JPH09214777A - Image expansion processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To edit a large scale image even with a memory configuration of a small capacity by executing expansion processing only for a designated rectangular area with respect to compression data of one page. SOLUTION: An expansion start coordinate STX and an expansion end coordinate ENX with respect to a main scanning direction are set to a rectangular area being a segmentation object of an original image. Then a change point coordinate of input change point data CPOSB and the expansion start coordinate STX are compared and when the change point coordinate is less than the expansion start coordinate STX, the coordinate is set at the outside of objects of expansion processing and change point coordinates with a relation of the CPOSB > the STX are used for change point coordinates to be converted for the image data. Then the image data as to the designated area designated by the expansion start coordinate STX and the expansion end coordinate ENX are generated from the input change point data CPOSB consisting of change point coordinate information strings to white or black level picture elements in the main scanning direction of one line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image expansion technique, and more particularly to MH (Modified Huffman) / MR (Modi).
The present invention relates to an image expansion processing method for expanding an image of a fied READ) / MMR (Modified Modified READ) code.

[0002]

2. Description of the Related Art Generally, MH (Modified Huffman) / MR is used as a data compression method for a binary image.
(Modified READ) / MMR (Modified Modified REA
D) There is an encoding method.

Based on the compressed data of a binary image image obtained by the MH / MR / MMR encoding method or the like, FIG.
As shown in FIG. 2, in order to cut out the image of the partial rectangular area in the original image, the conventional image expansion processing method is performed as follows.

That is, a work memory (work area) for one page of image data to be cut out of an image is prepared on the memory, and the entire image for one page is expanded based on the compressed data. Then, the image of the target rectangular area is output from the image data of one page expanded in the working memory to the output image area, and the image cutting is completed.

[0005]

As described above, according to the conventional image decompression processing method, in order to obtain an image of a specific rectangular area in the original image based on the compressed data, the compressed data is once extracted. It was necessary to expand the entire image for one page on the working memory. Therefore, the time required to cut out the required image is the total of the time required to decompress the image for one page and the time required to cut out the image of a specific rectangular area from the developed entire image. Therefore, the responsiveness until obtaining the output image is poor.

Further, when the target image is a large image having a size of A0 and a resolution of 16 lines / mm, for example, when the compressed image is expanded at one time, the data amount becomes about 30 Mbyte, which is large. It requires a large amount of working memory.

The present invention has been made in consideration of the above-mentioned circumstances, and at a high speed, a partial cutout of a rectangular area in an entire image is performed based on compressed data without using a large capacity work memory. An object is to provide a possible image decompression processing method.

[0008]

DISCLOSURE OF THE INVENTION According to the present invention, a decompression start coordinate in image data, which is an object of image decompression based on a coordinate sequence of change points to a white pixel and a black pixel in the main scanning direction of the image data. And expansion end coordinates are set, and by comparing the change point coordinates sequentially read in the raster scanning direction with the expansion start coordinates, the start change point coordinates of the range to be expanded in the image data is detected, and raster scanning is performed. By comparing the change point coordinates sequentially read in the direction and the expansion end coordinates, the change point coordinates at the end of the range to be expanded in the image data are detected, and the detected change point coordinates from the end change point coordinates are detected. For the change point coordinates in the change point coordinate sequence up to the point coordinates, obtain the quotient and the remainder value divided by a predetermined value, and calculate the difference between the obtained quotient and the quotient obtained for the immediately preceding change point coordinate. Seeking, difference When the value is 0, the image pattern for the change point coordinate sequence that does not reach the predetermined value is obtained according to the remainder value, and when the obtained difference value is 1 or more, for the change point coordinate sequence that does not reach the predetermined value, The image pattern obtained by the above is used as an image pattern after image expansion, and an image pattern in which white pixels or black pixels are continuous according to the obtained difference is output as the image pattern after image expansion.

Further, according to the present invention, a decompression start coordinate in image data, which is an object of image decompression based on compressed data encoded by a one-dimensional encoding method including an EOL code indicating a line segment of an image, and While setting the decompression end coordinate and detecting the EOL code from the compressed data, it is determined whether or not the line corresponding to the code data is the object of image decompression based on the decompression start coordinate and the decompression end coordinate, and the image decompression is performed. When it is determined that the line is the target line, the code data is converted into a change point coordinate sequence to white pixels and black pixels, and for this change point coordinate information sequence,
Obtain the quotient and the remainder value divided by a given value, find the difference between the quotient obtained and the quotient obtained for the coordinates of the immediately preceding change point, and reach the given value when the obtained difference value is 0. The image pattern for the changing point coordinate sequence is obtained according to the remainder value, and when the obtained difference value is 1 or more, the image pattern obtained for the changing point coordinate sequence that does not reach the predetermined value is the image after image expansion. It is characterized in that an image pattern in which white pixels or black pixels corresponding to the obtained difference is continuous is output as an image pattern after image expansion.

Further, according to the present invention, the decompression start coordinates and decompression end coordinates in the image data, which are objects of image decompression based on the compressed data coded by the two-dimensional coding method, are set and The code data is sequentially read out and converted into a sequence of change point coordinates for white pixels and black pixels,
It is determined whether or not the line of the image data corresponding to the change point coordinate sequence is the target of image expansion based on the expansion start coordinates and the expansion end coordinates, and it is determined that the line is the target of image expansion. Sometimes, for the change point coordinate information sequence, the quotient and the remainder value divided by a predetermined value are obtained, the difference between this quotient and the quotient obtained for the immediately preceding change point coordinates is obtained, and the obtained difference value When 0 is 0, the image pattern for the change point coordinate sequence that does not reach the predetermined value is obtained according to the remainder value, and when the obtained difference value is 1 or more, for the change point coordinate sequence that does not reach the predetermined value, The obtained image pattern is used as an image pattern after image expansion, and an image pattern in which white pixels or black pixels are continuous according to the obtained difference is output as the image pattern after image expansion.

Further, according to the present invention, the EOL code indicating the line division of the image and the code type in which the code data encoded by the one-dimensional encoding method and the code data encoded by the two-dimensional encoding method are mixed. Is added to the image data based on the compressed data including the additional information indicating the expansion start coordinate and the end start coordinate in the image data, and the EOL code and the additional information are detected from the compressed data. Based on the information, it is determined whether the code data of the line of interest is based on the one-dimensional coding system or the two-dimensional coding system. From this determination result, if the line of interest is code data based on the one-dimensional coding system, ,
The line corresponding to the code data from the decompression start coordinate-1 to the end start coordinate is determined to be the target of image decompression, and the change point coordinate sequence from the corresponding code data to the white pixel and the black pixel is generated. If the line of interest is code data by the two-dimensional encoding method, the line corresponding to the code data from the decompression start coordinates to the end start coordinates is determined as the object of image decompression, and white pixels and black pixels are extracted from the corresponding code data. Generate a change point coordinate sequence to a pixel, find the quotient and the remainder value divided by a predetermined value from the generated change point coordinate information sequence, and find the obtained quotient and the immediately preceding change point coordinate. The difference between the calculated quotient and the quotient is 0. When the calculated difference is 0, the image pattern for the change point coordinate sequence that does not reach the predetermined value is calculated according to the remainder value, and when the calculated difference is 1 or more, To a predetermined value Do not output the image pattern obtained for the change point coordinate sequence as the image pattern after image decompression, and output the image pattern in which white pixels or black pixels continue according to the obtained difference as the image pattern after image decompression. Characterize.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a system that realizes an image expansion processing method according to this embodiment. As shown in FIG. 1, this system is C
The PU 10, the RAM 12, the VRAM 14, the ROM 16, the input device 18, the input control unit 20, the display device 22, the display control unit 24, the storage device 26, and the storage control unit 28.

The CPU 10 controls the entire apparatus, and accesses the RAM 12, the VRAM 14, and the ROM 16 and activates a program according to an input instruction to realize the function of the image expansion processing method according to the present invention.

The RAM 12 is a program area 12 in which various processing programs for determining the operation of the CPU 10 are stored.
In addition to a, a work area 12b as a working memory for storing various variables used when performing image processing, a table, compressed data to be processed, and the like are provided.

The VRAM 14 is an area for expanding display data to be displayed on the display device 22. VR
The display data expanded in the AM 14 is read by the display control unit 24 and provided for display on the display device 22.

The ROM 16 is a program area 16 in which various processing programs for determining the operation of the CPU 10 are stored.
a, a data area 16b for storing various data, and the like are provided.

The input device 18 is composed of a keyboard, a mouse or the like, and inputs an instruction to the system. The display device 22 is composed of, for example, a liquid crystal display, and performs display under the control of the display control unit 24. The display control unit 24 controls the display on the display device 22, reads the display data stored in the VRAM 14, and provides the display data on the display device 22.

The storage device 26 stores compressed data obtained by encoding the image data to be processed, change point coordinate data, image data, and the like. Storage control unit 28
Controls input / output of data and the like to / from the storage device 26.

Next, a data decompression processing method according to the first embodiment of the present invention will be described with reference to the flowchart shown in FIG. As shown in FIG. 5, the image decompression processing method according to the first embodiment generates image data based on a change point data string (compressed data) including change point coordinate information of white data and black pixels of image data. To do. In this embodiment, only the image of the specified rectangular area is expanded based on the change point data string.

Step A1 is a step of setting the extension start coordinates (STX) and the extension end coordinates (ENX) with respect to the main scanning direction. Step A2 is a step of executing an initialization process, and initializes the immediately preceding change point calculation result.

In step A3, the change point coordinates of the input change point data (CPOSB) sequentially read in the raster direction are compared with the expansion start coordinates (STX), and the change point coordinates are equal to or less than the expansion start coordinates (STX). Is excluded from the target of the decompression process and is discarded, and the change point coordinates serving as the start position of the target of the decompression process with CPOSB> STX are detected. Further, it is a step of comparing the change point coordinates of the input change point data (CPOSB) with the extension end coordinates (ENX), and detecting the change point coordinates of the extension end coordinates (ENX) +1 as the end point of the extension process. .

Step A4 is a step for obtaining the byte length (BYTELEN) of the change point coordinates after partial expansion and the remainder value thereof. The calculation result for the immediately previous change point coordinates is stored in (BYTELEN_OLD), and after the partial designation. The value of the change point coordinate (CPOS) is taken as the value obtained by subtracting the extension start coordinate (STX) from the coordinate of the input change point (CPOSB), and this is divided by a predetermined value to obtain the quotient and the remainder.

In step A5, the difference between the byte length (BYTELEN) of the change point coordinates obtained in step A4 and the immediately preceding value (BYTELEN_OLD) is obtained and held in (FILL_NO).

Step A6 is a step of determining whether or not (FILL_NO) obtained in step A5 is 1 or more. Step A7 is a step of determining whether or not the color of the current change point is black.

Steps A8 and A9 are the fractional value of the byte length (BITPAT_NO) and the current color (COLO).
R) as an address and referring to the image conversion table,
This is the step of obtaining the image pattern (BITPAT_REG) of the fractional part, and when the current color is black, (BI
TPAT_REG) and output of image conversion table
R calculation is performed and the result is substituted into (BITPAT_REG).

On the other hand, if the current color is white, (BITP
AND the output of the image conversion table
The result obtained is substituted into (BITPAT_REG). Step A10 is (FILL_N
O) is a step executed when it is 1 or more, and is a step of transferring the image pattern (BITPAT_REG) of the fractional part generated in steps A8 and A9 to the output image area. Further, (BITPAT_REG) is initialized with the image pattern corresponding to (BITPAT_NO) obtained in step A4.

Step A11 consists of 1 byte (8 in this case).
A white or black image composed of (bit) (FIL
L_NO) -1 step of transferring to the output image area.

Steps A12 and A13 are the end position of expansion,
This is a step of determining the end of one screen, and is for performing sequential processing in the raster scanning direction until the image of the specified rectangular area is cut out based on the change point data string for one screen cut out in the main scanning direction. This is the end judgment.

Next, the operation of the data decompression processing method according to the first embodiment will be described with reference to the specific examples shown in FIGS. 3, 4 and 5. The input change point data shown in FIG. 3C becomes the input data. Image data corresponding to the change point coordinate sequence of FIG. 3C is shown in FIG.
FIG. 3D shows a change point coordinate sequence (change point sequence data after partial designation (CPOS)) corresponding to the area designated by the extension start coordinates (STX) / extension end coordinates (ENX). An image pattern corresponding to the change point sequence data (CPOS) shown in FIG. 3D is shown in FIG. Also, the bit length (B) of the change point obtained in step A3
FIG. 3E shows YTELEN), and FIG. 3F shows the remainder (fraction) obtained by dividing the change point data (CPOS) after partial designation by a predetermined value (here, 8).

FIG. 4 shows a fraction (BITPAT_N) when the image pattern is generated in steps A8 and A9.
The message conversion table stores the bit pattern (8-bit image pattern in this embodiment) accessed by O). In this embodiment, two image conversion tables for a black change point and a white change point are prepared.

FIG. 5 shows a process of converting the input change point sequence data (CPOSB) shown in FIG. 3C into image data. First, the expansion start coordinates (STX) and the expansion end coordinates (ENX) in the main scanning direction of the rectangular area to be cut out in the original image are set.

Next, after the immediately preceding change point calculation result is initialized (step A2), the input change point data (CPOSB) shown in FIG. 3C are sequentially read in the raster direction.
From the extension start coordinate (STX) and extension end coordinate (EN
Based on X), the start of decompression targeted for partial decompression processing
The end position is detected (step A3). That is, the change point coordinates of the input change point data (CPOSB) are compared with the decompression start coordinates (STX). If the change point coordinates are less than or equal to the decompression start coordinates (STX), they are discarded as non-expansion targets. Then, the change point coordinates satisfying CPOSB> STX are set as the change point coordinates to be converted into image data. Further, the extension end coordinate (ENX) +1 coordinate is set as the end of the change point coordinate to be subjected to the extension processing, and the extension end coordinate (EN
X) +1 change point coordinates are not processed.

Input change point data (CPOSB)
The value obtained by subtracting the expansion start coordinate (STX) from the change point coordinate of is set as the change point coordinate of the change point data (CPOS) after the partial designation. As a result, the change point data (CPOS) after designation of the part to be expanded of the currently targeted line as shown in FIG. 3D is obtained.

Next, the immediately preceding calculation result is calculated as (BYTELEN
_OLD) and divides the change point coordinates of the change point data (CPOS) by a predetermined value (byte length (BY
TELEN)) and the remainder (BITPAT_NO) are calculated (step A4). In the present embodiment, the predetermined value is set to 8 and the byte length (BYTELEN) and the remainder (BITPAT_NO) of the change point coordinates are calculated. That is, with (POSSHIFT) = 3, the input change point data (CPOS) is shifted to obtain the quotient, and (POSMFT)
ASK) = 7 and the remainder is obtained by the logical product of the input change point data (CPOS).

Next, the byte length (BYTELEN) of the change point coordinates obtained in step A4 and the immediately preceding value (BYT).
ELEN_OLD) and calculate this as (FILL_OLD)
NO) (step A5).

If (FILL_NO) is 0 (step A6), the process proceeds to step A7. In step A7, it is determined whether or not the color of the current change point is black. When the color of the current change point is black, the image pattern (BITPAT_REG) of the previous fractional part and FIG.
By ORing the image pattern obtained from the image conversion table for black shown in (1), (B
ITPAT_REG) is generated (step A8).

When the color of the current change point is white, the image pattern (BITPAT_R) of the previous fractional part is displayed.
EG) and the image pattern obtained from the image conversion table for white shown in FIG. 4B are ANDed to generate (BITPAT_REG) (step A9).

In this embodiment, the fraction (BITPA
The image conversion table accessed by (T_NO) is provided with a white change point and a black change point, but two tables are not necessarily required because they are obtained by bit inversion. That is, the image pattern obtained from one of the tables is inverted and used to substitute for the other table. Further, in the present embodiment, the table stores an 8-bit image pattern, but a table configuration of 16 bits / 32 bits or the like is used depending on the unit of expansion in the output image area. The image pattern stored in the image conversion table is, for example, for black, and is a pattern in which after the number of continuous white pixels indicated by the fraction (BITPAT_NO), the black pixels of the remaining pixels are continuous.

On the other hand, in step A6, step A
When it is determined that (FILL_NO) obtained in 5 is 1 or more, the fractional image pattern (BITPAT_REG) generated in steps A8 and A9 is used as the final image pattern generated based on the change point data. Transfer to the output image area (step A10). Also,
(BITPAT_REG) is processed in step A4 for processing (steps A8 and A9) for the next change point data.
The image pattern is initialized with the image pattern obtained from the image conversion table corresponding to (BITPAT_NO) obtained in step 1.

Then, the 8-bit white or black image is transferred to the output image area for (FILL_NO) -1 times. That is, if (FILL_NO) is 2 or more, it indicates that the same color of white or black is continuous for 1 byte or more, so that the required number of bytes of white or black data is continuously output. .

If the line end has not been reached,
Returning to the process of step A3, the process is repeated for the remaining part of the change point data (CPOS) after the partial designation of the target line. If the end of the line has been reached and the processing for one screen has not been completed, the process returns to the initialization processing in step A2 and the processing is performed on the input change point data of the remaining lines. When the processing for all lines is completed, the processing ends.

In the example shown in FIG. 5, first, (FILL_N
The calculation of the fractional part is performed until O) becomes 1 or more. In this example, the input change point data (CPOS) is between 5 and 7,
As shown in FIG. 3E, the byte length (BYTEL
Since EN) is 0, the operation for the fractional part is performed.

When the input change point data (CPOS) = 5,
Fraction (BITPAT_NO) is 5 (change point to black pixel)
Therefore, the image pattern of the fractional part (BITPAT
_REG) is the image conversion table value for black (0x07) corresponding to (BITPAT_NO) = 5, that is, BIPTAT (BITP corresponding to CPOS shown in FIG.
AT_NO).

When the input change point data (CPOS) = 6,
Since the fraction (BITPAT_NO) is 6, which is the change point to the white pixel, the table value (0xf) of (BITPAT_NO) = 6 obtained from the image conversion table for white.
c) and the image pattern of the previous fractional part (BITPAT
AND with (_REG) (BITPAT_RE
G) is obtained (step A9).

When CPOS = 7, since the color of the changing point is black, it is obtained from the image conversion table for black (BI
An image pattern corresponding to TPAT_NO) = 7,
The image pattern of the previous fractional part (BITPAT_RE
(BITPAT_REG) is obtained by taking an OR with G) (step A8).

When CPOS = 9 (change point to white pixel),
Since the byte length (BYTELEN) = 1, (FILL_NO) = 1 is obtained in step A5. Therefore, the value of (BITPAT_REG) obtained immediately before is transferred to the output image area. In addition, (BITPA
From T_NO) = 1, the image conversion table for white is referred to and substituted for (BITPAT_REG) (step A
10).

Hereinafter, the same calculation can be performed up to CPOS = 15. When CPOS = 24 at the final change point, the previous byte length (BYTELEN_OLD) = 1 and the byte length (BYTELEN) (FILL).
_NO) = 2. Therefore, in step A10, after the immediately preceding (BITPAT_REG) is output,
ILL_NO) -1 byte data, that is, a 1-byte black image pattern is output. Depending on the input change point data (image pattern) to be processed,
Here, a white image pattern is output.

In this way, the input change point data (CPOSB) consisting of the change point coordinate information sequence for white pixels and black pixels in the main scanning direction of the image pattern for one line.
From the extension start coordinate (STX) and extension end coordinate (EN
The image data for the designated area designated by X) can be generated.

In the image decompression processing method of the first embodiment, the change point coordinates other than the designated area are not subject to decompression processing (not converted into image data), so the processing time is shortened accordingly. Further, since an image outside the designated area is not generated, no extra working memory is required.

Next, a data decompression processing method according to the second embodiment of the present invention will be described with reference to the flowchart shown in FIG. The image expansion processing method according to the second embodiment expands only the portion specified by the rectangular area from the compressed data in the output image area for the image data compressed by the MH encoding method.

Step B1 is a step of the initialization process, which is the extension start coordinate (STX.S) in the main scanning / sub scanning direction.
TY) and end coordinates (ENX.ENY). Also, the count value LCNT of the processing line counter for managing the line to be processed is initialized. However, STX = main scanning extension start coordinate, STY = sub scanning extension start coordinate, ENX = main scanning extension end coordinate, and ENY = sub scanning extension end coordinate.

Step B2 is a step of detecting an EOL (End Of Line) code from the compressed code by the MH coding method. Step B3 is a step of determining whether or not the line to be processed at present is within the expansion processing area, and whether or not the count value LCNT of the processing line counter is equal to or greater than the set expansion start position. Judge by

Step B4 is one line of coded data (compressed data) when the line to be processed is determined to be within the expansion processing area in step B3.
Is a step of converting a change point coordinate sequence (change point data) into white pixels or black pixels, that is, a change point table.

Step B5 is a step of performing a partial expansion process in the main scanning direction in the above-described first embodiment on the change point coordinate sequence obtained in step B4, in which the image output area is partially expanded. The decompression result is output.

Step B6 is a step of incrementing the count value LCNT of the processing line counter by +1. Step B7 is a step of ending the processing when the processing line count value reaches the extension end line.

Next, the operation of the data decompression processing method according to the second embodiment will be described by showing a specific example. Figure 7
Indicates the MH-encoded compressed data (code data string) for one page, and EOL in FIG. 7 is a code word indicating the line end of each line. However, this code word EOL is also added before the first data line of one page.

DATA indicates code data for one line, DATA1 is code data for the first line, and in the figure, indicates that it is N page compressed data.

First, as initialization processing, for example, compressed data of an image of 100 dots × 100 lines
Decompression start coordinates (S
TX. STY) is set to (X.Y) = (10.1), and decompression end coordinates (ENX.ENY) is set to (X.Y) = (50.5).
0) is set (step B1). The upper left coordinate of the image is the origin (X.Y) = (0.0)
And

Next, the EOL code is detected from the compressed data (step B2). Here, since the count value LCNT of the processing line counter is 0 and the value of the sub-scanning expansion start coordinate STY is 1, it is assumed that the line currently being processed is outside the expansion processing region and the first line The code data (DATA1) is skipped (steps B2 and B3). Then, the count value LCNT of the processing line counter is incremented by +1 and the process returns to the next EOL code detection process (steps B6 and B7).

Next, when the EOL code is detected, the value of the expansion start coordinate STY in the sub-scanning direction is 1, and the count value LCNT of the processing line counter is 1, so that
Assuming that the second line to be processed is within the decompression processing target, the code data (DATA
2, DATA3, ...) is converted into a sequence of change point coordinates (change point data) into white pixels or black pixels (step B).
4). The compressed code (code data) according to the MH coding method is a one-dimensional code, and black run and white run are represented by a predetermined code, and therefore, change to a white pixel or a black pixel according to the code. Convert to a point coordinate sequence.

Next, 1 generated in step B4
The image is expanded by the image expansion processing method described in the first embodiment based on the change point coordinate sequence included in the specified expansion processing area (X-direction coordinate values 10 to 50) in the change point data for the line. A pattern is generated and output as decompressed image data in the output image area (step B5).

As described above, the count value L of the processing line counter
The process is repeated until the CNT reaches the decompression end line coordinate (Y = 50), and the process for the compressed data after reaching the decompression end position is not performed. As a result, it is possible to generate (decompress) only the image in the specified rectangular area from the compressed data.

In this way, for the first line included in the decompression processing area, that is, for the compressed data up to the decompression start line, only the processing for detecting the EOL code is required, and after the decompression end line. Since no processing is performed on the compressed data of, the processing time is shortened accordingly.

Moreover, since the image outside the designated rectangular area is not generated, the time required for the decompression process is shortened and no extra working memory is required. Next, regarding the data expansion processing method according to the third embodiment of the present invention,
This will be described with reference to the flowchart shown in FIG. In the data decompression processing method according to the third embodiment, with respect to the image data compressed by the MMR encoding method as shown in FIG. 9, only the portion designated by the rectangular area from the compressed data is expanded in the output image area.

Step C1 is a step of the initialization process, which is the extension start coordinate (STX.S) in the main scanning / sub scanning direction.
TY) and end coordinates (ENX.ENY). Also, the count value LCNT of the processing line counter is initialized. However, STX = main scanning extension start coordinate, STY =
Sub-scan decompression start coordinates, ENX = main-scan decompression end coordinates, E
NY = subscanning decompression end coordinate.

In step C2, an MMR code, which is two-dimensional code data, is sequentially read from the area where the compressed data is stored, and a line of change point coordinates (change point data) from this code data to white pixels and black pixels for one line. ), That is, a step of generating a change point table. Further, in the third embodiment, when decompressing the two-dimensional encoded data, the change point coordinates of the current line are generated based on the change point coordinate information of the previous line.

Step C3 is a step of determining whether or not the target line to be processed is in the expansion processing area, and it is determined whether the processing line count value is equal to or greater than the set expansion start position.

Step C4 is a step of performing partial expansion processing in the main scanning direction of the image expansion processing method in the first embodiment on the change point coordinate information obtained in step C2. Here, for the image output area. The result of partial decompression processing is output.

Step C5 is a step of incrementing the count value LCNT of the processing line counter by +1. Step C6 is the processing line count value LCNT.
Is a step of ending the processing when reaches the decompression end line.

A specific example of partial expansion in the main scanning direction is performed in the same manner as in the first or second embodiment, and detailed description thereof will be omitted. The difference between the third embodiment and the second embodiment is that, as shown in FIG. 9, since the compressed data to be processed is the MMR code which is a two-dimensional code, the line like the EOL code is used. The point is that the code indicating the end is not included.

In the third embodiment, in step C2, the compressed data from the first line is converted into change point coordinate information, and in step C3, the number of lines is counted from the change point coordinate information. In addition, EOFB shown in FIG.
The code is a facsimile block termination code and is a code word indicating the end of one page.

The change point coordinate information generated in step C2 is used only to generate the change point coordinates of the next line until it enters the designated expansion processing area, and the image is not expanded. That is, in the MMR encoding method, the encoding is performed based on the relative position of the change point coordinate to the white pixel or the black pixel in the main scanning direction and the change point coordinate to the white pixel or the black pixel on the next line. So, according to the code directly without decompressing the image,
The change point coordinates of the next line can be generated.

In this way, the change point coordinate information only needs to be generated for the compressed data up to the decompression start line, and the compressed image after the decompression end line is not processed at all. Processing time is reduced.

Moreover, since the image outside the designated rectangular area is not generated, the time required for the decompression processing is shortened and no extra working memory is required. Next, regarding the data decompression processing method according to the fourth embodiment of the present invention,
This will be described with reference to the flowchart shown in FIG.
In the data decompression processing method according to the fourth embodiment, with respect to the image data compressed by the MR encoding method as shown in FIG. 11, only the portion designated by the rectangular area from the compressed data is expanded in the output image area.

FIG. 11 shows compressed data for one page of an image compressed by the MR coding method. In FIG. 11, EOL is a code word indicating the line end of each line, and is added to the end of all encoded lines. Further, after the EOL code, an additional bit (Tag) indicating whether the code compressed by the one-dimensional coding method or the two-dimensional coding method is used in the next line. When Tag = 1, the next line is 1.
Dimensional coding, and when Tag = 0, the next line indicates two-dimensional coding. However, the code word of EOL + Tag is also added before the first data line of one page.

Step D1 is a step of the initialization process, which is the extension start coordinates (STX.S) in the main scanning / sub scanning direction.
TY) and end coordinates (ENX.ENY). Also, the processing line counter LCNT is initialized. However, STX = main scanning extension start coordinate, STY = sub scanning extension start coordinate, ENX = main scanning extension end coordinate, and ENY = sub scanning extension end coordinate.

Step D2 is a step of sequentially reading the code data from the area where the compressed data is stored and determining whether the code following the code is a one-dimensional code or a two-dimensional code. In the fourth embodiment, an additional bit (T
When ag) is 1, it is determined as one-dimensional encoding, and when the additional bit is 0, it is determined as two-dimensional encoding.

Step D3 is a step that is executed when the result of determination in step D2 is a two-dimensional code, and a change point coordinate string (change point table) from the code to one line of white pixels and black pixels. To generate. Also, the fourth
In the embodiment, when decompressing the two-dimensional code, the change point coordinates of the current line are generated based on the change point coordinate information of the previous line.

Step D4 is a step that is executed when the result of determination in step D2 is a one-dimensional code, and the processing line counter value LCNT is greater than or equal to the set decompression start line coordinate (STY) -1. Or not.

Step D5 is a step of generating a change point coordinate string (change point table) from the compressed data to one line of white pixels and black pixels based on the determination result of step D4. If it is outside the specified expansion processing area, the code data is skipped.

Step D6 is a step of determining whether or not the count value LCNT of the processing line counter is equal to or larger than the set expansion start line coordinates. Step D
Step 7 is a step of performing the partial expansion processing in the main scanning direction described in the first embodiment on the change point coordinate information sequence (change point table) obtained in step D3 or step D5. The partial decompression result is output for.

Step D8 is a step of incrementing the count value LCNT of the processing line counter by +1. Step D9 is a step of ending the processing when the count value LCNT of the processing line counter reaches the extension end line.

Next, the operation of the data decompression processing method according to the fourth embodiment will be described by taking the compressed data shown in FIG. 11 as an example. First, in the step of the initialization processing, after setting the expansion start coordinates (STX.STY) and the end coordinates (ENX.ENY) in the main scanning / sub scanning direction, the code data of the compressed data is read out and is followed by the EOL code. By referring to the additional bit (Tag), it is determined whether the code that follows is a one-dimensional code or a two-dimensional code (step D2).

In the case of a two-dimensional code, the change point coordinates of the current line currently being processed are generated based on the change point coordinate information of the previous line based on the MR coding method (step D3).

On the other hand, in the case of a one-dimensional code, if the processing line counter value LCNT is greater than or equal to the set decompression start line coordinate (STY) −1, white and black pixels for one line from the compressed data A change point coordinate sequence (change point table) is generated (step D5).

That is, when the two-dimensional coded data starts from the decompression start line coordinate position, the change point coordinate information of the previous line is required when converting the two-dimensional coded data into the change point coordinate information. Therefore, in the fourth embodiment, when it is determined that the code is a one-dimensional code, the decompression start line coordinate is 1
Change point coordinates are generated before the line.

In the same manner as in the third embodiment, the decompression processing is performed in the same manner as in the first embodiment based on the change point table generated while the processing line counter value LCNT indicates the inside of the decompression area. As a result, it is possible to generate an image of only the specified rectangular area from the compressed data in which the one-dimensional code data and the two-dimensional code data by the MR encoding method are mixed and output the image to the image output area.

As described above, in the fourth embodiment, it is only necessary to detect the EOL code or generate the change point coordinate information for the compressed data up to the decompression start line, and the compressed image after the decompression end line. Does not perform any processing, the processing time is shortened accordingly. Moreover, since the image outside the designated rectangular area is not generated, the time required for the decompression processing is shortened and an extra working memory is not required.

[0089]

As described above in detail, according to the present invention, 1
By decompressing only the specified rectangular area for the compressed data of one page, high-speed image expansion becomes possible, there is no need to expand the entire image of one page, and even if the memory configuration of small capacity is large. You can edit the image.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a system that realizes an image expansion processing method according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining a data expansion processing method according to the first embodiment.

FIG. 3 is a diagram showing an image generation process for explaining the operation of the data expansion processing method according to the first embodiment.

FIG. 4 is a diagram showing an example of an image conversion table in the first embodiment.

FIG. 5 is a diagram showing an image generation process for explaining the operation of the image expansion processing method according to the first embodiment.

FIG. 6 is a flowchart for explaining a data expansion processing method according to the second embodiment.

FIG. 7 is a diagram showing MH-encoded compressed data for one page which is a processing target in the second embodiment.

FIG. 8 is a flowchart for explaining a data expansion processing method according to the third embodiment.

FIG. 9 is a diagram showing MMR-encoded compressed data for one page which is a processing target in the third embodiment.

FIG. 10 is a flowchart for explaining a data expansion processing method according to the fourth embodiment.

FIG. 11 is a diagram showing MR-encoded compressed data for one page which is a processing target in the fourth embodiment.

FIG. 12 is a diagram for explaining conventional image expansion processing.

[Explanation of symbols]

 10 ... CPU 10 12 ... RAM 14 ... VRAM 16 ... ROM 18 ... Input device 20 ... Input control unit 22 ... Display device 24 ... Display control unit 26 ... Storage device 28 ... Storage control unit

Claims (4)

[Claims] 1. A decompression start coordinate and an decompression end coordinate in the image data, which are targets of the image decompression based on a coordinate sequence of change points to white pixels and black pixels in the main scanning direction of the image data, are set, The change point coordinates of the beginning of the range to be expanded in the image data are detected by comparing the change point coordinates sequentially read in the raster scan direction with the expansion start coordinates, and the change sequentially read in the raster scan direction. The change point coordinates at the end of the range to be expanded in the image data are detected by comparing the point coordinates with the expansion end coordinates, and the change point coordinates from the detected start change point coordinates to the end change point coordinates are detected. For the change point coordinates in the row, find the quotient and the remainder value divided by a predetermined value, find the difference between this quotient and the quotient found for the immediately preceding change point coordinates, and find the difference value When 0, the predetermined The image pattern for the change point coordinate sequence that does not reach is obtained according to the remainder value, and when the obtained difference value is 1 or more, the image pattern obtained for the change point coordinate sequence that does not reach the predetermined value is decompressed. And an image pattern in which white pixels or black pixels corresponding to the obtained difference are consecutively output as an image pattern after image expansion. 2. A decompression start coordinate and an decompression end coordinate in the image data, which are targets of image decompression based on compressed data encoded by a one-dimensional encoding method including an EOL code indicating a line segment of an image. Is set, while detecting the EOL code from the compressed data, it is determined whether the line corresponding to the code data is the target of image expansion based on the expansion start coordinate and the expansion end coordinate, and the target of image expansion is determined. When it is determined that the line is a line, the code data is converted into a change point coordinate sequence to white pixels and black pixels, and a quotient and a remainder value obtained by dividing the change point coordinate information sequence by a predetermined value are obtained. The difference between the obtained quotient and the quotient obtained for the immediately preceding change point coordinate is obtained, and when the obtained difference value is 0, the image pattern for the change point coordinate sequence that does not reach the predetermined value is left over. When the value of the calculated difference is 1 or more, the image pattern obtained for the change point coordinate sequence that does not reach the predetermined value is the image pattern after image expansion, and the white An image expansion processing method comprising outputting an image pattern in which pixels or black pixels are continuous as an image pattern after image expansion. 3. The decompression start coordinates and decompression end coordinates in the image data, which are the objects of image decompression based on the compressed data encoded by the two-dimensional encoding method, are set, and the code data is converted from the compressed data. It is sequentially read and converted into a change point coordinate sequence to white pixels and black pixels, and whether the line of the image data corresponding to this change point coordinate sequence is an object of image extension is determined by the extension start coordinate and extension end. When it is determined based on the coordinates and it is determined that the line is the target of image decompression, the quotient and the remainder value obtained by dividing the change point coordinate information sequence by a predetermined value are obtained, and the obtained quotient and the previous change The difference between the point coordinate and the calculated quotient is calculated. When the calculated difference is 0, the image pattern for the change point coordinate sequence that does not reach the specified value is calculated according to the remainder value, and the calculated difference value Is 1 or more Occasionally, the image pattern obtained for the change point coordinate sequence that does not reach the predetermined value is the image pattern after image expansion, and the image pattern in which white pixels or black pixels are continuous according to the obtained difference is An image expansion processing method characterized by outputting as an image pattern. 4. An EOL code indicating a line segment of an image in which code data encoded by a one-dimensional encoding method and code data encoded by a two-dimensional encoding method are mixed, and an addition indicating a code type. The expansion start coordinates and end start coordinates in the image data, which are the targets of image expansion based on the compressed data including the information, are set, and the additional information is detected while detecting the EOL code and the additional information from the compressed data. It is determined whether the code data of the line of interest is based on the one-dimensional coding system or the two-dimensional coding system. From this determination result, if the line of interest is code data based on the one-dimensional coding system, decompression starts. The line corresponding to the code data from the coordinate -1 to the end start coordinate is determined as the target of image decompression, and the white pixel is extracted from the corresponding code data. If the line of interest is the code data by the two-dimensional encoding method from the judgment result, the line corresponding to the code data from the expansion start coordinate to the end start coordinate is image expanded. Of the corresponding code data to generate a change point coordinate sequence from white pixels to black pixels, and the generated change point coordinate information sequence is divided by a predetermined value to obtain a quotient and a remainder value. Then, the difference between the obtained quotient and the quotient obtained for the immediately preceding change point coordinates is obtained. When the obtained difference value is 0, the image pattern for the change point coordinate sequence that does not reach the predetermined value is used as the remainder value. When the value of the calculated difference is 1 or more, the image pattern obtained for the change point coordinate sequence that does not reach the predetermined value is the image pattern after image expansion, and the white Pixel or black An image expansion processing method, wherein an image pattern in which pixels are continuous is output as an image pattern after image expansion.