion determining unit that determines whether or not the current frame is a moving image by calculating the sum of the moving amounts of the entire screen based on the moving distance of each block, and a highly correlated block obtained by the motion searching unit. Frequency conversion means for converting the difference data into frequency components, and quantization means for quantizing the data after the conversion,
A variable-length encoding unit that performs variable-length encoding on the quantized data;
A data clear unit for setting the difference data value to 0, and when the current frame is an image with little motion as determined by the motion determining unit, the data clear unit determines the difference between the current frame and the previous frame up to a predetermined number of frames. The differential data value is set to 0, the variable-length coding means compresses the code, and after exceeding the value, the processing after the frequency conversion means is performed. A moving image compression apparatus that performs processing after frequency conversion means without waiting for a predetermined number of frames when an image with a lot of motion is detected. 4. A difference detecting means for calculating a difference between an input current frame and a reference frame, and a sum of magnitudes of the difference values over the entire screen based on a difference value of each pixel to determine a motion of the current frame. A motion judging means for judging whether or not the image is a certain image, and a motion for dividing the current frame into a plurality of blocks, determining which part of the reference frame has a high correlation with each block, and extracting difference data from the highly correlated block Search means, frequency conversion means for converting difference data between a highly correlated block into frequency components, quantization means for quantizing the converted data, and variable length code for performing variable length coding on the quantized data If the current frame is an image with little motion as determined by the motion determining means, only processing up to the predetermined number of frames is performed up to the motion determining means, After that, the processing after the motion search means is performed, and if an image with a lot of motion is detected by the motion determination means within less than the predetermined number of frames continuously, up to the predetermined number of frames. A moving picture compression apparatus characterized by performing processing after a motion search means without waiting. 5. An inverse quantization means for inversely quantizing the result of the quantization means, an inverse frequency conversion means for converting the result from a frequency component to a pixel component, and a reference for the motion search means from the converted data. 5. The moving picture compression apparatus according to claim 2, further comprising a motion compensation unit for creating a frame.