KR100322705B1 - System and method for compressing and decompressing image - Google Patents

Abstract

PURPOSE: A system and a method for compressing and decompressing an image are provided to divide functions of compression and decompression procedures and compress/decompress an image using a plurality of signal processing dedicated processors. CONSTITUTION: A system for compressing and decompressing an image includes the first to fifth buffers(40,48,50,60,58), the first and second signal processors(42,52) and a video controller(62). The first buffer receives and buffers the first data to be compressed and the second data to be decompressed. The first signal processor receives and compresses the first data to output the first compressed data, quantizes video data to output the video data as the third data, and decompresses the buffered second data to output the second data as the first decompressed data. The second buffer receives and buffers the third data or the second decompressed data under the control of the first signal processor. The third buffer buffers the first compressed data under the control of the first signal processor. The fourth buffer receives and buffers information concerned and compressed remainder data. The second signal processor processes the third data to obtain a remainder, encodes the remainder in response to the information concerned, outputs the encoded remainder as the second compressed data, decodes the compressed remainder data as the second decompressed data, and adds up the second decompressed data and the first decompressed data. The fifth buffer receives and buffers the second compressed data or the added decompressed data under the control of the second signal processor. The video controller controls the first buffer, the fourth buffer, the first and second processors.

Description

Image compression and decompression device and its compression and decompression method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image compression and decompression, and more particularly, to an image compression and decompression device and a method of compressing and decompressing a high speed process for compressing and decompressing an image requiring high speed transmission.

Various data compression algorithms have been studied to increase data storage efficiency and reduce transmission time. These algorithms can be classified as lossless (for areas of interest) or lossy (for areas of interest) compression algorithms. Here, a lossless algorithm is an algorithm capable of compressing and restoring digital information without loss, and a lossy algorithm is an algorithm that compresses and recovers information at a high compression ratio, but a loss occurs. Generally, lossy or lossless algorithms can be applied to all images. In particular, a lossless algorithm is an algorithm performed for a region of interest, and a lossy algorithm is an algorithm performed for a region of interest.

Recently, image data compression and decompression algorithms that can compress and decompress large amounts of data in a short time are required. This requires a high compression rate. This is because a high compression rate not only reduces data storage space but also shortens data transmission time through a communication network.

For example, for a smooth operation of a telemedicine system, a doctor must receive medical images of a remotely located patient and provide medical care in a short time. For this purpose, the image should be transmitted within a short time that can be transmitted from a remote site. However, since medical images generally have a large amount of data, the transmitting side of the medical image compresses and transmits the image, and the receiving side restores the original image. do. In other words, the compression rate is increased to transfer data at high speed.

However, there is a need for improvement since the time required for compression and decompression also takes a lot. In the case of a standard standard (JPEG: Joint Picture Expert Group) that compresses still images, gray levels can be processed up to 256 levels (8 bits). Since it must be able to process up to 4,096 levels (12 bits), there is a problem that it is difficult to implement using a conventional compression element or circuit.

Furthermore, if a difference occurs in the image after the restoration and the original image before compression, such as a medical image, the lossy compression method may not be used only in a situation where serious problems may occur. However, a lossless compression algorithm has a long data compression time and a problem in that compression efficiency is lowered.

In addition, in a situation where fast data transfer is required, image compression and decompression by conventional software takes a long time.

An object of the present invention is to divide the function of the compression and decompression process in order to solve the above problems, and to compress and reconstruct the image using two dedicated signal processing processor to enable parallel processing through the pipeline It is to provide a compression and decompression device.

Another object of the present invention is to divide the function of the compression and restoration process to solve the above-mentioned conventional problems, parallel processing through the pipeline, and four signal processing dedicated to perform compression and restoration at the same time The present invention provides an image compression and decompression device that compresses and decompresses an image using a processor.

Still another object of the present invention is to provide a method of compressing and restoring an image performed by the apparatus for compressing and restoring an image according to the present invention.

In order to achieve the above object, in response to the interest information on the region of interest data of the image data according to the present invention, the first data, which is the image data divided for being compressed, and the second data and the compression residual data, which are the image data to be restored, are obtained. The apparatus for inputting, compressing and decompressing, and outputting the first and second compressed data finally compressed and the processed data as the finally restored first and second restored data, respectively, includes the first data and the first data. A first buffer for inputting and buffering 2 data, and inputting the first data, and outputting the compressed data as the first compressed data, quantizing the image data, and outputting the third data, and buffering the second data. First signal processing means for restoring and outputting the first data as the first restored data, and controlled by the first signal processing means to restore the third data or the second restored data. A second buffer for inputting and buffering data, a third buffer controlled by the first signal processing means to buffer the first compressed data, and a fourth buffer for inputting and buffering the interest information and the compressed residual data; Process the third data buffered in the second buffer to obtain a residual, encode the residual in response to the interest information output from the fourth buffer, and output the encoded residual as the second compressed data. Second signal processing means for decoding the compressed residual data into the second restored data in response to the interest information, and adding and outputting the second restored data and the first restored data; and the second signal processing. A fifth buffer controlled by means for inputting and buffering the second compressed data or the added reconstructed data; and the first buffer, the fourth buffer, the first and second digital. And image control means for controlling the de-processing means.

In order to achieve the above another object, the image data to be compressed and the image data to be restored according to the present invention are input, compressed and decompressed, and finally compressed first and second compressed data and finally restored first and first The apparatus for outputting the processed data as the two-restored data includes: a first buffer for inputting and buffering the image data divided for compression; and an output of the first buffer; First signal processing means for outputting and quantizing the video data as third data; a second buffer controlled by the first signal processing means to input and buffer the third data; and the first signal processing means. A third buffer controlled to buffer the first compressed data, a fourth buffer configured to input and buffer the interest information on the ROI of the image data, and an input; Second signal processing means for processing the third data to obtain a residual, encoding the residual in response to the output of the fourth buffer, and outputting the encoded residual as the second compressed data; A fifth buffer for buffering the second compressed data, a sixth buffer for inputting and buffering the data to be restored, and restoring the output of the sixth buffer to output as the first restored data. A third signal processing means, a seventh buffer controlled by the third signal processing means to buffer the output of the third signal processing means as the first restoration data, and input and buffer the interest information and the compressed residual data. Inputting the eighth buffer and the interest information to decode the corresponding compression residual data as the second restored data, and adding the outputs of the second restored data and the seventh buffer; A fourth signal processing means for outputting, a ninth buffer for buffering the added result output from the fourth signal processing means, and the first, fourth, sixth, eighth buffers, and the first, second, third and fourth buffers; And image control means for controlling the signal processing means.

In accordance with another aspect of the present invention, there is provided an image compression and decompression method of an apparatus for compressing and restoring an image, the method including: a first judging step of determining whether to compress or decompress the image; An image compression step of compressing the image divided into blocks, a second judging step of determining whether the compression of the image of the block is lossless compression, a residual compression step of compressing the residuals if the lossless compression is performed, and If it is determined that the image of the block is lossy compression or the corresponding block compressed after the residual compression step is finally the block to be compressed, the compression of the image is terminated, and if it is not the final block, the image compression step proceeds. And a third judgment step of restoring the image, if the image is to be restored, restoring the compressed image of the corresponding block. And a fourth judging step of determining whether the restoration is a lossless restoration, a residual restoration step of restoring the residual if the restoration is lossless restoration, and the corresponding block after the restoration is a lossy restoration or the residual restoration stage. If it is determined that the last block to be restored is satisfied, it is characterized in that it comprises a fifth judging step of ending the restoration of the image and proceeding to the image restoration step if it is not the last block.

Hereinafter, an apparatus and method for compressing and restoring an image according to the present invention will be described in detail as follows with reference to the accompanying drawings, while comparing with a conventional method for compressing and restoring an image.

1 is a flowchart for explaining a conventional image compression method, comprising: quantizing an image (steps 10 to 12) and determining whether an image is a region of interest or an indifferent region (step 14). And compressing the data (sixteenth to twenty-second steps).

2 is a diagram for describing a conventional image reconstruction method, and includes a first decoder 30, an inverse quantization unit (Q− ¹ ) 32, an inverse discrete cosine transcript (IDCT), or a DCT- ^1. ), The second decoder 34 and the adder 36.

The conventional compression apparatus inputs the image data to be compressed to perform discrete cosine transform (step 10), and quantizes the discrete cosine transformed data after step 10 (step 12). After the twelfth step, it is determined whether the portion of the image to be originally processed is the region of interest (step 14), and if the region of interest is a residual (step 18). In order to obtain the residual, inverse quantization of the quantized data and then the value obtained by inverse discrete cosine transform is subtracted from the original image data. After the eighteenth step, the residuals are compressed (step 20). If the portion of the original image to be processed is not the region of interest, the quantized image data is encoded and compressed (step 16). After the 16th and 20th steps, the compressed data may be transmitted (step 22).

In order to restore the compressed image data using the conventional reconstruction apparatus, the first decoder 30 shown in FIG. 2 inputs the compressed image data through the input terminal IN and outputs the compressed image data to the inverse quantization unit 32. The inverse quantized data in the inverse quantization unit 32 is input to the inverse discrete cosine transform unit 33, inverse discrete conversion, and then output to the adder 36. Meanwhile, the second decoder 34 decodes the compressed residual data through the input terminal IN2, and inputs information (interest information) of the image data corresponding to the decoded residual data through the input terminal IN3. The adder 36 adds the outputs of the second decoder 34 and the DCT- ¹ 33 to output to the monitor (not shown) as image data reconstructed through the output terminal OUT.

3 is a block diagram of a preferred embodiment of an image compression and decompression device according to the present invention, and includes a first input first output (FIFO) 40, a first signal processor 42, and a first ROM. (ROM) 44, first RAM 46, second FIFO 48, third FIFO 50, second signal processor 52, second ROM 54, second RAM 56 Control the fifth FIFO 58, the fourth FIFO 60, and the fourth FIFO 60 and the first FIFO 40, reset the first and second signal processors 42 and 52, and interrupt signals thereto. It consists of an image control unit 62 to provide. Here, the FIFO is a device having a buffering function of outputting first input data first.

4 is a flowchart illustrating a method of compressing and restoring an image according to the present invention, comprising: initializing an image (step 70), determining whether to compress an image (step 72), and a block. And dividing and compressing the video data (steps 74 to 80), and restoring the compressed image divided into blocks (steps 82 to 88).

When the apparatus according to the present invention is used double with a personal computer (PC), the PC divides a region to be processed into images in block units (N ₁ × N ₂ ) and transmits the same to the apparatus according to the present invention. Read compressed video data from the device. That is, the PC sets a lossless compression area for the area of the entire image to be processed, calculates the total number of blocks in that area, and sends it to the apparatus of the present invention.

An apparatus and method for compressing and reconstructing image data according to the present invention will be described as follows.

The image controller 44 shown in FIG. 3 outputs the address control signals C2 and C4 to the first and second signal processors 42 and 52, respectively, and the first and second signal processors 42 and 52 respectively address. In response to the control signal, the first RAM 46 and the second RAM 56 read the boot programs stored in the first ROM 44 and the second ROM 54, respectively. The first and second signal processors 42 and 52 are controlled and initialized by the image controller 62 using a booting program stored in the first and second RAMs 46 (step 70). The image controller 62 determines whether the image data input through the input terminal IN2 is compressed data or data to be compressed (step 72).

After the 72th step, if the data divided in block units is data to be compressed, the first FIFO 40 controlled by the control line C1 output from the controller 62 receives the image data from the PC through the input terminal IN1. Enter it. The first signal processing unit 42 is controlled by the control line C2 output from the image control unit 62 and inputs and compresses the image data divided in units of blocks from the first FIFO 40.

5 is a diagram illustrating in detail the compression process performed in FIG. 3 and the functions of the signal processing units. The segmentation unit 94 for dividing image data into blocks and the image control unit 62 shown in FIG. A first digital signal processing unit composed of a PC 90 comprising a control unit 96, a DCT unit 98, a quantization unit 100, a scan unit 102, and a first encoder 104. (DSP: Digital Signal Processor) 92, a second digital signal processor 91 composed of an inverse quantizer 106, an inverse DCT unit 108, an adder 110, and a second encoder 112. do.

The first signal processor 42 shown in FIG. 3 processes a process (step 74) of compressing image data divided into blocks performed by the first digital signal processor 92 shown in FIG. In other words, the data input from the divider 94 through the first FIFO 40 theory is subjected to discrete cosine transforming by the DCT unit 98 and quantized by the quantization unit 100 (step 73). The second signal is output to the second signal processor 52 through the second FIFO 48 shown in FIG. The scan unit 102 scans the quantized data by zigzag and outputs the zigzag to the first encoder 104. The first encoder 104 encodes the quantized data and then compresses the quantized data through the output terminal OUT1. Output to the third FIFO 50 shown.

As the encoding method, Lempel-Ziv (LZ) coding method or Huffman coding methods may be used. For this operation, the first signal processor 42 reads programs from the first RAM 46.

Meanwhile, the second signal processor 52 shown in FIG. 3 inputs the image data of the corresponding quantized block stored in the second FIFO 48 and inputs it to the inverse quantizer 106 as shown in FIG. Inverse quantization, input to the inverse DCT unit 108 to perform an inverse discrete cosine transform and output to the adder (110). The adder 110 subtracts the data output from the inverse DCT unit 108 from the image data divided into the blocks output from the divider 94 through the first FIFO 40, and subtracts the data output from the inverse DCT unit 108. (Or the residual), it outputs to the 2nd encoder 112. As shown in FIG.

The video controller 62 determines whether to compress the video data of the block losslessly or losslessly (step 76). If the video controller 62 is lossless compression, the input terminal IN3 of the fourth FIFO 60 shown in FIG. Through the control to input the information on the region of interest from the personal computer. The second encoder 112 of the second signal processor 52 compresses the residual data in response to the information on the ROI (step 78). That is, if the corresponding image block is the region of interest, the second encoder 112 compresses the residual data and outputs the residual data to the fifth FIFO 58 through the output terminal OUT2. However, if the image block is the region of interest, the residual data is not compressed.

After operation 78, the image controller 62 determines whether the compressed block is the final block to be compressed (operation 80). If the compressed block is the last block 140-N shown in Figs. 7A and 7B, the compression of the image data is terminated, and steps 74 to 78 are performed until the last block if the compressed block is not the last block. Do it repeatedly.

When reconstructing the image after step 70, the image compression and decompression device and the method (steps 82 to 88) of the present invention will be described as follows.

FIG. 6 is a diagram for explaining in detail the restoration process performed in FIG. 3 and the function of each signal processor. The personal computer 120 including the control unit 138, the first decoding 126, and the reverse scan are shown in FIG. A second digital signal composed of a first digital signal processor 122 composed of a unit 128, an inverse quantization unit 130, and an inverse DCT unit 132, a second decoder 134, and an adder 136. It consists of a processing unit 124.

The first FIFO 40 shown in FIG. 3 inputs and buffers the compressed image data through the input terminal IN1. Meanwhile, the fourth FIFO 60 inputs and buffers information on the ROI through the input terminal IN3.

After operation 70, the first signal processor 42 restores the compressed image data, which is divided into blocks and input as follows (operation 82). That is, the first decoding unit 126 shown in FIG. 6 of the first signal processing unit 42 inputs and decodes the data buffered in the first FIFO 40 through the data line D1 and decodes the data. 128 inputs the reverse zigzag scan and outputs it to the inverse quantization unit 130. The inverse quantizer 130 quantizes the input data. The inverse DCT unit 132 decodes the inverse quantized data by the opposite method that was coded at the time of compression and outputs the decoded image data to the second FIFO 48 shown in FIG. 3 as first restored data.

FIG. 7A is a view for explaining the structure of the blocked image data input to the first FIFO 40 through the input terminal INl, and the image data is blocked from block 1 140-1 to block N 140-N. do.

7B is a diagram for explaining that the compressed video data output from the third FIFO 50 is blocked and output through the output terminal OUT2.

7C is a diagram showing that the compressed residual data output from the fifth FIFO 58 through the output terminal OUT1 is blocked and output.

In response to lossless decoding or lossy decoding (step 84), the compressed residual data of the corresponding block is buffered in the fourth FIFO 60. In the case of lossless restoration, the second decoding unit 134 of the second digital signal processing unit 124 receives the residual data and the video signal to be decoded buffered in the fourth FIFO 60 shown in FIG. 3 through the input terminal IN2. Information about the area is input, and the compressed residual data is restored (step 86) and output to the adder 136. The adder 136 adds the two input data and outputs the second restored data, which is the final reconstructed image data, to the fifth FIFO 58 shown in FIG. 3 through the output terminal OUT shown in FIG.

After the 86th step, the image control unit 62 determines whether the block is the last block to be restored (step 88). Each part of the apparatus according to the present invention is controlled to repeatedly perform the operations of steps 82 to 88 until the last block 140-N shown in FIG.

The above-described image compression and decompression device according to the present invention performs pipeline processing using two digital signal processing means in order to process compression and decompression of an image at high speed, and has temporal parallelism. However, if the apparatus shown in FIG. 3 requires compression and restoration, only one of restoration or compression operations can be selected and processed, and the image compression and restoration apparatus according to the present invention for solving this problem is as follows. Explain.

8 is a block diagram illustrating another embodiment of an image compression and decompression device according to the present invention, and includes a first FIFO 150, a first DSP 152, a first ROM 154, a second RAM 156, and a second FIFO. A compression unit 191 including a third FIFO 160, a second DSP 162, a second ROM 164, a second RAM 166, a fifth FIFO 168, and a fourth FIFO 170; 6FIFO 172, 3DSP 174, 3ROM 176, 3RAM 178, 7FIFO 180, 4DSP 182, 4RAM 184, 4ROM 186, 8FIFO ( 188, a reconstruction unit 182 including the ninth FIFO 187 and the image control unit 190.

The operation of FIG. 8 will be briefly described as follows.

The first FIFO 150 shown in FIG. 8 inputs and buffers the divided image data through the input terminal IN1 for compression, and the first DSP 152 inputs the output of the first FIFO 150. The compression process is performed by performing the procedure shown in FIG. 3, and the compressed data as the first compressed data is output to the third FIFO 160, and the quantized image data is output to the second FIFO 158 as the third data. Here, the second FIFO 158 is controlled by the first DSP 152, inputs and buffers the third data, and the third FIFO 160 is also controlled by the first DSP 152 to buffer the first compressed data. The second DSP 162 processes the third data input from the second FIFO 158 to obtain a residual, and inputs and buffers the interest information of the data region of interest of the image data through the input terminal IN3 to buffer the fourth data. In response to the output, the residuals are encoded and the encoded residuals are output to the fifth FIFO 168 as second compressed data. Here, the fifth FIFO 168 is controlled by the second DSF 162, and buffers the second compressed data, and the sixth FIFO 172 serves to input and buffer data to be restored through the input terminal IN2. 174 restores the output of the sixth FIFO 172 and outputs it to the seventh FIFO 180 as the first restoration data. Here, the seventh FIFO 180 is controlled by the third DSP 174 to buffer the output of the third DSP 174 which is the first restoration data. The fourth DSP 182 inputs the output of the eighth FIFO 188, which serves to buffer the information of interest and the compressed residual data through the input terminal IN3, and decodes the corresponding compressed residual data as the second restored data. The second restored data and the output of the seventh FIFO 180 are added to the ninth FIFO 187. Here, the ninth FIFO 187 serves to buffer the added result output from the fourth DSP 182. The image controller 190 controls the first, fourth, sixth and eighth FIFOs 150, 170, 172, and 188 and the first, second, third, and fourth DSPs 152, 162, 174, and 182.

As described above, the apparatus for compressing and restoring an image according to the present invention and the method for compressing and restoring performed by the apparatus perform parallel processing by using a plurality of digital dedicated processors, so that high-speed compression and It is possible to restore, compress and restore lossless images by setting the lossless compression area and lossless compression and restoring the remaining areas. High compression efficiency, installed on a personal computer, compresses and restores a single board. Function can be provided at the same time, and used in the same places as the telemedicine medical care system, which can compress and restore the medical image precisely while reducing the waiting time of the doctor and the patient, and also perform the compression and restoration operation at the same time. There is.

1 is a flowchart for explaining a conventional video compression method.

2 is a view for explaining a conventional image restoration method.

3 is a block diagram of a preferred embodiment of an image compression and decompression device according to the present invention.

4 is a flowchart for explaining an image compression and decompression method according to the present invention.

FIG. 5 is a diagram for describing in detail the compression process performed in FIG. 3 and the function of each signal processor.

FIG. 6 is a diagram for describing in detail the restoration process performed in FIG. 3 and the function of each signal processor.

7A to 7C are diagrams for explaining a process in which an apparatus according to the present invention processes image data in a pipeline.

8 is a block diagram illustrating another embodiment of an image compression and decompression device according to the present invention.

Claims (19)

In response to the interest information on the region of interest of the image data, the first data, which is the image data divided for being compressed, and the second data and the compressed residual data, which are the image data to be restored, are input, compressed, decompressed, and finally In the apparatus for outputting the first and second compressed data and the data processed as the first and second restored data finally restored, respectively, A first buffer configured to input and buffer the first data and the second data; The first data is input, after compression, output as the first compressed data, the image data is quantized and output as the third data, and the buffered second data is restored and output as the first restored data. First signal processing means; A second buffer controlled by the first signal processing means to input and buffer the third data or the second restored data; A third buffer controlled by the first signal processing means to buffer the first compressed data; A fourth buffer configured to input and buffer the interest information and the compressed residual data; Processing the third data buffered in the second buffer to obtain a residual, encoding the residual in response to the interest information output from the fourth buffer, outputting the encoded residual as the second compressed data, and Second signal processing means for decoding the compressed residual data into the second restored data in response to the interest information, and adding and outputting the second restored data and the first restored data; A fifth buffer controlled by the second signal processing means to input and buffer the second compressed data or the added restored data; And And image control means for controlling the first buffer, the fourth buffer, and the first and second digital processing means. The method of claim 1, wherein the first, second, third, fourth and fifth buffers are pre-input pre-output buffers. The image compression and decompression device of claim 1, wherein Image compression and decompression device, characterized in that the function of the image control means can be performed by a personal computer. The method of claim 1, wherein the first signal processing means A first ROM controlled by the first signal processing means to store programs executed by the first signal processing means; And And a first RAM controlled by the first signal processing means to read out the programs stored in the first ROM, and temporarily storing and outputting data processed by the first signal processing means. And restore device. The method of claim 1, wherein the second signal processing means A second ROM controlled by the second signal processing means to store programs executed by the second signal processing means; And And a second RAM controlled by the second signal processing means to read the programs stored in the second ROM, and temporarily storing and outputting data processed by the second signal processing means. And restore device. The image compression and decompression device of claim 1, wherein the image compression and decompression device comprises one board and can be mounted and used in a slot of a personal computer. The apparatus of claim 1, wherein the image data is medical image data transmitted from a remote location. The apparatus of claim 1, wherein the image data is a medical image transmitted from a remote location. Input image data to be compressed and image data to be restored, and perform compression and decompression processing, and output processed data as finally compressed first and second compressed data and finally restored first and second restored data, respectively. In the apparatus, A first buffer for inputting and buffering the divided image data to be compressed; First signal processing means for inputting the output of the first buffer, outputting it as the first compressed data after compression, and quantizing the image data and outputting it as third data; A second buffer controlled by the first signal processing means to input and buffer third data; A third buffer controlled by the first signal processing means to buffer the first compressed data; A fourth buffer configured to input and buffer the interest information on the ROI of the image data; Second signal processing means for processing the inputted third data to obtain a residual, encoding the residual in response to the output of the fourth buffer, and outputting the encoded residual as the second compressed data; A fifth buffer controlled by the second signal processing means to buffer the second compressed data; A sixth buffer for inputting and buffering the data to be restored; Third signal processing means for restoring the output of the sixth buffer and outputting the first restored data; A seventh buffer controlled by the third signal processing means to buffer the output of the third signal processing means which is the first restoration data; An eighth buffer configured to input and buffer the interest information and the compressed residual data; Fourth signal processing means for inputting the interest information to decode the corresponding compressed residual data as the second restored data, and adding and outputting the second restored data and the seventh buffer; A ninth buffer buffering the added result output from the fourth signal processing means; And And image control means for controlling the first, fourth, sixth, eighth buffers and the first, second, third and fourth signal processing means. 10. The apparatus of claim 9, wherein the first, second, third, fourth, fifth, sixth, seventh, eighth and ninth buffers are pre-input pre-output buffers. The method of claim 9, wherein the first signal processing means A first ROM controlled by the first signal processing means to store programs executed by the first signal processing means; And And a first RAM controlled by the first signal processing means to read out the programs stored in the first ROM, and temporarily storing and outputting data processed by the first signal processing means. And restore device. The method of claim 9, wherein the second signal processing means A second ROM controlled by the second signal processing means to store programs executed by the second signal processing means; And And a second RAM controlled by the second signal processing means to read the programs stored in the second ROM, and temporarily storing and outputting data processed by the second signal processing means. And restore device. The method of claim 9, wherein the third signal processing means A third ROM controlled by the third signal processing means to store programs executed by the third signal processing means; and And a third RAM, which is controlled by the third signal processing means, reads out the programs stored in the third ROM, and temporarily stores and outputs data processed by the third signal processing means. And restore device. The method of claim 9, wherein the fourth signal processing means A fourth ROM controlled by the fourth signal processing means to store programs executed by the fourth signal processing means; And And a fourth RAM controlled by the fourth signal processing means to read out the programs stored in the fourth ROM, and temporarily store and output data processed by the fourth signal processing means. And restore device. The image compression and decompression device of claim 9, wherein the image compression and decompression device is composed of one board and can be mounted and used in a slot of a personal computer. The image compression and decompression device of claim 9, wherein Image compression and decompression device, characterized in that the function of the image control means can be performed by a personal computer. The image compression and decompression device of claim 9, wherein the image data is medical image data transmitted from a remote location. In the image compression and decompression method of the device for compressing and restoring an image, A first determining step of determining whether to compress or restore the image; An image compression step of compressing the image divided into blocks if the image is to be compressed; A second judging step of determining whether the compression of the image of the corresponding block is lossless compression; A residual compression step of compressing the residual if the lossless compression; If the image of the corresponding block is lossy compression or the residual block compressed after the residual compression step is determined to be satisfied, the compression of the image is terminated. If not, the image compression step is performed. Proceeding to the third judging step; An image restoration step of restoring the compressed image of the corresponding block if the image is to be restored; A fourth judging step of determining whether the restoration is a lossless restoration; A residual restoration step of restoring the residual if the restoration is lossless restoration: and A fifth judging step of determining whether the restoration is a lossy restoration or whether the corresponding block is the block to be finally restored after the residual restoration step, and restoring the image if the restoration is satisfied; otherwise, proceeds to the image restoration step. Image compression and decompression method comprising the. 19. The method of claim 18, wherein the image is a medical image transmitted from a remote location.