JP4720872B2 - Image processing apparatus and program - Google Patents

Description

  The present invention relates to an image processing apparatus and a program.

  In an image processing apparatus such as a printer, a copier, or a multifunction peripheral (an apparatus having the functions of a printer, a scanner, and a copier), an image having a larger area than the sheet of the apparatus is divided into a plurality of sheets. Some of them have the function of printing out paper separately. This type of apparatus, for example, prints A1 size images by dividing them into four A3 sizes or printing them by dividing them into eight A4 sizes. Hereinafter, such a printing process is referred to as divided printing.

  Patent Document 1 discloses, for example, divided printing in which an image is divided into preset paper size units, such as two A3 size sheets for an A2 size image and four A3 size sheets for an A1 size image. An image processing apparatus having a function is disclosed. It is also disclosed that when an output paper size is designated by a client computer, the image processing apparatus divides and outputs an image in the designated paper size unit. In any case, the image processing apparatus generates a raster image by interpreting the input page description language data, and divides the raster image into a preset paper size or a paper size designated by the user, Each divided raster image is printed on paper.

  Once split printing has been performed with a certain paper size setting, and then split printing is performed again after changing the paper size to be used, the conventional technology reinterprets the page description language data and regenerates the raster image. The raster image is divided for each paper size to be used.

  On the other hand, in order to reduce the data transfer amount in the image data transfer path such as between the image memory and the print engine, or to reduce the amount of image data to be temporarily stored, a function to compress the raster image once generated is provided. The provided image processing apparatus is also widespread. In this type of image processing apparatus, when divided printing is performed many times by changing the size of the paper to be used, the raster image is regenerated, divided, and each image of a small area after compression is compressed each time printing is performed. A series of processes will be repeated.

  If the raster image itself before division is stored in the image processing apparatus, it is not necessary to regenerate the raster image, but the storage capacity of the image processing apparatus is used in large quantities. In this method, the compression processing of each image after division is still necessary.

  It is also conceivable that a compressed image of a raster image before division is saved, and when the division printing is instructed again, the compressed image is expanded to reproduce the original raster image and divided into paper size units. . However, this method requires processing for decompressing the compressed image. Further, the compression processing of each image after division is still necessary.

  In addition, there is an image processing apparatus having a function of cutting out and printing a part of an original image (so-called trimming function). When printing multiple times while changing the portion to be cut out with this type of device, each time the original image is generated by interpreting the page description language data or expanding the compressed image, the partial image is cut out from the original image and compressed Processing will be performed.

JP 2003-046762 A

  The present invention provides a method that does not require data compression of a partial image for a cutout range after the change even when the cutout range from the original image data is changed.

The invention according to claim 1 compresses original image data for each block of a predetermined size, and compresses each compressed block, which is a compression result of each block, in an array corresponding to the block array in the original image data. Compression means for generating original image data; storage means for storing the compressed original image data; accepting means for receiving input of partial specifying information for specifying a positional range of a partial image to be cut out from the original image data; By recognizing each compressed block in the compressed original image data according to the arrangement, the range of the compressed block group in the compressed original image data corresponding to the positional range of the partial image specified by the partial specifying information is determined. identified, with cut out compressed block group belonging to the specified range from the previous SL compressed original image data, image width and height of the partial image And clipping means for outputting data including said compressed blocks cut out the header information indicating the number units as compressed data of the partial image, and decompressing the compressed data of the partial image in which the cut-out means has outputted, and outputs extended And an output unit.

  According to a second aspect of the present invention, in the first aspect of the invention, the compression unit includes: a block code of the original image data; a boundary code indicating a boundary of the block in the compressed original image data; and compression of the block And converting the data block into a compressed block including the data code as a result, and the clipping unit identifies each compressed block by detecting a boundary code of each compressed block from the compressed original image data, and the identification result is obtained. A range of the compressed block group corresponding to the positional range of the partial image to be cut out is obtained based on.

According to a third aspect of the present invention, in the first aspect of the invention, the accepting unit accepts designation relating to an image size of a division unit when the original image data is divided and output as the partial specifying information, and the clipping unit includes: , Specifying the positional range of each partial image as a result of the division of the original image data based on the image size of the division unit represented by the partial specifying information, and the range corresponding to the specified positional range of each partial image cutting the compressed blocks from the previous SL compressed original image data, characterized in that.

In the invention according to claim 4, the computer compresses the original image data for each block of a predetermined size, and each compressed block as a compression result of each block is an array corresponding to the block array in the original image data. Compression means for generating aligned compressed original image data, storage means for storing the compressed original image data, accepting means for receiving input of partial specifying information for specifying a positional range of a partial image to be cut out from the original image data, By recognizing each compressed block in the compressed original image data according to the arrangement, the range of the compressed block group in the compressed original image data corresponding to the positional range of the partial image specified by the partial specifying information is determined. identified, with cut out compressed block group belonging to the specified range from the previous SL compressed original image data, the width及of the partial image Clipping means for outputting a data including the height said compressed blocks cut out the header information shown by each number of pixels as compressed data of the partial image, and decompressing the compressed data of the partial image in which the cut-out means has outputted, It is a program for functioning as decompression output means for outputting.

  According to the first or fourth aspect of the invention, even when the positional range cut out from the original image data is changed, compressed data in the changed range is obtained, and re-compression is unnecessary.

  According to the second aspect of the present invention, it is possible to specify the range on the compressed original image data corresponding to the positional range to be extracted by searching for the boundary code.

  According to the third aspect of the invention, the original image data can be divided into a plurality of partial images and output.

  A method of image division processing in this embodiment will be described with reference to FIG. For example, a case where the maximum paper size is A3 and the A1 size original image data 10 is divided into four A3 size images and printed is taken as an example.

  In the prior art, after dividing the original image data 10 into, for example, four A3 sizes, images of the division results (called divided images) are image-compressed and temporarily stored, and then decompressed and printed.

  On the other hand, in this embodiment, the original image data 10 is image-compressed, and the compressed original image data 12 that is the compression result is divided into four compressed partial image data 14a, 14b, 14c, and 14d. Then, the compressed partial image data 14a, 14b, 14c, and 14d are expanded and printed, respectively, to obtain A3 size four-division print results 16a, 16b, 16c, and 16d.

  In this way, in order to divide the image at the level of the compressed image data, in this embodiment, an image compression method is used in which the position on the compressed image data corresponding to the position on the original image data can be specified.

  There are several image compression methods that satisfy these requirements. Here, a code that divides the original image into blocks of a predetermined size and compresses them in units of blocks, and indicates the boundaries of the blocks for each block. A compression method for generating compressed data including As such a compression method, for example, the following can be used.

  In this method, a block of pixel data constituting an original image to be printed is generated for each k pixels (k is an integer of 2 or more) continuous in the main scanning direction, and the data of these pixels is compressed in units of blocks. For example, when one pixel has a data width of 1 byte, line data in the main scanning direction of the original image is divided into M (M is a natural number) k-byte fixed-length blocks and compressed for each block. What is used as a compression algorithm for compressing a block is not essential for the image division method in this embodiment, but for example, the same as that disclosed in Japanese Patent Application Laid-Open No. 2007-88685, It is possible to use a predictive coding method in which coding is performed using matching (or error) of an image between a block of interest and a reference block in the vicinity (for example, immediately before or immediately above). An example of the data structure of the compression result obtained by this kind of compression algorithm is shown in FIG.

  As illustrated in FIG. 2, a page code 100 that is a compression result of an image of one page includes a header code 110 and M line codes 120-1 to 120 -M that are compression results for each line in the main scanning direction. (Hereinafter collectively referred to as line code 120). That is, in this example, one page includes M lines. The header code 110 includes information indicating the special characteristics of the page, such as the width and height (for example, the number of pixels) of the page.

  Each line code 120 includes a marker code 130 and N block codes 140-1 to 140-N (hereinafter, collectively referred to as a block code 140) which are compression results for each block.

  The marker code 130 is a code indicating information on the entire line, and includes an identifier code 150 and a data code 160. The identifier code 150 is a predetermined code that represents the head of the line. The data code 160 includes information indicating the characteristics of the compressed data of the line, such as the code amount of the line. Note that the line unit marker code 130 is a code introduced in order to make it easy to distinguish lines, assuming an editing operation of compressed data (for example, rotating an image 180 degrees with compressed data). It is not essential for decryption. Since the header information 110 includes page size (width and height) information, even if there is no marker code 130, the decoded pixel data is folded for each page width and arranged in raster scan order. This is because the page can be reconstructed.

  The block code 140 includes an identifier code 170 and a data code 180. The identifier code 170 is a code including information indicating which reference block in the vicinity of the block the data code 180 as a compression result is based on, for example. For example, when the block matches the reference block, the data code 180 has, for example, a value obtained by encoding the number of times of matching (run length). With the encoded value.

  For the identifier codes 150 and 170, code words that are not used for the data codes 160 and 180 are used, and code words corresponding to the identifier codes 150 and 170 other than the positions of the identifier codes 150 and 170 do not appear. . Thus, by searching for the identifier codes 150 and 170 from the compressed image data, it becomes possible to specify the head of each line or the head of each block. Thereby, the compressed image data can be divided or cut out in units of blocks.

  When the image to be printed is a color image, for example, the above-described compression can be performed for each color image of cyan, magenta, yellow, and black.

  Next, an example of a functional configuration of the image processing apparatus according to this embodiment will be described with reference to FIG. In this example, the image processing apparatus includes an image input unit 20, an image compression unit 22, a storage device 24, an instruction reception unit 26, a control unit 28, a cutout unit 30, an image expansion unit 32, and a printing unit 34.

  The image input unit 20 is a part for inputting an original image to be printed. The image input unit 20 is an interpreter that generates raster image data by processing print data described in a page description language, for example. The image input unit 20 may be a scanner that optically reads a paper document and generates raster image data.

  The image compression unit 22 can specify the position on the compressed image data corresponding to the position on the original image data, as exemplified above, on the original image (raster image) data input from the image input unit 20. Compress with a simple image compression method. Compressed image data as a result of this compression is stored in a storage device 24 such as a hard disk. The compressed image data stored in the storage device 24 is read out by the control unit 28 and used for printing.

  The instruction receiving unit 26 is, for example, a user interface mechanism that receives an instruction from the user for the image processing apparatus. In relation to this embodiment, the instruction receiving unit 26 receives a split output instruction for original image data, a trimming instruction for cutting out and outputting a part of the original image data, and the like. In addition, divided output and trimming instructions may be described in print data in a page description language.

  The control unit 28 controls the printing process of the image processing apparatus. In relation to this embodiment, the control unit 28 causes the cutout unit 30 to cut out the compressed image data in accordance with the split output instruction or the trimming instruction. The cutout unit 30 performs a process of cutting out a portion instructed from the control unit 28 from the compressed image data.

  The image decompression unit 32 decompresses the compressed image data by the decompression method corresponding to the compression method of the image compression unit 22 and reproduces the raster image data. The reproduced raster image data is printed on the paper by the printing unit 34.

  An example of a processing procedure of the control unit 28 when receiving an instruction for dividing and outputting original image data will be described with reference to FIG.

  The division output instruction includes, for example, size specifying information that is a basis for obtaining the size of the division unit. The size specifying information includes, for example, the paper size in units of division, or the number of divisions indicating how many times the original image is divided. The divided output instruction for the compressed original image data stored in the storage device 24 includes information for specifying the compressed original image data to be divided and output.

  Upon receiving such a division output instruction, the control unit 28 calculates, based on the size specifying information, the positional range (in other words, the position of the boundary of each division image) occupied by each division image as the division result in the original image data. (S10). This positional range is described in units of pixels, for example.

  For example, the original image data is A1 size (the number of pixels in the horizontal (x) direction is P, the number of pixels (lines) in the vertical (y) direction is Q), and A3 is specified as the size of the division unit. Taking the case as an example: That is, in this case, the original image data is divided into four divided images, and the positional range of the first divided image is such that the left end is x = 1, the right end is x = P / 2, the upper end is y = 1, and the lower end. Is a range surrounded by four sides of y = Q / 2. Similarly, the positional range of the second divided image is x = (P / 2) +1 to P, y = 1 to (Q / 2), and the positional range of the third divided image is x = 1 to (P / 2), y = (Q / 2) +1 to Q, and the positional range of the fourth divided image is x = (P / 2) +1 to P, y = (Q / 2) +1 to Q.

  Next, the control unit 28 converts the positional range of each of the divided images into block units (S12). Assuming that one block is one vertical line × horizontal k pixels, for example, in the first divided image, the left end is x = 1, the right end is x = (P / 2) / k, and the upper end is y. = 1, and the lower end is in the range y = (Q / 2). Similarly, for the second to fourth divided images, a range in units of blocks is obtained.

  Next, the control unit 28 instructs the cutout unit 30 to cut out a portion corresponding to each divided image from the compressed original image data (S14). This cutout instruction includes information on the cutout range (that is, the range of the divided image) expressed in block units for each divided image.

  After this instruction, the control unit 28 waits for the compressed image data of each divided image to be delivered from the cutout unit 30 (S16). When the compressed image data of each divided image is received, the compressed image data is decompressed. The data is transferred to the section 32 and expanded, and the expanded result is printed on the printing section 34 (S18).

  Next, an example of the processing procedure of the cutout unit 30 will be described with reference to FIG. In this example, it is assumed that the compressed original image data to be divided has the data structure illustrated in FIG.

  In this procedure, first, the header code 110 at the head of the compressed original image data (that is, the page code 100) is skipped (S20), and the marker code 130 is searched to set the cut start line (that is, the upper line of the cut range). Find (S22). That is, for example, the cutout unit 30 searches the code word pattern corresponding to the identifier code 150 in the marker code 130 while sequentially reading the compressed original image data, and counts up the line number counter each time the identifier code 150 is found. To go. The line number counter indicates the number (y coordinate) of the line (referred to as the current line) being processed by the cutout unit 30. The search in step S22 may be terminated when the value of the line number counter reaches the line number of the cut start line. At the end of the search, the clipping unit 30 looks at the top of the clipping start line on the compressed original image data.

  Even if the compressed original image data does not have the marker code 130 representing the head of the line, the number of blocks per line is already known, so by detecting and counting the identifier code 150 of the block code 140, the current The line number of the line can be determined.

  Next, the cutout unit 30 finds a cutout start block (that is, a block corresponding to the left end of the cutout range) by searching the block identifier code 170 in order from the top of the cutout start line (S24). That is, for example, the cutout unit 30 searches the code word pattern corresponding to the identifier code 170 in the block code 140 while sequentially reading the compressed image data of the line, and counts the block number counter every time the identifier code 170 is found. I will go up. The block number counter is cleared every time the processing of the cutout unit 30 reaches the head of the line. Therefore, the block number counter indicates the number (x coordinate) of the block processed by the cutout unit 30 (referred to as the current block) when viewed from the line head. The search in step S24 may be terminated when the value of the block number counter reaches the number of the cut start block. At the end of the search, the cutout unit 30 sees the cutout start block on the cutout start line on the compressed original image data.

  Next, the cutout unit 30 sequentially reads each block code of the current line, and cuts out each block code 140 from the current block (cutout start block) to the cutout end block (that is, the block corresponding to the right end of the cutout range) (S26). ). The block code 140 group cut out from the current line is added to the cut-out image area secured on the memory (not shown) of the image processing apparatus.

  Prior to this addition, a header code 210 (see FIG. 6) representing the compressed image of the cutout result is created and stored in the cutout image area, for example, by the control unit 28. The header code 210 includes information that represents the size (width and height) of the image as a cutout result in units of pixels. This information can be obtained from the size of the original image data and the divided output instruction. The block code 140 group cut out in step S26 is added after the header code 210.

  Next, the cutout unit 30 determines whether or not the current line indicated by the line number counter has reached the cutout end line (that is, the lower end line of the cutout range) (S28). If the current line has not reached the cut-out end line, for example, the next marker code 130 is searched while scanning the compressed original image data sequentially from the current block, and the next line is moved (S30). Then, by performing the processes of steps S24 to S28 on the line, the block code 140 group within the cutout range on the line is cut out and added to the cutout image area.

  By repeating the processes of steps S24 to S30 described above from the cutout start line to the cutout end line, compressed image data of the cutout range is formed in the cutout image area on the memory. The cutout unit 30 passes the compressed image data in the cutout image area to the control unit 28 as a cutout result (S32).

  FIG. 6 shows an example of the data structure of the compressed image data formed in the cut-out image area. In this example, the cut out compressed image data (page code 200) includes a header code 210 and line codes 220-1, 220-2,..., 220-m of each line (hereinafter referred to as line code 220. m is a generic name). The number of cut lines). The line code 220 includes block codes 240-1, 240-2,..., 240-n (n is the number of cutout blocks per line), but does not include the marker code 130. Even if the marker code 130 is not provided, the pixel data of the decoding result can be arranged for each line by referring to the information on the number of pixels per line included in the header information, so that decoding is possible.

  In the case of divided output, the cutout unit 30 may perform the cutout process exemplified above for each cutout range (divided image). Instead of this, a cutout image area corresponding to each of the four cutout ranges is secured in the memory, and the block code 140 belonging to each cutout range is handled while the compressed original image data is scanned from the beginning to the end. May be added to the cut-out image area. According to such processing, four divided images are generated in parallel while the compressed original image data is scanned once.

  As described above, in this embodiment, the division of the compressed original image data is performed by searching for and counting the identifier codes 170 (and 150). Such processing requires much less computational cost than decoding the compressed original image data. As described above, in this embodiment, the compressed original image data is divided as it is without being decoded.

  As described above, the image processing apparatus according to this embodiment generates compressed image data of each divided image by dividing the compressed original image data. Therefore, it is not necessary to compress the divided image. For example, even when dividing output is performed after changing the division method (for example, the paper size of the division unit), the compressed original image data only needs to be re-divided in this embodiment. There is no need to recompress.

  Note that the method of this embodiment can be applied not only to divided output of an image but also to trimming output. An example of the processing procedure of the control unit 28 in the case of trimming output is shown in FIG.

  The trimming output instruction includes, for example, designation of a positional range (cutout range) to be trimmed. The cutout range is represented by, for example, a set of the upper and lower y coordinates of the cutout range in the original image data and the left and right end x coordinates (each coordinate is a pixel unit).

  When receiving the trimming instruction including the designation of the cutout range, the control unit 28 converts the cutout range into blocks (S40). The conversion method may be the same as in the case of divided output. Note that since the compressed image data is cut out in units of blocks, the cutout range on the original image data is also specified in units of block sizes.

  Next, the control unit 28 instructs the cutout unit 30 to cut out a portion corresponding to the cutout range from the compressed original image data (S42). This cutout instruction includes information on the cutout range expressed in blocks.

  After this instruction, the control unit 28 waits for the compressed image data in the cutout range to be delivered from the cutout unit 30 (S44). When the compressed image data is received, the control unit 28 passes the compressed image data to the image decompression unit 32. The decompression result is printed on the printing unit 34 (S46).

  According to this embodiment, even when trimming output is performed again after changing the cutout range, the cutout range may be cut out from the compressed original image data, and the cutout image data need not be compressed again.

  In the above embodiment, the block size is 1 vertical pixel × horizontal k pixel. However, as is clear from the above-described configuration and processing procedure example, the same is true even when the vertical size of the block is a plurality of pixels. Processing is possible.

  Further, the compression method of the image compression unit 22 is not limited to the above-described example, and compression is performed in units of blocks, and the data format of the compressed image data is the boundary between adjacent blocks (the head or the end of the block may be used). ) May be any data format that can be detected.

  The arithmetic processing part of the image processing apparatus described above is realized, for example, by causing a general-purpose computer to execute a program representing the processing of each functional module described above. Here, for example, as shown in FIG. 8, the computer includes, as hardware, a microprocessor such as a CPU 300, a memory (primary storage) such as a random access memory (RAM) 302 and a read-only memory (ROM) 304, an HDD ( An HDD controller 308 that controls a hard disk drive) 306, various I / O (input / output) interfaces 310, a network interface 312 that performs control for connection to a network such as a local area network, and the like are connected via a bus 314, for example. Circuit configuration. In addition, the bus 314 has various standards such as a disk drive 316 for reading from and / or writing to a portable disk recording medium such as a CD and a DVD and a flash memory via a I / O interface 310, for example. A memory reader / writer 318 for reading from and / or writing to the nonvolatile recording medium may be connected. A program in which the processing contents of each functional module illustrated above are described is stored in a fixed storage device such as a hard disk drive via a recording medium such as a CD or DVD, or via communication means such as a network, and stored in a computer. Installed. The program stored in the fixed storage device is read into the RAM 302 and executed by a microprocessor such as the CPU 300, whereby the functional module group exemplified above is realized. Some or all of these functional module groups are used as hardware circuits such as dedicated LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field Programmable Gate Array). It may be configured.

It is a figure for demonstrating the division | segmentation output process of the image in embodiment. It is a figure which shows an example of the data structure of the compression data by the compression system used by embodiment. It is a figure which shows the example of a function structure of the image processing apparatus of embodiment. It is a flowchart which shows the example of the process sequence of the control part at the time of receiving a division | segmentation output instruction | indication. It is a figure which shows the example of the process sequence of a cutout part. It is a figure which shows the example of the structure of the compression data of the partial image which the cutout part produced | generated. It is a flowchart which shows the example of the process sequence of the control part at the time of receiving a trimming instruction | indication. It is a figure which shows an example of the hardware constitutions of a computer.

Explanation of symbols

  20 image input unit, 22 image compression unit, 24 storage device, 26 instruction reception unit, 28 control unit, 30 clipping unit, 32 image decompression unit, 34 printing unit.

Claims (4)

Compression means for compressing original image data for each block of a predetermined size and generating compressed original image data in which each compression block as a compression result of each block is arranged in an array corresponding to the block array in the original image data When,
Storage means for storing the compressed original image data;
Receiving means for receiving input of partial specifying information for specifying a positional range of a partial image to be cut out from the original image data;
By recognizing each compressed block in the compressed original image data according to the arrangement, the range of the compressed block group in the compressed original image data corresponding to the positional range of the partial image specified by the partial specifying information identify, with cut out compressed block group belonging to the specified range from the previous SL compressed original image data, and a said compression blocks cut out the header information indicating the width and height of the partial image in the pixel unit number data Cutting out means for outputting as compressed data of the partial image ,
Decompression output means for decompressing and outputting the compressed data of the partial image output by the clipping means;
An image processing apparatus comprising: The compression means converts each block of the original image data into a compression block including a boundary code indicating a boundary of the block in the compressed original image data and a data code which is a compression result of the block,
The clipping means identifies each compressed block by detecting a boundary code of each compressed block from the compressed original image data, and a compressed block group corresponding to the positional range of the partial image to be clipped based on the identification result Find the range of
The image processing apparatus according to claim 1. The accepting means accepts designation relating to an image size of a division unit when the original image data is divided and output as the part specifying information;
The cutout unit specifies a positional range of each partial image, which is a division result of the original image data, based on the image size of the division unit represented by the partial specifying information, and sets the positional range of each specified partial image. cutting the compressed blocks corresponding range of pre-Symbol compressed original image data,
The image processing apparatus according to claim 1. Computer
Compression means for compressing original image data for each block of a predetermined size and generating compressed original image data in which each compression block as a compression result of each block is arranged in an array corresponding to the block array in the original image data ,
Storage means for storing the compressed original image data;
Receiving means for receiving input of partial specifying information for specifying a positional range of a partial image to be cut out from the original image data;
By recognizing each compressed block in the compressed original image data according to the arrangement, the range of the compressed block group in the compressed original image data corresponding to the positional range of the partial image specified by the partial specifying information identify, with cut out compressed block group belonging to the specified range from the previous SL compressed original image data, and a said compression blocks cut out the header information indicating the width and height of the partial image in the pixel unit number data Cutting out means for outputting as compressed data of the partial image ,
Decompression output means for decompressing and outputting the compressed data of the partial image output by the clipping means;
Program to function as.