JPH0774969A - Picture processing method and its device - Google Patents

Abstract

PURPOSE:To make it possible to compress/extend blocks even when the size of a picture is not integer times the size of a block. CONSTITUTION:A CPU 101 divides an input picture into blocks each of which has size to be processed by a compressing/extending processor 106 and stores the size of a picture which does not fill a prescribed size out of divided pictures in an identification table prepared in a RAM 102 or the like. A divided block of the prescribed size is stored in a block buffer 106 as it is and a divided block less than the prescribed size is converted into a block of the prescribed size and then stored in the buffer 106. In the case of extending data, compressed data are extended and stored in the block buffer 106, blocks not stored in the identification table are validated as they are, and in the case of blocks stored in the table, only unconverted picture data are validated in accordance with the sizes of converted blocks stored in the table to restore the compressed picture to the picture of the original size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method and apparatus for encoding / decoding an image, for example, when the block encoding is performed and the image size is not an integral multiple of the block size. However, the present invention also relates to an image processing method and apparatus capable of encoding / decoding.

[0002]

2. Description of the Related Art Conventionally, when coding a block,
There is a limit to the size of the image that can be encoded. For example,
ADCT of JPEG, which is one of the compression methods for color images
In the system, the image size needs to be a multiple of 8 both vertically and horizontally in order to perform processing for each block of 8 × 8 size. Therefore, an image with a size of 100 pixels × 100 pixels must be processed into 96 × 96 or 104 × 104.

For example, in a system that does not have a memory for an A4 size document, a method of having a buffer of several lines, storing an image in the buffer and then repeating compression is used to compress image data for one screen. To be Specifically, when reading an original document as shown in FIG. 3 with a scanner, a reading unit 402 as shown in FIG. 4A moves in the main scanning direction (x direction) to scan the original document, and then the sub document. Consider the case of moving in the scanning direction (y direction) as an example.

As shown in FIG. 3, in the first scan, 30
Bands 301 to 310 are repeatedly scanned, such as part 1 (hereinafter referred to as band), band 302 at the second time, and so on. In this case, 401 in FIG. 4A corresponds to the band 301 in FIG.
If the size of the band (the size in the x direction and the y direction) is a multiple of 8, the original is read as it is,
The data written in the buffer 403 shown in FIG.
Block compression of 8 pixels is possible.

[0005]

However, when the band size (size in the x direction and y direction) is not a multiple of 8, the written data can be compressed into blocks of 8 pixels × 8 pixels. It's gone. Alternatively, even if the size of the band (the size in the x direction and the y direction) is a multiple of 8, if the image is written in the buffer 403 after resolution conversion or the like here, it will not be a multiple of 8. There is a possibility that the written data cannot be compressed into a block of 8 pixels × 8 pixels.

[0006]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, M ×
Dividing means for dividing an image having a size of N into blocks of a size of m × n, and storage means for storing the size of an image of a size less than m × n divided by the dividing means,
First reconstructing means for reconstructing an image of a size less than m × n divided by the dividing means into a size of m × n, m × n blocks divided by the dividing means, and the first And an encoding unit for encoding the m × n blocks reconstructed by the reconstructing unit.

Further, for example, further, decoding means for decoding the encoded image into m × n blocks, identification means for identifying the blocks reconstructed by the first reconstructing means, and reconstructing means stored in the storage means are provided. Second reconstruction means for reconstructing the image decoded by the decoding means according to the size of the constituent blocks, and restoration for restoring the image reconstructed by the second reconstruction means to an image of size M × N And means.

[0008]

With the above construction, it is possible to perform encoding or decoding even when the image size is not an integral multiple of the block size.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a block configuration of an image processing apparatus according to an embodiment of the present invention. In FIG. 1, 101
Is a CPU for controlling the entire apparatus of this embodiment, 102
Is a random access memory (RAM), 103 is a read only memory (R) in which programs and data are stored.
OM). A scanner interface 104 is connected to an external scanner 151 and controls the interface with the scanner 151. Reference numeral 105 is a line buffer for temporarily storing the data read by the scanner 151. The line buffer 105 is
It corresponds to 403 shown in FIG.

Reference numeral 106 is a block buffer, 107 is a compression / expansion processor for encoding (compressing) or decoding (expansion) an image.
The compression method in 07 is a compression / decompression method in which processing is performed in block units. Conceptually, the block buffer 106 has a configuration shown in 110, and is a matrix of 8 pixels in the vertical direction and 8 pixels in the horizontal direction, and is divided into 64 cells numbered from 0 to 63 for convenience. To be The data is temporarily stored in the block buffer 106 before being input to the compression / expansion processor 107, and then processed. The compressed (encoded) data is stored in the compression memory 108.

The CPU 101, RAM 102, RO
The M103, scanner interface 104, line buffer 105, and block buffer 10 are connected to each other via a bus 109. Next, the data flow in the apparatus of this embodiment having the above configuration will be described. The CPU 101 has a scanner interface 104.
The data is read from the external scanner 151 via the, and the read data is written in the line buffer 105.

There are two reading methods by the scanner 151, as shown in FIGS. 2 (a) and 2 (b).
The first method shown by 201 in FIG. 2A is the sensor 20.
3 is a configuration in which a predetermined number of light receiving elements are arranged in the direction y, and the sensor 203 having a predetermined number of light receiving elements arranged in the direction y is moved in the x direction to scan the read document, and in the y direction. It is a method of repeating moving.

A second method 202 shown in FIG. 2B is a structure in which the light receiving elements of the sensor 204 are arranged in the x direction for the reading width, and the entire sensor performs scanning while moving in the y direction. Is. Other various scanning methods are possible, but in any case, the original sensor data is read while the entire sensor moves, and the read data is written in the line buffer 105.

The data written in the line buffer 105 is sent to the block buffer 106 by the CPU 101 as an 8 × 8 block. Compression / expansion processor 10
In No. 7, the compression process is performed when the data is arranged in the cell 110. The data is written to the compression memory 108. The CPU 101 must control the bus at this time. Conversely, when decompressing data, the compression / decompression processor 10
Reference numeral 7 extracts data from the compression memory 108, decompresses (decodes) the data, and writes the data in the block buffer 106. CP
The U 101 reads data from the block buffer 106 and writes the data in the RAM 102 and the line buffer 105.

The above is the general flow of data. Next, the detailed flow will be described. The following description is for the scanner 151
Will be described as an example in which scanning is performed by the first method shown in FIG. First, the first band 301 shown in FIG.
Consider the case of reading (corresponding to 401 in FIG. 4). The sensor 203 of the scanner 151 (sensor 4 in FIG.
02) starts scanning in the x direction. If the scanner 15
When 1 is read at a resolution equal to (or equal to) the reading resolution of its own scanner, it has 88 pixels in the vertical direction and 152 pixels in the horizontal direction, which is a multiple of 8 in both the vertical and horizontal directions. Therefore, the read data is divided into 8 × 8 blocks, and the compression / expansion processor 107 can perform block compression without any problem.

However, in the case where resolution conversion is performed, the number of pixels may not be a multiple of 8 as a result of resolution conversion. In such a case, it becomes difficult to perform block compression as it is. Become.
For example, when the resolution is halved and the reading is performed, the sensor 203 scans at a double speed in the x direction, and the cell (light receiving element) of the sensor 203 in the y direction as compared with the case of the same size. Is halved to read the data. Then, this is changed to the line buffer 105 (403 in FIG. 4B).
Equivalent to. ), The image having a resolution of 1/2 is input to the line buffer 105. That is, in the example of FIG. 4, even if the original image size is the size shown in FIG. 4A, when the resolution is converted to 1/2, the total area ratio is as shown in FIG. In 1
It becomes / 4 and is stored.

The resolution input in this way is 1/2
FIG. 5 shows an example of a block when the image of FIG. As shown by 601, the entire input image has “vertical 44 pixels, horizontal 76 pixels” which is half of “vertical 88 pixels, horizontal 152 pixels” at the same size. That is, as a result of resolution conversion, it is not a multiple of 8.

Even when such an input image is not a multiple of 8, when the input image from the line buffer 105 is stored in the block buffer 106, as shown in FIG.
As indicated by reference numeral 601, the input image is divided into 8 × 8 blocks from the upper left and stored in the block buffer 106. Then, when it advances to 0 block and 1 block and becomes 9 blocks shown by 602, since this block has a size of 4 pixels in the horizontal direction and 8 pixels in the vertical direction, the block is compressed even if it is sent to the compression / expansion processor 107 as it is. Can not be. Therefore, in this embodiment, 602
In block 9 shown in FIG. 6, as shown by 603, the pixels (3, 11, 19, 27, 35, 43, 51, 5 in the fourth column
9) is repeated from the fifth column to the eighth column, converted into a block of 8 × 8 size and stored in the block buffer 107. Then, this converted block data is sent to the compression / expansion processor 107 to perform block compression. Similar processing 6
In 01, it is also applied to 19 blocks, 29 blocks, 39 blocks, and 49 blocks.

Further, in 601 of FIG. 5, the 50 blocks indicated by 604 are 4 pixels in the vertical direction and 8 pixels in the horizontal direction as they are. As a result, block compression cannot be performed even if it is sent to the compression / expansion processor 107 as it is as described above. Therefore, in this embodiment, the 50 blocks indicated by 604 are converted into pixels (2
4, 25, 26, 27, 28, 29, 30, 31) 5
Repeat from the 8th line to the 8th line to convert to a block of size 8 × 8. The same processing is performed in 601, 50 blocks, 51 blocks, 52 blocks, 53 blocks, 5
It is applied to 4 blocks, 55 blocks, 56 blocks, 57 blocks and 58 blocks.

Further, in 601 of FIG. 5, 59 blocks indicated by 606 are vertical 4 in the actual block as it is.
Since the number of pixels is 4 pixels in the horizontal direction, the pixels are repeated in the same manner as the above processing to be converted into an 8 × 8 block as indicated by 607. In this way, by repeating the pixels at the boundary of the actual block, the compression / expansion processor 107 can perform compression. Then, the compression result is stored in the compression memory 108. The above processing also has an effect that it is possible to suppress the deterioration of the image quality when the image is expanded again.

As described above, image data of any size can be converted into an 8 × 8 block as a result, and the block compression can be performed. However,
When the compressed data including the block-converted compressed data is decompressed, the problem as shown in FIG. 6 occurs as it is. That is, assuming that the decompressed image is 501 shown in FIG. 6, as a result of the above processing, a portion shown by 502 in FIG. 6 is formed as an extra portion as an image.

In order to prevent this situation, it is necessary to store the size of this extra data somewhere as information when decompressing. Therefore, in this embodiment, for example, as shown in FIG. 7, a block information table is provided in the header of the compressed data and the original block information is secured in this table. More specifically, 702 shown in FIG. 7 is the compressed data of the image itself, and simply decompressing this data includes an extra portion as shown in FIG. 70
Reference numeral 1 is a header relating to compression, which includes various data such as the size of the entire image. A block information table 703 is provided as a part thereof.

The block information table 703 stores information about blocks that do not actually have a size of 8 × 8 (pixels are added). That is, actually 8 ×
A conversion block number not having a size of 8, a vertical pixel number and a horizontal pixel number in the conversion block number are stored. For example, an example of the block information table when the block information shown in FIG. 5 is compressed is shown in 704 of FIG. 7
In the block information table showing the detailed example in 04,
When the 9 blocks are expanded, the vertical 8 pixels and the horizontal 4 pixels are effective, and the 50 blocks are the vertical 4 pixels and the horizontal 8 pixels are effective.

Therefore, when performing the decompression process, 0
When the blocks are expanded sequentially, it is checked whether the block is registered in the block information table 704. Then, if the block is registered in the block information table 704, the process of cutting the block to that size is repeated. By controlling in this way, it is possible to obtain a normal image without the image as shown in FIG.

Details of the block division and block information registration control in the above-described embodiment will be described below with reference to the flowcharts shown in FIGS. 8, 9 and 10. First, the process is started in step S801 shown in FIG. Then, in step S802, initialization processing (initialization processing) for initializing various parameters is executed. At this point, it is assumed that the scanner 151 is activated and the image data for one band is stored in the line buffer 105. In the following step S803, “(yb + 1) ×
8 ≦ y size ”, and a loop in the vertical direction (y direction) is checked. In step S803, "y
b ”is the number of blocks in the vertical direction, and is 0 in FIG.
“Yb” is “0”, 1 in the 9th block
In the 0th block to the 19th block, "yb" represents the row number of the vertical block, such as "1". As will be described later, the parameter “xb” indicates the column number of the block in the horizontal direction. For example, 34 blocks have (yb = 3, xb = 4).

As a result of the check in step S803, if the target block does not exceed the y size (the vertical size of the read band), the process proceeds to step S804.
If the target block exceeds the y size, the process proceeds to step S805. The parameter "yc" is 8
It is a loop counter in the vertical direction within a × 8 block.

In step S804, "8" is added to "yc".
Is set and the process proceeds to step S807. On the other hand, in step S805, the "y end flag", which is a parameter indicating the end of the loop in the vertical direction, is turned on. And
At the next step S806, “yc = y size−yb × 8”
Execute and calculate the number of rows to output the actual data. Then, the process proceeds to step S807.

The above steps S803 to S80
When the processing in the vertical direction (y direction) is completed by the processing of 6,
Subsequently, the processing in the horizontal direction (x direction) is executed in the processing of steps S807 to S810. That is, first in step S807, it is checked whether or not “(xb + 1) × 8 ≦ x size”, and a loop in the horizontal direction (X direction) is checked. In step S807, "Xb" represents the digit number of the horizontal block. Step S80
As a result of the check in 7, if the target block does not exceed the x size (horizontal size of the read band), in step S808, the target block is x.
If it exceeds the size, the process proceeds to step S809.

In step S808, "8" is added to "xc".
Is set and the process proceeds to step S811. On the other hand, in step S809, the parameter "x end flag" indicating the end of the loop in the horizontal direction is turned ON. And
In the next step S810, "xc = x size-xbx8"
And calculate the number of digits to output the actual data. Then, the process proceeds to step S811.

The above steps S807 to S81
The processing of 1 ends the processing in the horizontal direction (x direction). Here, the parameter “xc” is a loop counter in the horizontal direction. The above processing will be described below in relation to the actual processing shown in FIG. (Block 34) In FIG. 5, if the block 34 is taken as an example, yb = 3 and xb = 4, so step S80
The condition of “(yb + 1) × 8 ≦ y size” in 3 is
Since “(3 + 1) × 8 ≦ 44” is satisfied, step S8
Go to 04 and set "8" to "yc".

In step S807, "(xb +
The condition of “1) × 8 ≦ x size” is “(4 + 1) × 8 ≦
76 ”is satisfied, the process advances to step S808, and“ x
Set "8" to "c". (Block 50) Considering the case of block 50, yb = 5 and xb = 0, so that step S803 is performed.
Then, the condition of “(yb + 1) × 8 ≦ y size” is “(5
+1) × 8 ≧ 44 ”, and the condition cannot be satisfied. Therefore, the process proceeds to step S805, the“ y end flag ”is turned on, and the process proceeds to step S806. And "yc
= Y size−yb × 8 = 44-40 = 4 ”
Set "4" to "c".

In step S807, "(xb + 1)"
The condition of “× 8 ≦ x size” is “(0 + 1) × 8 ≦ 76”.
Since the condition is satisfied, the process proceeds to step S808, and “xc” is set to “8”. Next, in step S811, a loop determination regarding the vertical direction (y direction) is performed. When the loop ends, the flow proceeds to step S1001 shown in FIG. On the other hand, if it is during the loop, step S90 shown in FIG.
The process proceeds to 1 and it is checked whether or not the counter i is equal to or less than the loop counter xc value which means the end, that is, "i <xc", and this time, the loop in the lateral direction (x direction) is determined. Step S
In the determination of the loop in the x direction of 901, “i <xc”
If it is determined that the process is finished, step S90
When it is determined that the processing is not “i <xc” and the processing is not completed, the processing proceeds to step S902.

In step S902, the line buffer 1
The vertical j and horizontal i pixels (hereinafter referred to as “b (i, j)”) of the target block indicated by 601 of 05 are vertical j and horizontal i positions (hereinafter “B (i, j)” in the block buffer 106). ).). Taking 603 in FIG. 5 as an example, when j = 3 and i = 2, the pixel of b (2,3) indicates the 26th pixel, and the image data at this position is stored in B (2) of the block buffer 106. 2, 3) position (in FIG. 1,
No. 26 of 110).

Further, the data set in step S903 is copied to a buffer p, which is a buffer for temporarily storing, for example, the RAM 102. Then, in step S904, 1 in the jth row in the block
Similarly, for example, a RAM for storing data for rows
The data is also copied to the line buffer 1 provided in 102. The line buffer 1 has a data area for 8 pixels. For example, when the pixel b (2,3) 603, that is, the 26th pixel is processed, the 24th, 25th, and 26th pixels are stored in the line buffer l. Then, in step S905, the counter i is incremented, and the process proceeds to step S901 to determine a loop in the x direction.

In step S901, the counter i is "xc".
When it becomes above, it progresses to step S906, and it is determined whether the counter i is "8" or less, ie, whether the counter i has become "8". This is for determining whether eight pixels have been output in the horizontal direction of the block. Then, in step S907, the buffer p is read to write the read data to the corresponding position of the block buffer 106, and in the following step S908, the same read data is written to the buffer l. Then, in step S909, the counter i is incremented. This step S906
The loop from step S909 is a processing part that outputs dummy pixels instead of outputting existing pixels.

For example, taking 603 in FIG. 5 as an example, since the value of the loop counter xc is "4" here, the loop of steps S901 to S905 is set to four.
Repeat times. That is, it is a process of outputting the 0th, 1st, 2nd, and 3rd pixels of 603. At the time when the loop of four times is completed, the third pixel data is stored in the buffer p, and the first, second, third pixels are stored in the line buffer l.

Then, the process proceeds to step S906. Step S
The loop from 906 to step S909 is performed four times. In step S907, the data in the buffer p, that is, the data of the third pixel is read, and the block buffer 1
Write to 06. At the time when the loop is completed by this process, the data 0, 1, 2, 3, 3,
Data Nos. 3, 3, and 3 are output to the 0th row of the block buffer. At this time, the same data of the first row is also stored in the line buffer 1 in the process of step S908.

When the loop in the horizontal direction (x direction) is completed, the process proceeds from step S906 to step S910 and the vertical direction (y
Direction) counter j is incremented. And FIG.
Returning to step S811 shown in step S811, it is determined whether or not yc rows of data have been output in the vertical direction. If yc is not "8" (when it is necessary to output a dummy row)
Proceeds to step S1001 shown in FIG.

In step S1001, it is determined whether the counter j is less than [8]. If the counter j is "8" or less, the flow advances to step S1002 to read the data in the line buffer 1 and write it in the block buffer 106. Then, in step S1003, the counter j is incremented and the process returns to step S1001. The loop from step S1001 to step S1003 is repeated until the data of 8 rows is finally stored in the block buffer 106.
Repeated until copied to.

For example, taking 605 shown in FIG. 5 as an example, in this case, since the loop counter yc is "4", the output processing in the horizontal direction (x direction) is repeated for four lines. At this time, 24, 25, 26,
Image data Nos. 27, 28, 29, 30, and 31 are stored. Next, step S1001 to step S10
In the processing of 03, the line buffer 1 is output as a dummy row for four lines. As a result of the above processing, the image data as shown by 605 in FIG.
Will be stored in.

[Block registration] When the loop counter yc or the loop counter xc is not equal to or less than "8" (when it becomes "8"), it means that a dummy row or column has been output. S100
4, the block information table 704 of FIG.
The information of the block whose processing has ended is registered in. Figure 5
In the example shown in 603, “9” is set as the block number,
Then, yc = 8 representing the vertical size and xc = 4 representing the horizontal size are respectively registered. The block number count can be calculated using a parameter that is incremented each time the processing in step S1004 is entered. If yc and xc are both "8", it means that the block conversion is not performed. Therefore, this process is not performed and the process proceeds to step S1005.

In step S1005, the x end flag, which is the end flag in the x direction, is checked. If the x end flag is not ON and the condition is not satisfied, step S1
In step 009, the block number xb in the x direction is incremented, the process proceeds to step S803, and the next block is processed. On the other hand, if the x end flag is ON in step S1005, the flow advances to step S1006 to increment the block number yb in the y direction. And then step S1
At 007, the x end flag is turned off. Then step S
At 1008, the y end flag is checked. If the y end flag is ON, it means that all the blocks have been processed, so that the process proceeds to step S1011 to end all the processes.

If the y end flag is OFF in step S1008, the block number xb in the x direction is set to "0", and the flow advances to step S803 to start the processing of the next block. The above description will be briefly summarized below. According to the flowcharts shown in FIGS. 8 to 10,
The image data stored in the line buffer 105 is divided and transferred to the block buffer 106. At that time, 8 ×
For blocks that do not have a size of 8, add pixels to make a size of 8 × 8. Then, the information is written in the block information table 704.

According to the present embodiment as described above, there is an effect that the compression can be performed even when the size of the image is not an integral multiple of the size of the block when performing the block coding. As a result, resolution conversion processing is performed on the image, and compression can be performed regardless of the size. Further, there is an effect that there is no limitation that the image read into the line buffer 105 has to be an integral multiple of the block size.

[Second Embodiment] In the above description, the case where the block data is encoded (compressed) by the compression / expansion processor 106 and stored in the compression memory 108 is mainly described, and the expansion process is shown in FIG. 6 as an example. It was only explained briefly. However, the present invention is not limited to the above example, and in addition to the above compression processing, the compressed data is expanded and the block buffer 106 to the line buffer 10 are expanded.
5 or a second embodiment according to the present invention capable of both compression and decompression processing for transfer to the RAM 102 will be described below.

Also in the second embodiment, the hardware configuration is exactly the same as that of the first embodiment described above, and the image compression processing is completely the same. Therefore, the description of the above configuration and processing is omitted. Hereinafter, the process of decompressing the compressed data stored in the compression memory 108 in the processes of FIGS. 8 to 10 will be described below with reference to the flow chart of FIG.

When the decompression process is selected, the process proceeds to the process of FIG. 11, and the decompression process is started in step S1101. First, in step S1102, various parameters are initialized and the compression / expansion processor 107 is initialized. The data to be compressed in the subsequent step S1103 is the compression memory 10
Check whether it exists in 8. If the data to be compressed does not exist in the compression memory 108, it means that all blocks have been decompressed or there is no data from the beginning, so the process ends in step S1111.

On the other hand, the data to be compressed is the compression memory 10
If it is 8, the compression / expansion processor 107 is activated and the process proceeds to step S1004 to read one block of compressed data from the compression memory 108 and decompress it, and write this decompressed data in the block buffer 106. At this point, it is not known if the data in the block buffer 106 is the block that was transformed during compression (including the extra image). Therefore, in step S1105, the block information table 704 is searched to check whether the block currently being processed is registered. If it does not exist in the block information table 704 in step S1106, the process proceeds to step S1110 and 8 × 8 of the entire block buffer.
All pixels of RAM 102 (or line buffer 105
"The same shall apply hereinafter.").

In step S1106, if the block currently being processed is registered in the block information table 704, the process advances to step S1107, and the effective number of pixels in the horizontal direction and the vertical direction in the block information table 704 are set. Read the number of pixels. Then, in step S1108, the number of effective pixels is copied from the image data stored in the block buffer 106 to a predetermined address of the RAM 102. And step S1109
The block number for identifying the block currently being processed is incremented. Then, step S1103
Proceed to and start processing the next block.

The above processing is repeated until there is no compressed data. As a result, the extra image as shown by 502 in FIG. 6 is deleted, and only the desired image shown by 501 can be obtained. As described above, according to the second embodiment, it is possible to perform compression / expansion when performing block coding even when the size of the image is not an integral multiple of the size of the block. As a result, resolution conversion processing is performed on the image, and compression and expansion can be performed regardless of the size. Also,
There is also an effect that there is no restriction that the image read into the line buffer 105 must be an integral multiple of the block size.

[Third Embodiment] FIG. 7 in the above embodiment.
The block information table 704 shown in FIG.
Since the size changes according to the data read by
The capacity of the header 701 is variable. Therefore, depending on the compression method, in the third embodiment, when the header is not variable length or there is no header, the block information table 704 may be configured to store the block information as data different from the compressed data. Good.

In the above description of each embodiment, the case where the image data read by the scanner 151 is used as the input image data has been described, but the processed image data is not limited to the above example, and other image data is used. Image data from a host computer or the like, image data from another device, data from a personal computer communication or the like, or image data obtained by facsimile communication may be used. This source and the like are not limited at all.

Further, the compressed data may be received from another device by data communication facsimile communication or the like, or may be read via a magnetic disk or the like. Similarly, the source of the compressed data is not limited at all. Alternatively, any source may be used as long as the compressed data and the block information data table are input together.
The present invention may be applied to a system including a plurality of devices or an apparatus including one device.

Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0055]

As described above, according to the present invention, it is possible to perform encoding or decoding even when the size of the image is not an integral multiple of the size of the block.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a scanning direction of a document in a scanner.

FIG. 3 is a diagram in which a document read by a scanner is divided into band units.

FIG. 4 is a diagram illustrating an example of image reading when scanning a document.

FIG. 5 is a diagram for explaining control for dividing a read image into blocks in the present embodiment.

FIG. 6 is a diagram showing an output example when the converted block data in this embodiment is expanded as it is.

FIG. 7 is a diagram showing a configuration example of a block information table according to the present embodiment.

FIG. 8 is a flowchart for explaining details of compression processing according to the present embodiment.

FIG. 9 is a flowchart for explaining details of compression processing according to the present embodiment.

FIG. 10 is a flowchart for explaining details of compression processing according to the present embodiment.

FIG. 11 is a flowchart for explaining decompression processing according to the second embodiment of the present invention.

[Explanation of symbols]

 101 CPU 102 RAM 103 ROM 104 Scanner Interface 105 Line Buffer 106 Block Buffer 107 Compression / Expansion Processor 108 Compression Memory 109 Bus 110 Block Buffer 151 Scanner 203, 204, 402 Sensor 401 Original 403 Line Buffer 701 Header 702 Compressed Data 703, 704 Block Information table

Claims (6)

[Claims] 1. An image having a size of M × N is divided into blocks having a size of m × n, the size of the image smaller than m × n is stored, and the m × n image is stored. An image processing method comprising reconstructing an image having a size less than the above into an m × n size, arranging the reconstructed block to be identifiable, and encoding the m × n block. 2. An image reconstructed by decoding the encoded image into m × n blocks, identifying the reconstructed block, and decoding the reconstructed image according to the size of the stored reconstructed block, and reconstructing the image M × N. An image processing method characterized in that the image is restored to an image of the size. 3. An image having a size of M × N is divided into blocks having a size of m × n, and the size of the image smaller than m × n is stored. Image having a size less than the above is reconstructed to have a size of m × n, the reconstructed block is configured to be identifiable, the m × n block is encoded, and the encoded image is resized to m × n.
And reconstructing a block according to the size of the stored reconstructed block to restore the reconstructed image into an image of size M × N. Image processing method. 4. A dividing unit for dividing an image having a size of M × N into blocks having a size of m × n, and a size of an image having a size smaller than m × n divided by the dividing unit. A first reconstructing unit for reconstructing an image of a size smaller than m × n divided by the dividing unit into a size of m × n, and m × divided by the dividing unit. n blocks and the first
And an encoding unit that encodes the m × n blocks reconstructed by the reconstructing unit. 5. Decoding means for decoding the encoded image into m × n blocks, identification means for identifying reconstructed blocks, and decoding according to the size of the reconstructed blocks identified by the identification means. Image processing including a second reconstructing unit for reconstructing the reconstructed image and a reconstructing unit for reconstructing the image reconstructed by the second reconstructing unit into an image of size M × N. apparatus. 6. A dividing means for dividing an image having a size of M × N into blocks having a size of m × n, and a size of an image having a size smaller than m × n divided by the dividing means. A first reconstructing unit for reconstructing an image of a size smaller than m × n divided by the dividing unit into a size of m × n, and m × divided by the dividing unit. n blocks and the first
Encoding means for encoding the m × n blocks reconstructed by the reconstructing means, decoding means for decoding the image encoded by the encoding means into m × n blocks, and reconstructing by the first reconstructing means. The identification means for identifying the selected block, the second reconstruction means for reconstructing the image decoded by the decoding means according to the size of the reconstruction block stored in the storage means, and the second reconstruction means. An image processing apparatus, comprising: a restoration unit that restores a reconstructed image into an image having a size of M × N.