JP2012160124A - Printing control program, information processing device, printing system, and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency in indexing of an image in generation processing of a print job by a printer driver.SOLUTION: A printer driver includes: a graphic control unit 100 that acquires an image to be output; a number-of-colors determination processing unit 101 that determines the colors of respective pixels constituting the image according to an arrangement order thereof, counts different colors based on the determination result, and causes information for representing the different colors to be stored in an index table 104 in association with index values; an image conversion processing unit 102 that causes the index values associated with the determined colors to be stored in an image buffer 105 according to the arrangement order of the pixels; and a PDL generation processing unit 103 that generates PDL data using the index values stored in the image buffer 105 based on a comparison result of a predetermined upper limit value of the number of the index values and the number of counts of the different colors.

Description

  The present invention relates to a print control program, an information processing apparatus, a printing system, and a printing apparatus, and more particularly to control of the capacity of print data generated by a print control program.

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Such an image processing apparatus is often configured as a multifunction machine that can be used as a printer, a facsimile, a scanner, or a copier by providing an imaging function, an image forming function, a communication function, and the like.

  Among such image processing apparatuses, in a printing apparatus used for outputting an electronic document, a printer that executes print output based on a print job generated in an information processing apparatus such as a PC (Personal Computer) is provided. Generally used. In general, as a software program that realizes a function for generating a print job to be input to a printer, a printer driver corresponding to the function of each printer is installed in the information processing apparatus.

  The printer driver performs processing for reducing the size of the color image data and improving the transfer efficiency of the print job including the color image data to the printer, such as color reduction processing, compression processing, indexing, and thinning processing. Thus, the printing throughput is improved.

  Of the above-described processes, the color reduction process and the thinning process are not adopted from the viewpoint of improving the image quality of the printed image because the color reproducibility of the original image data is impaired. Indexing depends on the number of colors used in the image to be output and does not necessarily reduce the size. The compression processing is used in combination with the above indexing because it is expected to reduce the data capacity to some extent.

  Here, an example of indexing will be described. For example, in an image in which 3 colors of RGB (Red, Green, Blue) are each expressed by 8 bits and 1 pixel is expressed by 24 bits, that is, 3 bytes, an A4 size image of 7015 pixels × 4960 pixels is set as an output target image.

  If the image is included in the print job as it is, it is 3 bytes × 7015 pixels × 4960 pixels and has a capacity of about 104 MB (megabytes). On the other hand, when indexing with an index table of 256 colors (1 byte) having a capacity of 756 bytes, 1 byte × 7015 pixels × 4960 pixels + 756 bytes, the capacity is about 35 MB (megabytes), and can be reduced to about one third of the size. .

  As a technique for reducing the processing amount of print job generation processing by the printer driver, one pixel row in which shading changes among predetermined images such as a gradation image is enlarged to a predetermined width. Thus, a technique for extending one pixel row over the entire rectangular area has been proposed (for example, Patent Document 1). The technique disclosed in Patent Document 1 relates to image compression, and its purpose is different from the present case on the premise of indexing.

  In the indexing process, the number of colors is counted for each image block, and conversion is performed according to a format suitable for the number of colors. For example, when the number of colors falls within 256 colors, it is processed as 8-bit index data. However, when more than 257 colors are used, the original 24-bit format is transmitted even if 257 colors are used. The data amount reduction effect cannot be obtained.

  The present invention has been made in view of the above circumstances, and an object thereof is to improve the efficiency of image indexing processing in print job generation processing by a printer driver.

  In order to solve the above-described problem, one aspect of the present invention provides a print control program for generating print control information for causing a printing apparatus to execute print output, and obtains the image to be printed. Storing in a storage medium; determining a color of each pixel constituting the stored image according to an arrangement order of the pixels; counting a different color based on a determination result of the color of each pixel; Storing information for expressing the different colors in a storage medium in association with an index value, and storing the index value associated with the determined color in a storage medium in accordance with the arrangement order of the pixels; , Based on the result of comparison between the predetermined upper limit value of the number of index values and the count number of the different colors, according to the arrangement order of the pixels. Characterized in that to execute the steps in the information processing apparatus that generates and outputs the print control information with the stored index value each.

  According to another aspect of the present invention, there is provided an information processing apparatus that realizes a print control function for generating print control information for causing a printing apparatus to execute print output, and acquires the image to be printed out. An image acquisition unit, a pixel color determination unit that determines the color of each pixel constituting the acquired image according to the arrangement order of the pixels, and a color count unit that counts different colors based on the determination result of the color of each pixel An index processing unit that stores information for expressing the different colors in the storage medium in association with an index value, and stores the index value associated with the determined color in the storage medium in accordance with the arrangement order of the pixels. An image conversion processing unit to be performed, and a comparison result between a predetermined upper limit value of the number of index values and the number of counts of different colors, and the arrangement order of the pixels Characterized in that it comprises a print control information processing unit for generating and outputting the print control information with the stored index value I.

  According to still another aspect of the present invention, a printing system includes the printing control program and a printing apparatus.

  According to still another aspect of the present invention, a printing apparatus includes a storage unit in which the print control program is stored.

  According to the present invention, it is possible to improve the efficiency of image indexing processing in print job generation processing by a printer driver.

1 is a block diagram showing a functional configuration of a printing system according to an embodiment of the present invention. It is a figure which shows the function structure of the graphics part of the printer driver which concerns on embodiment of this invention. It is a figure which shows the example of 24-bit image data. It is a figure which shows the example of the image data indexed. It is a flowchart which shows operation | movement of the graphic part which concerns on embodiment of this invention. It is a figure which shows the example of the image data produced | generated by the graphic part which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the graphics part which concerns on other embodiment of this invention. It is a figure which shows the hardware constitutions of PC concerning embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, an example of a printing system including a PC (Personal Computer) that is an information processing apparatus in which a printer driver is installed and a printer that is a printing apparatus that executes print output according to a print job generated by the printer driver. Will be described. Note that the printing apparatus does not have to be a printer, but may be any apparatus that executes image formation output based on a print job generated by a printer driver installed in a PC.

  FIG. 1 is a block diagram illustrating a functional configuration of a printing system according to the present embodiment. As shown in FIG. 1, the printing system according to the present embodiment includes a PC 1 and a printer 8, and the PC 1 and the printer 8 are connected via a network 9. In the PC 1, the installed application 2 operates on an OS (Operation System) to provide functions such as document creation and image editing, and is a source of an image to be printed out according to a user operation. Provide information.

  The application 2 activates a UI (User Interface) unit 10a of the printer driver 10 in response to a user operation, and sets print output setting information set via the GUI (Graphical UI) of the UI unit 10a as a DEVMODE structure. Get in the information format called.

  When a print execution command is input by user operation to the UI unit 10a activated by the application 2 or the application 2, the application 2 activates the GDI (Graphics Device Interface) 3 via the UI unit 10a. The DEVMODE structure set in this way and the image information to be output are passed.

  GDI3 is a drawing engine incorporated in an OS that is generally basic software. The GDI 3 activates the graphic unit 10b of the printer driver 10 via DDI (Device Driver Interface), and transfers the processing.

  The graphic unit 10b of the printer driver 10 converts the image data output as an internal command of the OS by the GDI 3 into data in a PDL (Page Description Language) format that is a data format that can be processed by the printer 8 that is to execute print output. Convert. The data in the PDL format is print control information for causing the printer 8 to execute printing. The graphic unit 10b sequentially transfers the data converted into the PDL format to the spooler 4.

  The spooler 4 temporarily stores the data in the PDL format generated by the graphic unit 10 b as a spool file 5 in a storage medium. Thus, even if the printer 8 cannot accept the PDL data after the graphic unit 10b generates the PDL data in the printer driver 10, the printer driver 10 passes the generated PDL data to the spooler 4. Since the next process can be started immediately, the process can be made more efficient.

  The PDL data stored in the storage medium as the spool file 5 is transferred again to the spooler 4 by the printer processor 6 and transmitted to the printer 8 via the network 9 by the port monitor 7.

  Next, the functional configuration of the graphic unit 10b of the printer driver 10 according to the present embodiment will be described with reference to FIG. As shown in FIG. 2, the graphic unit 10b includes a graphic processing unit 100, a color number determination processing unit 101, an image conversion processing unit 102, a PDL generation processing unit 103, an index table 104, and an image buffer 105.

  The graphic control unit 100 controls the entire processing of image data. The color number determination processing unit 101 counts and determines the number of colors of image data, and adds the counted color to the index table. The image conversion processing unit 102 performs conversion processing from image data that is 24-bit data to 4-bit or 8-bit index data, and stores the converted data in an image buffer. The PDL generation processing unit 103 generates data in a PDL (Page Description Language) format based on the converted data stored in the image buffer.

  FIG. 3 is a diagram schematically showing the content of general 24-bit image data. As shown in FIG. 3, in general 24-bit image data, the gradation of each RGB color is 256 gradations such as “R: 0”, “G: 128”, “B: 128”. Pixels expressed by (8 bits) are arranged vertically and horizontally, and the color for one pixel is determined by 256 gradation data of each RGB color. In this case, since the same color is expressed by different data, 24 bits per pixel are always required.

  On the other hand, FIG. 4A is a diagram schematically showing the contents of image data indexed with 256 colors, and FIG. 4B is a diagram showing an example of an index table. As shown in FIG. 4A, in the indexed image data, the color of one pixel is described by an index value such as “0”, “3”, “100”.

  Here, the bit size of the index value shown in FIG. 4A differs depending on the number of colors for indexing. The number of colors for indexing is, for example, 16 colors and 256 colors. If 16 colors are used, 4 bits are used, and if 256 colors are used, 8 bits are used. And as shown in FIG.4 (b), the combination of each RGB color is set corresponding to each index value. Thereby, in the indexed image data, one pixel can be expressed by 8 bits.

  In addition, in the indexed image data, an index table as shown in FIG. 4B is required in addition to image data in which index values as shown in FIG. As shown in FIG. 4B, in the index table, gradation values of RGB, that is, information for expressing the colors of the pixels constituting the image is associated with the index value. The capacity of the 256 color index table is, for example, 756 bytes.

  Next, the operation of the graphic unit 10b according to the present embodiment will be described with reference to the flowchart of FIG. As illustrated in FIG. 5, when the graphic control unit 100 acquires image information input to the graphic unit 10b (S501), the graphic control unit 100 sets current pixels in order from the top pixel. That is, the graphic control unit 100 functions as an image acquisition unit. Then, the color number determination processing unit 101 confirms the color of the current pixel (S502). That is, the color number determination processing unit 101 functions as a pixel color determination unit in S502.

  If the confirmed current pixel color is an unregistered color that has not yet been registered in the index table (S503 / YES), the color number determination processing unit 101 increments the color number counter (S504). That is, the color number determination processing unit 101 functions as a color counter. As a result, when the count value of the color number counter exceeds 256 (S505 / NO), the PDL generation processing unit 103 selects the image of the main scanning line including the current pixel from the image information acquired by the graphic control unit 100. , PDL data is generated as an image of 24-bit data. Then, the graphic control unit 100 outputs the PDL data generated by the PDL generation processing unit 103 to the spooler 4 (S507). When the processing of S507 is executed, the color number determination processing unit 101 clears the index table 104 and the color number counter, and the image conversion processing unit 102 clears the image buffer 105.

  As a result of the processing in S507, PDL data is generated based on an image that remains as 24-bit data for main scanning lines having more than 256 colors. On the other hand, even if the color number counter is incremented, if the count value is within 256 (S505 / YES), the color number determination processing unit 101 registers the color of the current pixel and updates the index table (S506). That is, the color number determination processing unit 101 functions as an index processing unit. The image conversion processing unit 102 adds the index value of the current pixel to the image buffer (S508). It should be noted that the processing of S508 is also executed when the color is a registered color as a result of the confirmation of S503 (S503 / NO).

  When the processing of S508 is completed, the graphic control unit 100 checks whether or not the current current pixel is the end of the line (S509), and if it is not the end of the line (S509 / NO), moves the current pixel (S509 / NO). S514) and the process from S502 are repeated. On the other hand, if it is the line end (S509 / YES), the color number determination processing unit 101 confirms whether the count value of the number of colors is within 16 (S510).

  As a result of the confirmation in S510, if the count value is within 16 (S510 / YES), the PDL generation processing unit 103 has 16 colors (based on the indexed image data and the index table stored in the image buffer 105). PDL data is generated as 4-bit image data, and the graphic control unit 100 outputs the PDL data to the spooler 4 (S511). Since the index table 104 and the image buffer 105 are assumed to have 8 bits, in order to process as 4 bits of data, the upper 4 bits of the 8 bits may be ignored.

  On the other hand, if the count value exceeds 16 (S510 / NO), the PDL generation processing unit 103 is an image of 256 colors (8 bits) based on the indexed image data and the index table stored in the image buffer 105. PDL data is generated as data, and the graphic control unit 100 outputs the PDL data to the spooler 4 (S512). That is, in S511 and S512, the PDL generation processing unit 103 and the graphic control unit 100 function as a print control information processing unit. When the processing of S511 and S512 is executed, the color number determination processing unit 101 clears the index table 104 and the color number counter, and the image conversion processing unit 102 clears the image buffer 105.

  When the processing in any of S507, S511, and S512 is completed, the graphic control unit 100 confirms whether or not the processing has been completed up to the end of the image (S513). As a result of the confirmation, if the processing has not been completed to the end (S513 / NO), the graphic control unit 100 moves the current pixel (S514) and repeats the processing from S502. Here, in the process of S514, the graphic control unit 100 moves from the current current pixel to the adjacent pixel. However, in the case of passing through S507, the graphic control unit 100 moves to the head of the line next to the line including the current current pixel. Moving. If the processing is completed up to the end of the image (S513 / YES), the processing ends.

  As described above, the graphic unit 10b according to the present embodiment generates PDL data for each main scanning line of the output target image and outputs the PDL data to the spooler 4. At this time, the number of colors is counted for each main scanning line, and if it is within 256 colors, PDL data is generated based on 8-bit indexed image data. If it is within 16 colors, PDL data is generated based on 4-bit indexed image data with a smaller amount of information. On the other hand, when the count value exceeds 256 colors, PDL data is generated with the 24-bit data for that line.

  By such processing, as shown in FIG. 6, an image to be printed out is transmitted to the printer 8 as an indexed image for a certain range and as original image data for another range. In the printer 8, the part indexed by the PDL analysis function and the part as the original image data can be similarly recognized as the image data, and the print output can be executed.

  On the other hand, on the PC 1 side, PDL data must be generated based on 24-bit image data for the entire image. However, only the possible portions are indexed, so that the total transmitted to the printer 8 is calculated. Can be reduced, and the transfer efficiency of images can be improved.

  As described above, in the printing system according to the present embodiment, the efficiency of image indexing in the print job generation processing by the printer driver is determined by determining whether or not indexing is possible for each main scanning line. Can do.

  In the above-described embodiment, an example in which indexing is determined for each main scanning line has been described as an example. This is significant because by transmitting an image for each main scanning line, it is not necessary to consider pixel positions on the printer 8 side, and it is only necessary to sequentially stack image data transmitted from the PC 1.

  However, if the number of divisions is increased, so many index tables are required, and the amount of information increases accordingly. Therefore, whether or not indexing is possible may be determined for each of a plurality of lines such as two lines and three lines instead of every line.

  In the image processing in the printer 8, processing may be performed for each unit called “band” obtained by dividing the image in the sub-scanning direction for each predetermined range. Indexing may be determined for each band. In this case, it is necessary to recognize the number of main scanning lines included in one band (hereinafter referred to as a bandwidth) on the PC 1 side. For example, the bandwidth is stored in the graphic control unit 100 as a fixed value for each paper size. This can be realized by letting it go.

  In addition, it is possible to always achieve indexing by generating PDL data by dividing the upper limit of the number of colors of 256 colors, instead of determining whether indexing is possible for each line. Such an aspect is particularly effective in an image including many identical colors, such as an image of a document including many texts. Such an aspect will be described with reference to FIG.

  FIG. 7 is a flowchart showing the operation of the graphic unit 10b when generating PDL data by dividing the upper limit of the number of colors. As shown in FIG. 7, processing from S701 to S705 is executed in the same manner as S501 to S505 in FIG. 5. If the number of colors exceeds 256 as a result of the confirmation in S705 (S705 / NO), the PDL generation processing unit 103 sets 256 based on the indexed image data and the index table stored in the image buffer 105. PDL data is generated as color (8-bit) image data, and the graphic control unit 100 outputs the PDL data to the spooler 4 (S706).

  By the processing in S706, the color number determination processing unit 101 clears the index table 104 and the color number counter, and the image conversion processing unit 102 clears the image buffer 105, as in the case of FIG.

  If the number of colors is 256 or less as a result of the confirmation in S705 (S705 / YES), or when the processing in S706 is completed, the color number determination processing unit 101 updates the index table in the same manner as in S506. (S707) Similar to S508, the image conversion processing unit 102 adds an index value to the image buffer 105 (S708). Note that if the result of the confirmation in S703 is a registered color (S703 / NO), the processing in S708 is also executed.

  The graphic unit 10b repeats such processing from S702 to S708 while moving the current pixel until the end of the image is reached (S709 / NO, S711). When the end of the image is reached (S709 / YES), The PDL generation processing unit 103 generates PDL data as 256-color (8-bit) image data based on the indexed image data and the index table stored in the image buffer 105, and the graphic control unit 100 outputs the PDL data to the spooler 4. (S710), and the process ends.

  As described above, according to the aspect of FIG. 7, since the PDL data is generated and output for each image that can be expressed by the index values of 256 colors, the entire image can be always indexed.

  In the case of the example in FIG. 7, unlike the example in FIG. 5, since the main scanning line of the image is not determined, there is a possibility that the PDL data is output in the middle of the line. Therefore, on the printer 8 side, the image cannot be accurately drawn only by stacking the images included in the received PDL data in the sub-scanning direction. Therefore, when generating the PDL data, the PDL generation processing unit 103 includes information indicating the position in the main scanning direction of the first pixel of the image in the PDL data. Thereby, on the printer 8 side, images separately transmitted from the PC 1 side can be suitably combined based on information indicating the position of the pixel in the main scanning direction.

  The functions shown in FIGS. 5 and 7 are realized by the graphic unit 10b shown in FIG. 2 as described above. The functional configuration of the graphic unit 10b shown in FIG. 2 includes software and hardware. It is realized by the combination. Hereinafter, the hardware configuration of the PC 1 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 8, the PC 1 according to the present embodiment has the same configuration as a general information processing terminal. That is, the PC 1 according to the present embodiment includes a CPU (Central Processing Unit) 30, a RAM (Random Access Memory) 31, a ROM (Read Only Memory) 32, an HDD (Hard Disk Drive) 34, and an I / F 35 via the bus 33. Connected. In addition, an LCD (Liquid Crystal Display) 36 and an operation unit 37 are connected to the I / F 35.

  The CPU 30 is a calculation means and controls the operation of the entire PC 1. The RAM 31 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 30 processes information. The ROM 32 is a read-only nonvolatile storage medium and stores a program such as firmware.

  The HDD 34 is a non-volatile storage medium that can read and write information, and stores an OS (Operating System), various control programs, application programs, and the like. The I / F 35 connects and controls the bus 34 and various hardware and networks. The LCD 36 is a visual user interface for the user to check the state of the PC 1. The operation unit 37 is a user interface such as a keyboard and a mouse for the user to input information to the PC 1.

  In such a hardware configuration, a program stored in a recording medium such as the ROM 32, the HDD 34, or an optical disk (not shown) is read into the RAM 31, and the CPU 30 performs an operation according to these programs, thereby configuring a software control unit. The A functional block for realizing the functions of the PC 1 according to the present embodiment as shown in FIGS. 1 and 2 is configured by a combination of the software control unit configured in this way and hardware.

  The printer driver 10 that realizes the functional configuration of the graphic unit 10b as shown in FIG. 2 is configured by installing a software program stored in an optical storage medium or the like in the HDD 34 of the PC 1, for example. However, the method for installing the printer driver 10 as shown in FIG. 2 is not limited to reading the software program stored in the storage medium to the PC 1, for example, downloading the software program to the PC 1 via the network. This can also be realized.

  In such a case, an installer program for installing the printer driver 10 is stored in a storage medium provided in the printer 8 and the installer program is downloaded from the printer 8 to the PC 1. The driver 10 can be configured. That is, as a distribution form of the printer driver 10 according to the present embodiment, a distribution form as the printer 10 including a storage medium in which the printer driver 10 is stored can be considered.

1 PC
2 Application 3 GDI
4 Spooler 5 Spool file 6 Printer processor 7 Port monitor 8 Printer 9 Network 10 Printer driver 10a UI unit 10b Graphic unit 30 CPU
31 RAM
32 ROM
33 Bus 34 HDD
35 I / F
36 LCD
37 Operation unit 100 Graphic control unit 100
101 Color Number Determination Processing Unit 102 Image Conversion Processing Unit 103 PDL Generation Processing Unit 104 Index Table 105 Image Buffer

JP 2010-152597 A

Claims (10)

A print control program for generating print control information for causing a printing apparatus to execute print output,
Acquiring the image to be printed and storing it in a storage medium;
Determining the color of each pixel constituting the stored image according to the arrangement order of the pixels;
Counting different colors based on the determination result of the color of each pixel;
Storing the information for expressing the different colors in a storage medium in association with an index value;
Storing the index value associated with the determined color in a storage medium according to the order of the pixels;
Based on the comparison result between the predetermined upper limit value of the number of index values and the count number of different colors, the print control information is generated and output using the index values stored in accordance with the arrangement order of the pixels. And a step of causing the information processing apparatus to execute the step.   In the step of generating and outputting the print control information, a comparison result between the upper limit value of the number of index values and the count number of different colors is determined for each predetermined range in the sub-scanning direction of the image. The printing control program according to claim 1, wherein:   In the step of generating and outputting the print control information, if the count number of the different color exceeds the upper limit value of the number of index values, the pixels in the predetermined range including the pixel whose color is being determined And generating and outputting the print control information using the stored original image and the end of the predetermined range in a state where the count number of the different colors is equal to or less than the upper limit value of the number of index values The print control program according to claim 2, wherein when the determination of the color of the pixel is completed, the print control information is generated and output using an index value stored according to the arrangement order of the pixels. In addition to the upper limit value of the number of index values, a threshold value lower than the upper limit value is defined,
In the step of generating and outputting the print control information, the determination of the color of the pixel is completed up to the end of the predetermined range in a state where the count number of the different colors is equal to or less than the upper limit value of the number of index values The print control program according to claim 3, wherein if the count number is equal to or less than the threshold value, the print control information is generated and output using an index value with a reduced number of bits.   5. The print control program according to claim 2, wherein the predetermined range in the sub-scanning direction of the image is every main scanning line.   5. The print control program according to claim 2, wherein the predetermined range of the image in the sub-scanning direction is a range in which the printing apparatus processes the print control information.   In the step of generating and outputting the print control information, the print control information is generated using an already stored index value every time the number of different color counts exceeds the upper limit of the number of index values. The print control program according to claim 1, wherein the print control program is output in the same manner. An information processing apparatus for realizing a print control function for generating print control information for causing a printing apparatus to execute print output,
An image acquisition unit for acquiring an image to be printed;
A pixel color determination unit that determines the color of each pixel constituting the acquired image according to the arrangement order of the pixels;
A color counting unit that counts different colors based on the determination result of the color of each pixel;
An index processing unit that stores information for expressing the different colors in a storage medium in association with an index value;
An image conversion processing unit that stores the index value associated with the determined color in a storage medium according to the arrangement order of the pixels;
Based on the comparison result between the predetermined upper limit value of the number of index values and the count number of different colors, the print control information is generated and output using the index values stored in accordance with the pixel arrangement order. An information processing apparatus including a print control information processing unit.   A printing system comprising the printing control program according to claim 1 and a printing apparatus.   A printing apparatus comprising: a storage unit in which the print control program according to claim 1 is stored.

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