JP2006013624A - Image output system, control apparatus, image output method, image output program, and storage medium stored with the program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of a tone jump even when a dot image with a comparatively low resolution is outputted. <P>SOLUTION: The image output system, which is provided with dot reference data wherein threshold value data are arranged in a way of growing dots to have a shape including directivity, generates dots on the basis of the dot reference data in each range of raster image data, and greatly grows the shape of the dots earlier in a first direction than a second direction in crossing with the first direction in a dot growth process by each density of the image in the dot generation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for performing the above-described halftoning processing in a control device that performs halftoning processing on image data received from an external device and transmits the processed halftone processing to an image output device having a relatively low resolution. .

  In recent years, with the spread of DTP (Desk Top Publishing) and the like, print orderers use their own terminals to edit images input from scanners on computer software and perform page imposition. Editing is no longer unusual.

  In such a printing plate making process, aiming for further efficiency, image setter output for directly outputting the image data with the page imposition to the film, CTP (Computer to Plate) output for directly recording the image on the printing plate, Further, CTC (Computer to Cylinder) is performed in which image recording is performed directly on a printing plate wound on a cylinder of a printing press.

  In this case, once film output or printing plate output is performed only for calibration confirmation, and printing calibration or calibration with other calibration materials causes waste in the film or printing plate, and there are many extra work. There is a problem.

  Therefore, in the process of creating and editing a full digital image by such a computer, a system for directly outputting a color image called DDCP (Direct Digital Color Proof) has been demanded.

  For example, such DDCP records image data with page imposition on a plate-making film with an image setter or the like, or performs a printing operation to directly create a printing plate with a plate setter (hereinafter referred to as CTP), Before performing direct image recording on a printing plate wound on a cylinder of a printing machine with CTC, a DCP (Digital Color Proof) that is a color sample that reproduces this is created and its design, color tone, etc. Used for calibration.

  Furthermore, before creating a DCP using such a DDCP, a small-size output of single page image data (image data before page imposition) is performed by a general-purpose printer such as a color laser printer, and the output It is performed to calibrate the design, color tone, text, etc. of the color comp that is an object.

  As described above, in the printing plate making process, it is common to create and calibrate a color comp or DCP for proofreading a picture, tone, or text to be output by DDCP before performing a printing operation. It is the target.

  Recently, with the improvement in performance of color laser printers, it has become possible to produce high-quality color output at low cost and at high speed. Therefore, this color laser printer should be used for DCP creation. Has been tried.

  Examples of the color laser printer include an electrophotographic color laser printer disclosed in Japanese Patent Application Laid-Open No. 5-48857, and a multifunction machine having a scanner / copier / facsimile function (for example, Patent Document 1). reference).

  By the way, CTP which is the final image output machine described above performs halftone screen by a binary screen system of ON (1) or OFF (0). That is, the gradation (shading) is expressed by the size of the halftone dot area. One of the reasons is that the output resolution of CTP is very high (generally 2400 [dpi] or more).

  Generally, the number of screen lines (an index indicating how many halftone dots can exist per 1 inch) used in commercial printing is 150 [lpi] or more, but an output of 2400 [dpi] In the case of a printer having a resolution, in the case of 150 [lpi], one halftone dot can be formed by 16 × 16 (2400/150) minimum pixels, so the gradation is 256 gradations. It has sufficient gradation.

  However, in the case where the gradation is expressed by the size of the area of the halftone dots, it is necessary to pay attention to the tone jump, and so far, for example, the gradation reproduction method described in JP 2000-326562 A As described above, various devices in the process of growing halftone dots have been proposed (see, for example, Patent Document 2). This is mainly devised in the way of joining with surrounding halftone dots. This is because a tone jump is likely to occur at a location where the halftone dots are in contact with each other.

Japanese Patent Laid-Open No. 5-48857 (paragraphs [0011]-[0070], FIGS. 1 to 2) JP 2000-326562 A (paragraphs [0023]-[0069], FIGS. 1 to 8)

  Incidentally, as described above, when the color laser printer is used for the purpose of creating the DCP, it is preferable to perform the same processing as the image processing performed on the CTP. That is, it is preferable to express the gradation of the image data with halftone dots.

  However, the output resolution of such a color laser printer is generally low, and many are about 600 [dpi] to 1200 [dpi]. Here, for example, when trying to obtain a screen line number of 150 [lpi] at 600 [dpi], one halftone dot is formed by 4 × 4 pixel groups, and the number of gradations thereof Is at most 16 gradations (this is not a sufficient gradation).

  For this reason, more recent color laser printers are capable of performing a so-called multi-value halftoning process in which one pixel is drawn at a multi-value level according to the image density. Here, for example, if one pixel can be expressed at 16 levels, even a halftone dot composed of 4 × 4 pixel groups can express 16 gradations × 16 gradations = 256 gradations. Therefore, sufficient gradation can be obtained.

  However, when a halftone image is output using such a relatively low-resolution color laser printer, the number of pixels constituting one halftone dot is small, and therefore a portion joined to the surrounding halftone dots. Becomes relatively large. Here, as shown in FIGS. 2 and 3 of the above-mentioned Japanese Patent Laid-Open No. 2000-326562, the halftone dot (= the halftone dot relative to the total number of pixels of the pixel group arranged to form one halftone dot) The halftone dot having a square shape that grows to a size that is in contact with other adjacent halftone dots when the ratio of the number of pixels constituting the pixel) is around 50% Will occur at the same time, causing a problem that tone jumping becomes severe.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an image output apparatus capable of performing multi-value halftoning processing with relatively low resolution. When it is used for image output, each halftone dot constituting the halftone dot image is formed in a shape having directivity such as a rhombus or an ellipse, so that each halftone dot is joined to the surrounding halftone dots. An object of the present invention is to provide a technique capable of suppressing occurrence of a tone jump by dispersing the occurrence locations according to the density of an image.

  In order to solve the above-mentioned problems, the invention described in claim 1 is an image output system that generates halftone dot image data for each color plate from image data and outputs a halftone dot image based on the halftone dot image data. When the image data is not subjected to RIP processing, raster image generating means for performing RIP processing on each image data to generate raster image data for each color plate, and predetermined threshold data in a matrix form And halftone dot reference data storage means for storing halftone dot reference data for each color plate, and the pixels constituting the pixel group by associating the halftone dot reference data with the pixel groups in each range of the raster image data The halftone dot data and the threshold value data of the halftone dot reference data are compared, and one halftone dot is generated by defining the presence / absence of the output of each pixel. From the raster image data for each color plate, Halftone image data A halftone dot processing means for generating data, and an image output means for outputting a halftone image based on the halftone dot image data for each color plate. In the case where the pixel group is defined as a highlight portion, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot is generated only in the first direction.

  According to a second aspect of the present invention, there is provided an image output system for generating halftone dot image data for each color plate from image data and outputting a halftone dot image based on the halftone dot image data. When RIP processing is not performed, raster image generation means for generating Raster image data for each color plate by applying RIP processing to each image data, and a color plate in which predetermined threshold data is arranged in a matrix Halftone dot reference data storage means for storing another halftone dot reference data, the halftone dot reference data corresponding to the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group; Comparing with threshold value data of halftone dot reference data, one halftone dot is generated by defining the output of each pixel, and halftone dot image data for each color plate is generated from raster image data for each color plate Dot halftone And halftone image processing means for outputting a halftone image based on the halftone dot image data for each color plate, and the halftone processing means includes a portion in which the density value data highlights the pixel group. If the density value data defines the image group as a shadow part, generating a halftone dot that extends in the direction of joining with the surrounding halftone dots only in the first direction, A halftone dot having a shape extending in a direction joining with a surrounding halftone dot in the first direction and a second direction intersecting with the first direction is generated.

  According to a fourth aspect of the present invention, there is provided an image output system for generating halftone dot image data for each color plate from image data and outputting a halftone dot image based on the halftone dot image data. When RIP processing is not performed, raster image generation means for generating Raster image data for each color plate by applying RIP processing to each image data, and a color plate in which predetermined threshold data is arranged in a matrix Halftone dot reference data storage means for storing another halftone dot reference data, the halftone dot reference data corresponding to the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group; Comparing with threshold value data of halftone dot reference data, one halftone dot is generated by defining the output of each pixel, and halftone dot image data for each color plate is generated from raster image data for each color plate Dot halftone Image output means for outputting a halftone image based on the halftone dot image data for each color plate, and the halftone dot reference data has a predetermined value according to the halftone dot to be generated. The threshold value data is arranged in an array in which the shape of a halftone dot is grown in the first extension direction before the second extension direction that intersects the first extension direction.

  The invention described in claim 7 is an image output control device that generates halftone dot image data for each color plate from image data and causes the image forming apparatus to output an image based on the halftone dot image data. When the image data is not subjected to RIP processing, raster image generating means for performing RIP processing on each image data to generate raster image data for each color plate, and predetermined threshold data in a matrix form And halftone dot reference data storage means for storing halftone dot reference data for each color plate, and the pixels constituting the pixel group by associating the halftone dot reference data with the pixel groups in each range of the raster image data The halftone dot data and the threshold value data of the halftone dot reference data are compared, and one halftone dot is generated by defining the presence / absence of the output of each pixel. From the raster image data for each color plate, Halftone image data And a transmission unit for adding output control information to the halftone image data and transmitting it to the image forming apparatus. The halftone processing unit includes the density value data. In the case where the pixel group is defined as a highlight portion, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot is generated only in the first direction.

  The invention according to claim 8 is an image output control device that generates halftone dot image data for each color plate from image data and causes the image forming apparatus to output an image based on the halftone dot image data. When the image data is not subjected to RIP processing, raster image generating means for performing RIP processing on each image data to generate raster image data for each color plate, and predetermined threshold data in a matrix form And halftone dot reference data storage means for storing halftone dot reference data for each color plate, and the pixels constituting the pixel group by associating the halftone dot reference data with the pixel groups in each range of the raster image data The halftone dot data and the threshold value data of the halftone dot reference data are compared, and one halftone dot is generated by defining the presence / absence of the output of each pixel. From the raster image data for each color plate, Halftone image data And a transmission unit for adding output control information to the halftone image data and transmitting it to the image forming apparatus. The halftone processing unit includes the density value data. When the pixel group is defined as a highlight portion, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated, and the density value data sets the image group as a shadow portion. In the first direction and the second direction intersecting with the first direction, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot is generated.

  The invention according to claim 10 is an image output control device for generating halftone dot image data for each color plate from image data and outputting a halftone dot image based on the halftone dot image data, wherein the image data In the case where the RIP processing is not performed, the raster image generating means for performing the RIP processing on each of the image data to generate raster image data for each color plate, and a color in which predetermined threshold data is arranged in a matrix Halftone dot reference data storage means for storing halftone dot reference data for each plate; and density value data of pixels constituting the pixel group, the halftone dot reference data corresponding to the pixel groups in each range of the raster image data; The halftone dot reference data is compared with the threshold value data, and one halftone dot is generated by defining the presence or absence of the output of each pixel, and the halftone dot image data for each color plate is obtained from the raster image data for each color plate. Halftone dot to be generated Processing means, and image output means for outputting a halftone image based on the halftone dot image data for each color plate, and the halftone dot reference data has a predetermined value according to the halftone of the halftone dot to be generated. The threshold value data is arranged in an array in which the shape of a halftone dot is grown in the first extension direction before the second extension direction that intersects the first extension direction.

  The invention according to claim 13 is an image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone image data, The dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored in advance, and when each image data is not subjected to RIP processing, each image data is subjected to RIP processing. Raster image data for each color plate is generated, the halftone dot reference data is associated with the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group and the halftone dot reference data Comparing with threshold data, based on the comparison result, one dot is generated by specifying the output of each pixel, and dot image data for each color plate is generated from raster image data for each color plate The halftone dot generation described above When the density data defines the pixel group as a highlight portion, in the generation of the halftone dot, a halftone dot having a shape that extends in a direction joined to the surrounding halftone dot only in the first direction is generated. A halftone dot image is output based on the halftone dot image data for each color plate.

  The invention according to claim 14 is an image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone image data, The dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored in advance, and when each image data is not subjected to RIP processing, each image data is subjected to RIP processing. Raster image data for each color plate is generated, the halftone dot reference data is associated with the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group and the halftone dot reference data Comparing with threshold data, based on the comparison result, one dot is generated by specifying the output of each pixel, and dot image data for each color plate is generated from raster image data for each color plate The halftone dot generation described above When the density data defines the pixel group as a highlight portion, in the generation of the halftone dot, a halftone dot having a shape that extends in a direction joined to the surrounding halftone dot only in the first direction is generated. When the density value data defines the image group as a shadow portion, a halftone dot having a shape extending in the direction joining the surrounding halftone dots in the first direction and the second direction intersecting with the first direction is generated. And a halftone dot image is output based on the halftone dot image data for each color plate.

  The invention according to claim 16 is an image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone image data, The dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored in advance, and when each image data is not subjected to RIP processing, each image data is subjected to RIP processing. Raster image data for each color plate is generated, the halftone dot reference data is associated with the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group and the halftone dot reference data Comparing with threshold data, based on the comparison result, one dot is generated by specifying the output of each pixel, and dot image data for each color plate is generated from raster image data for each color plate Halftone image data for each color plate The halftone dot image is output based on the halftone dot reference data, and the halftone dot reference data includes the second dot extension direction that intersects the predetermined first extension direction according to the dot percentage of the halftone dot to be generated. The threshold value data is arranged in an array for growing the shape of halftone dots in one extension direction.

  According to a nineteenth aspect of the present invention, there is provided an image output program for causing an image output control device configured by a computer to execute processing for generating halftone dot image data for each color plate from image data. If the output control device executes processing for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix in advance, and the image data is not subjected to RIP processing, RIP processing is performed on each image data to generate raster image data for each color plate, and the halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data to form the pixel groups The pixel density value data is compared with the threshold value data of the halftone dot reference data, and one halftone dot is generated by defining the presence or absence of the output of each pixel. The processing for generating halftone dot image data for each color plate is executed, the output control information is added to the halftone dot image data, and the processing for transmission to an image forming apparatus is executed. When at least a highlight portion is defined, the generation of the halftone dots is performed by generating a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction. And

  The invention according to claim 20 is an image output program for causing an image output control device configured by a computer to execute processing for generating halftone dot image data for each color plate from image data, the image output program comprising: If the output control device executes processing for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix in advance, and the image data is not subjected to RIP processing, RIP processing is performed on each image data to generate raster image data for each color plate, and the halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data to form the pixel groups The pixel density value data is compared with the threshold value data of the halftone dot reference data, and one halftone dot is generated by defining the presence or absence of the output of each pixel. The processing for generating halftone dot image data for each color plate is executed, the output control information is added to the halftone dot image data, and the processing for transmission to an image forming apparatus is executed. In the case where at least the highlight portion is defined, in the generation of the halftone dots, a process of generating halftone dots having a shape extending in a direction joining with the surrounding halftone dots only in the first direction is executed, and the density value When the data defines the image group as a shadow portion, processing for generating a halftone dot having a shape extending in a direction joining the surrounding halftone dot in the first direction and the second direction intersecting the first direction. It is further characterized by being executed.

  According to a twenty-second aspect of the present invention, there is provided an image output program for causing an image output control device configured by a computer to execute processing for generating halftone dot image data for each color plate from image data. When the output control device executes processing for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in advance in a matrix, and when the image data is not subjected to RIP processing, Pixels constituting the pixel group by executing RIP processing on the image data to generate raster image data for each color plate, making the halftone dot reference data correspond to the pixel groups in each range of the raster image data By comparing the density value data of the image and the threshold value data of the halftone dot reference data, one halftone dot is generated by defining the presence or absence of output of each pixel, and raster image data for each color plate The halftone dot image data for each color plane is generated, and the halftone dot reference data includes a second extension that intersects a predetermined first extension direction according to the halftone dot percentage of the halftone dot to be generated. The threshold value data is arranged in an array in which the shape of a halftone dot is grown in the first extension direction before the direction.

  According to a twenty-fifth aspect of the invention, there is provided a storage medium in which the image output program according to any of the nineteenth to twenty-fourth aspects is stored so as to be readable by the image output control device.

  According to the image output system, the control device, the image output method, the image output program, and the storage medium storing the program according to the present invention, the threshold data is arranged so that the halftone dots grow in a shape having directivity. A process for generating a halftone dot based on the halftone dot reference data is performed, and the shape of the halftone dot is output because the first direction grows larger than the second direction intersecting the first direction. In the halftone image, the occurrence locations where individual halftone dots join with surrounding halftone dots are dispersed according to the density of the image, and tone jumps can be suppressed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of an image forming system, a control device, an image output method, an image output program, and a storage medium storing the program according to the invention will be specifically described with reference to the drawings.

  The system configuration of the image output system in the present embodiment will be described in detail with reference to FIG.

  As shown in FIG. 1, the image output system includes at least one client terminal 1, a control device 2 and a color laser printer 3 for outputting comp image data, CTP CIP RIP4 and CTP6, The DCP control device 5 for DCP and the DCP creation device 7 are connected to each other via a network.

  The client terminal 1 performs image editing of image data, for example, imposition work. Then, after editing the image, the client terminal 1 transmits the image data described in PostScript to the control device 2 as comp image data that is single-page image data before page imposition, and print image data To the CTP RIP4. The transmitted image data includes non-photographic image objects such as characters and graphics, and the non-photographic image objects exist as vector data in the image data.

  The CTP RIP 4 performs RIP processing when print image data in which a plurality of comp image data are imprinted is transmitted from the client terminal 1. RIP processing interprets image data described in PostScript, and converts the image data into raster image data that matches the output resolution of an image forming apparatus such as CTP6, DCP creation apparatus 7 or color laser printer 3, that is, This is a conversion to bitmap data, which is a collection, so-called rasterization. Here, when the color laser printer 3 is used for DCP or CTP, the print image data may be subjected to RIP processing in accordance with the output resolution of the color laser printer 3, or the RIP processing is left to the control device 2, so Only vectorization of fonts and page imposition processing for CTP output may be performed.

  The control device 2 analyzes the comp image data transmitted from the client terminal 1 via the network and the print image data transmitted from the CTP RIP 4, and performs RIP processing if it is not raster image data. Further, halftone dot conversion processing is performed for converting raster image data into image data composed of halftone dots in accordance with the output resolution of the color laser printer 3, that is, halftone dot image data. Then, an output instruction of halftone image data, information for designating the size and output direction of the recording paper for outputting the halftone image, and the like are transmitted to the color laser printer 3 together with the halftone image data as output control information.

  The color laser printer 3 is a multi-function printer including an electrophotographic copying unit and a scanning unit such as an image scanner, and stores recording sheets of different sizes in different output directions (vertical and horizontal). A plurality of paper feed cassettes and storage means for storing the size and output direction of the recording paper stored in each of the paper feed cassettes are provided. The color laser printer 3 feeds the recording paper of the corresponding size and output direction from the corresponding paper feed cassette according to the output control information transmitted from the control device 2, and based on the comp image data on the recording paper. Print images based on comp images and print image data are output.

  The CTP 6 outputs a printing image based on the printing image data transmitted from the CTP RIP 4, the DCP control device 5 performs output control of the DCP creation device 7, and the DCP creation device 7 controls the DCP control device 5. A printing image based on the printing image data transmitted via the network is output.

  The client terminal 1, the control device 2, the CTP RIP 4 and the DCP control device 5 each operate as a computer terminal. The computer terminal, operation means such as a mouse and keyboard, display means such as a monitor, etc. In particular, the control device 2 executes each process of the present embodiment by an image output program stored in the ROM or HDD. Furthermore, the client terminal 1 includes necessary image input devices such as an editing program for image editing and an image scanner.

Next, the schematic operation of the image output system will be described along the flow of the flowchart shown in FIG. 2 while following the flow of the printing plate making process.

  As shown in FIG. 2, the image data edited by the client terminal 1 is transmitted to the control device 2, and the control device 2 having received the analysis analyzes the image data and is not yet raster image data. Then, RIP processing is performed to convert it into raster image data. Further, the raster image data is subjected to halftone dot processing to be converted into halftone dot image data, and the halftone dot image data is transmitted to the color laser printer 3 together with output control information.

  The color laser printer 3 that has received the halftone dot image data and the output control information outputs the halftone dot image based on the halftone dot image data to the recording paper of the corresponding size and output direction, thereby outputting the comp image. A comp is created (S01).

  The “color comp” mentioned here is a colored finish sample, and the design conforms to the intention of planning and editing by showing a finished image close to the printed material as a dummy of the photo and illustration to be imprinted on the page. It is created for the purpose of examining whether it is a product or obtaining the consent of the client. That is, at this time, a small-sized comp image is output on a single page, and the print orderer or designer confirms the work results such as character calibration and color calibration (S02).

  Here, when it is confirmed that there is a problem by the print orderer or the designer (S02, No), image editing or the like is performed again at the client terminal 1, and a color comp is created by the color laser printer 3. The Here, when it is confirmed that there is no problem (S02, Yes), the imposition work is performed on the client terminal 1 by the operator of the printing company as the client (S03). The “impositioning” here refers to a noble (a number placed at the end of a page so that the page number can be seen when the plate-making film is printed and made into a signature. This is an operation of pasting images such as photographs and illustrations in units of 16 pages, 8 pages or 4 pages according to the size of the paper to be applied to the printing press.

  When the printing company data is transmitted from the client terminal 1 to the CTP RIP 4 by the operator of the printing company, the received CTP RIP 4 receives the print image data. Then, RIP processing is performed in accordance with the output resolution of the DCP creation device 7 or CTP6. (S04).

  When DCP is created by the color laser printer 3 or when the color laser printer 3 is used for CTP, the CTP RIP 4 performs only vectorization and imposition of character fonts on the print image data. The RIP process may be left to the control device 2 or the RIP process may be performed. Receiving this, the control device 2 analyzes the image data for printing, and if it is not yet raster image data, it performs RIP processing and further performs halftone processing (S05).

  The halftone image data is transmitted to the color laser printer 3 together with output control information by the control device 2. In response to this, the color laser printer 3 outputs the halftone dot image based on the halftone dot image data to the recording paper of the corresponding size and output direction according to the output control information, so that the DCP on which the printing image is output is output. Create (S06).

  Here, when high-precision DCP is required, the RIP 4 for CTP transmits raster image data to the DCP control device 5, and the DCP control device 5 that receives this transmits the output control of the DCP creation device 7. The DCP creating device 7 creates an image based on the print image data, thereby creating a DCP.

  Then, color calibration of the created DCP is performed by a print orderer or a designer. Here, when it is confirmed that there is a problem (S07, No), after various setting information (in addition to color adjustment, output direction, output size, etc.) is changed in the control device 2, it is again performed. The color laser printer 3 outputs an image based on the printing image data to a recording sheet, thereby creating a DCP.

  If it is confirmed that there is no problem in the created DCP (S07, Yes), the print orderer or the designer sends the print image data, which is raster image data, from the CTP RIP 4 to the CTP 6. Then, the CTP 6 receiving this directly records an image on the printing plate (S08). Further, the operator of the printing company performs printing using the printing plate, and performs color calibration of the impositioned image that is the printed material. If it is confirmed that there is no problem (S09, Yes), the process proceeds to the step of printing the printed material by the printing machine (S10).

  Next, the halftone processing and border processing of comp image data and print image data performed in the control device 2 will be described in detail with reference to FIGS. In the following, the image output system will be described by taking as an example the case of creating a DCP using the color laser printer 3.

  As shown in FIG. 3, the control device 2 performs RIP processing on the print image data transmitted from the CTP RIP 4 to generate raster image data, and performs halftone processing on the raster image data to generate a halftone image. This is a device that generates data, adds output control information, and transmits the data to the color laser printer 3.

  That is, the control device 2 includes an image data storage unit 20 that stores print image data. Further, the image data analysis processing unit 21 that performs RIP processing is provided, and includes a halftone dot reference data storage unit 22 and a halftone dot conversion unit 23 that perform halftone processing, and transmission that transmits halftone image data to the color laser printer 3. Part 26 is provided. The image data storage unit 20 is configured by the RAM of the control device 2, the halftone dot reference data storage unit 22 is configured by an HDD, and the other units are controlled by the CPU based on an image output program stored in the ROM or the HDD. Consists of operations. It should be noted that each of these parts does not preclude being configured by a dedicated circuit.

The image data storage unit 20 stores the print image data received from the CTP RIP 4. The image data for printing has been subjected to imposition processing and is described in PostScript or the like. The print image data includes raster image data generated by CIP RIP4 RIP processing and generated in four colors of CMYK and special colors such as gold and silver (hereinafter also referred to as “special colors”) 1 and 2. However, a vector format in which the character font of the image data for printing is vectorized and imposition processing may be used.
The raster image data is bitmap data composed of pixels that match the output resolution of the color laser printer 3. Each pixel constituting the raster image data is assigned predetermined density value data corresponding to the density of the pixel. FIG. 4A shows a pixel group existing in an arbitrary range of rasterized printing image data, and shows a pixel group in a highlight portion and a pixel group in a shadow portion. As the density value data, for example, numerical values of 0 to 255 of 256 gradations are applied as shown in FIG. In the present embodiment, raster image data for each color plate that has been subjected to RIP processing in the RIP 4 for CTP is stored.

  The image data analysis processing unit 21 analyzes the print image data. If the RIP process is not performed by the CTP RIP 4, the description contents of the print image data are sequentially read, sequentially subjected to the RIP process, and finally processed. Raster image data is generated from printing image data.

  The dot reference data storage unit 22 stores dot reference data for each color plate in advance. The halftone dot reference data is used when a printing image is formed with halftone dots. As shown in FIG. 4B, the halftone dot reference data is composed of a threshold matrix in which a plurality of threshold data is arranged in a matrix. The threshold value matrix is prepared for each output intensity according to the number of output intensity variable stages set in the color laser printer 3. That is, the halftone dot reference data storage unit 22 is halftone dot reference data storage means for storing halftone dot reference data in which predetermined threshold data is arranged in a matrix.

  In the halftone dot reference data, each threshold value data is arranged on each threshold matrix based on the halftone dot shape, the halftone dot arrangement angle, the number of lines, and the halftone dot density. In the present embodiment, as shown in FIG. 4B, the threshold matrix of each output intensity is a 4 × 4 matrix, and the number of output intensity variable stages of the color laser printer 3 is set to 5 stages, and each output intensity is divided into four stages. There are threshold matrices.

  In such halftone dot reference data, in particular, the arrangement of each threshold data considering the shape of the halftone dot is the first extension direction in the predetermined first extension direction of the halftone dot according to the halftone percentage. This is an arrangement in which the shape of the halftone dot is grown prior to the second extending direction orthogonal to each other. The halftone percentage is a ratio of pixels that are defined as having an output in order to generate a halftone dot in a predetermined range of pixels that form one halftone dot.

  FIG. 4B shows halftone dot reference data in a predetermined color plate, and the halftone dot array angle is 45 degrees. This halftone dot reference data is set with the first diagonal direction being the same as the halftone dot arrangement angle in the threshold matrix. That is, the halftone dot reference data is arranged in such a manner that threshold data with a low threshold value is preferentially arranged in the first direction in each threshold matrix. Next, the next threshold data having a lower threshold value is arranged so as to gradually cover the threshold data arranged in a diagonal line. In other words, the connection direction connecting the threshold data with the lowest threshold value in each row and each column of the threshold value matrix becomes the first direction, and from each threshold data on the connection in each row direction and each column direction. The threshold value data is arranged so that the threshold value increases as the distance increases.

  According to the halftone dot reference data of the present embodiment, as the halftone dot increases from 0% to 100%, the halftone dot first expands with the first direction as the first extension direction and the first direction as the first direction. When the extension reaches the maximum as the extension direction, halftone dot image data is generated in which the next extension direction is the second extension direction and the halftone dots have a directional shape. That is, as shown in FIG. 4 (C), the halftone dot reference data causes the halftone dot to be in a predetermined first extension direction of the halftone dot from a second extension direction orthogonal to the first extension direction. Halftone dot image data having a shape that grows first is generated. For example, the halftone dot image data includes an elliptical or rhombic halftone dot. Such halftone dot reference data has the directivity in the shape of the halftone dots, thereby dispersing the joint occurrence points in the highlight portion and the shadow portion.

  In the halftone dot reference data for each color plate, threshold data having a low threshold value may be preferentially arranged in correspondence with the halftone dot arrangement angle for each color plate. Of course, a direction different from the halftone dot arrangement angle can be set as the first direction, and the second direction may be a direction that intersects the first direction. Each threshold value data of the halftone dot reference data is arranged so that the growth in the first direction reaches the maximum at the halftone dot where the halftone percentage is approximately 50%.

  The halftone dot conversion unit 23 applies the above-described halftone dot reference data to the raster image data for each color plate in accordance with the RIP process sequentially performed by the image data analysis processing unit 21 to form the halftone dots sequentially. Another halftone image data is generated.

  In the generation of halftone dots, each threshold value matrix of halftone dot reference data is first assigned to a predetermined range of pixels to correspond to each other. By this fitting, the density value data of each pixel of the pixel group and the corresponding threshold data are compared for each threshold matrix. As a result of the comparison, if there are a plurality of threshold matrices in which there is threshold data with density value data exceeding, the threshold data belonging to the threshold matrix of the maximum output intensity among the plurality is adopted. Then, output data based on the output intensity of the threshold matrix to which the adopted threshold data belongs is allocated to the pixel to which the density value data is arranged. As a result, as shown in FIG. 4C, output data from “0” defining no output to “1 to 4” defining output is allocated to each pixel and output to each pixel. Strength is defined. One halftone dot is formed by “1 to 4” of the pixel group, and the density of the halftone dot itself is defined.

  As shown in FIG. 4C, the halftone dot image data is generated from the raster image data. That is, for the pixel group in each range of the raster image data, the halftoning unit 23 compares the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data corresponding to the pixel group. Then, by defining whether or not each pixel is output, one halftone dot is generated, and halftone dot processing means for generating halftone dot image data from the raster image data is obtained.

  FIG. 4C shows halftone dot image data formed based on the halftone dot reference data in this embodiment. The highlighted pixel group and the shadow pixel group in FIG. This is halftone image data corresponding to the highlight portion and the shadow portion generated by being compared with the reference data. In the present embodiment, the halftone dot conversion unit 23 uses the halftone dot reference data as described above to form a halftone dot forming a highlight portion where the halftone percentage is a relatively low portion, as shown in FIG. The point is generated as a directional shape extended in the first direction rather than the second direction. When the halftone dot percentage becomes relatively high, the halftone dot forming section 23 gradually expands and expands halftone dots that form the shadow part, which is the part where the halftone percentage becomes high percentage. It is generated as a going shape.

  In each of the above-described configurations, the description contents of the printing image data are sequentially read in synchronization with a clock generation unit (not shown), and the above-described operations are repeated until the description contents of the printing image data reach the end. The printing image data is subjected to RIP processing in parallel and becomes raster image data, and the raster image data is subjected to halftone processing to become halftone image data. Ultimately, each process is performed on all print image data for each color plate of CMYK and special colors 1 and 2.

  The generated halftone dot image data for each color plate is based on the above-described halftone dot reference data, and when a predetermined pixel group of raster image data is defined as a highlight portion by density value data, Only in one direction, halftone dots having a shape to be joined to the surrounding halftone dots are generated to form halftone dot image data. In the case of being defined in the shadow portion, halftone dots having a shape to be joined to the surrounding halftone dots in the second direction in addition to the first direction are generated as halftone image data.

  The transmission unit 26 adds output control information to the halftone dot image data for each color plate that has been halftoned by the halftoning unit 23, and transmits both to the color laser printer 3. That is, the transmission unit 26 serves as a transmission unit that adds output control information to the halftone image data and transmits it to the image forming apparatus.

  Next, operations of the control device 2 and the color laser printer 3 of the image output system according to the present embodiment will be described in detail with reference to FIGS.

  When print image data is transmitted from the CTP RIP 4, the print image data is stored in the image data storage unit 20 (S11). When the image output program is activated, the image data analysis processing unit 21 first analyzes whether the print image data is raster image data. If the image data is not raster image data, the description content of the print image data is determined. Are sequentially read to generate raster image data for each color plate (S12). Through this process, the printing image data becomes raster image data in which predetermined density value data among all 256 gradations is attached to each pixel according to the output resolution of the color laser printer 3.

  The image analysis processing unit 21 passes the description content of the printing image data that has become raster image data to the halftone dot conversion unit 23, and the halftone dot conversion unit 23 performs a halftone dot conversion process on the received raster image data ( S13).

  In the present embodiment, as shown in FIG. 4A, the raster image data passed to the halftone dot conversion unit 23 is a pixel to which 40, which is density value data in which the density value data defines a highlight portion, is added. The group data and the density value data are pixel group data to which 232, which is density value data defining a shadow portion, are added. As shown in FIG. 4B, the halftone dot reference data is composed of four output intensity threshold matrices that define five levels of output intensity and form a maximum of 4 × 4 halftone dots. .

  The halftone dot conversion unit 23 first reads the halftone dot reference data shown in FIG. 4B from the halftone dot reference data storage unit 22. The halftone dot conversion unit 23 that has read the halftone dot reference data applies each threshold value matrix of the halftone dot reference data to the pixel group shown in FIG. 4A, compares each threshold value data with the density value data, and sets the density value data. The threshold data belonging to the threshold matrix of the maximum output intensity is adopted among the threshold data exceeding. Then, output data based on the output intensity of the threshold matrix to which the adopted threshold data belongs is attached to each pixel. As a result, as shown in FIG. 4C, each pixel of the pixel group is assigned “0” that specifies no output and “1 to 4” that specifies output, and one halftone dot is displayed. Generated. Further, the density of the halftone dot is represented by the output data of 1 to 4, and multi-value halftone dot image data is generated.

  At this time, as shown in FIG. 4C, based on the raster image data having the density value data defining the highlight portion, the halftone dot shape that has been first extended with the first direction as the first extension direction is obtained. Halftone dot image data is generated, and based on raster image data having density value data defining a shadow portion, in addition to the first direction, a halftone dot shape expanded with the second direction as the second extension direction Representing halftone image data is generated.

  By repeating S11 to S13, multi-value halftone dot image data is sequentially generated from the read data, and finally generation of multi-value halftone dot image data for each color plate is completed from the printing image data. As shown in FIG. 4C, the multi-value halftone dot image data has a halftone dot shape that joins with the surrounding halftone dots only in the first direction, that is, the halftone dot arrangement direction, in the highlighted portion. In the portion, a halftone dot shape joined to the surrounding halftone dots in the second direction, that is, a direction orthogonal to the halftone dot arrangement direction.

  The halftone dot image data for each color plane is transferred to the transmission unit 26. The transmission unit 26 adds the output control information to the received halftone dot image data for each color plate and transmits it to the color laser printer 3 (S14). Then, in the color laser printer 3, a halftone image based on halftone dot image data for each color plate consisting of basic colors is output on the recording paper with sufficient gradation. In addition, depending on the present embodiment, the generation point where each halftone dot is joined to the surrounding halftone dot is dispersed according to the image density, and at the same time, the halftone dot joining the surrounding halftone dot is formed during the growth process. Therefore, the occurrence of tone jump can be suppressed.

  As a result, the color laser printer 3 capable of performing multi-value halftoning processing with a relatively low resolution of about 120 [dpi] is used for the purpose of outputting a halftone image. However, by configuring each halftone dot constituting the halftone dot image in a shape having directivity such as a rhombus or an ellipse, the output halftone dot image has a relatively low resolution, Sufficient gradation can be obtained, and occurrence points where individual halftone dots join with surrounding halftone dots are dispersed to suppress occurrence of tone jump.

  Incidentally, the image output program may be stored in a storage medium readable by the control device 2, and specific examples of the storage medium include a semiconductor memory such as a ROM, a RAM, a flash memory, and a memory such as an integrated circuit. Apparatus, optical disk, magneto-optical disk (CD-ROM / DVD-RAM / DVD-ROM / MO, etc.), magnetic storage medium <magnetic disk> (hard disk / floppy (registered trademark) disk / ZIP, etc.), etc. .

  The image output system in the present embodiment described above exemplifies a preferred embodiment of the present invention, and does not exclude other embodiments. For example, in this embodiment, when outputting halftone dots as an image output apparatus capable of performing multi-value halftone processing (= multi-tone halftone image output) with relatively low resolution. The color laser printer 3 that changes the exposure amount of the image has been described as an example. However, other than this, for example, an ink jet recording apparatus described in Japanese Patent Application Laid-Open No. 2004-082710 and Japanese Patent Application Laid-Open No. 2001-260331 is used. In addition, an ink that expresses one pixel in multiple gradations by using a photo ink with a low color material density in addition to the normal C, M, Y, K ink, or changing the ink discharge amount. A printer or the like may be used.

It is a block diagram showing the whole structure in one Embodiment of the image output system which concerns on this invention. FIG. 2 is a flowchart for explaining a series of flows of printing plate making work performed in the image output system shown in FIG. 1. FIG. It is a functional block diagram showing the detailed structure of the control apparatus shown in FIG. It is explanatory drawing about halftone dot conversion among the image output processes in a control apparatus, (A) is a figure which shows the pixel group of the predetermined range of the rasterized image data for printing, (B) is this figure FIG. 6C is halftone dot reference data according to the embodiment, and FIG. 6C is a diagram illustrating halftone dot image data in which the pixel group of FIG. FIG. 4 is a flowchart for explaining a flow of image output processing in the control device shown in FIG. 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Client terminal 2 Control apparatus 20 Image data storage part 21 Image data analysis process part 22 Halftone dot reference | standard data storage part 23 Halftone dot part 24 Transmission part 3 Color laser printer

Claims (25)

An image output system for generating halftone dot image data for each color plate from image data and outputting a halftone image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Image output means for outputting a halftone image based on the halftone image data for each color plate;
With
The halftone dot processing means includes:
When the density value data defines the pixel group as a highlight portion, generating halftone dots having a shape extending in a direction joining with surrounding halftone dots only in the first direction;
An image output system characterized by An image output system for generating halftone dot image data for each color plate from image data and outputting a halftone image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Image output means for outputting a halftone image based on the halftone image data for each color plate;
With
The halftone dot processing means includes:
When the density value data defines the pixel group as a highlight portion, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated,
When the density value data defines the image group as a shadow portion, a halftone dot having a shape extending in the direction joining the surrounding halftone dots in the first direction and the second direction intersecting with the first direction is generated. To do,
An image output system characterized by The first direction in the shape of the halftone dot is elongated longer than the second direction;
The image output system according to claim 2. An image output system for generating halftone dot image data for each color plate from image data and outputting a halftone image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Image output means for outputting a halftone image based on the halftone image data for each color plate;
With
The dot reference data includes
The threshold value data is an array in which the shape of the halftone dot is grown in the first extension direction before the second extension direction intersecting the predetermined first extension direction according to the halftone dot% to be generated. Being arranged,
An image output system characterized by The dot reference data includes
The threshold data is arranged in the first direction in the order of the low threshold, and the threshold data arranged in the first direction is further arranged so as to cover the remaining threshold data in the order of the low threshold.
The image output system according to claim 4. The dot reference data includes
The threshold data is arranged in an arrangement in which the growth in the first direction reaches a maximum when the mesh% is approximately 50%;
The image output system according to claim 4. An image output control device that generates halftone dot image data for each color plate from image data and causes an image forming apparatus to output an image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Transmission means for adding output control information to the halftone image data and transmitting it to the image forming apparatus;
With
The halftone dot processing means includes:
When the density value data defines the pixel group as a highlight portion, generating halftone dots having a shape extending in a direction joining with surrounding halftone dots only in the first direction;
An image output control device characterized by the above. An image output control device that generates halftone dot image data for each color plate from image data and causes an image forming apparatus to output an image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Transmission means for adding output control information to the halftone image data and transmitting it to the image forming apparatus;
With
The halftone dot processing means includes:
When the density value data defines the pixel group as a highlight portion, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated,
When the density value data defines the image group as a shadow portion, a halftone dot having a shape extending in the direction joining the surrounding halftone dots in the first direction and the second direction intersecting with the first direction is generated. To do,
An image output control device characterized by the above. The first direction in the shape of the halftone dot is elongated longer than the second direction;
The image output control device according to claim 8. An image output control device for generating halftone dot image data for each color plate from image data and outputting a halftone image based on the halftone dot image data,
Raster image generation means for performing RIP processing on each image data to generate raster image data for each color plate when the image data is not subjected to RIP processing;
Halftone dot reference data storage means for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix;
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel A halftone dot processing means for generating one halftone dot by defining the presence or absence of color, and generating halftone dot image data for each color plate from raster image data for each color plate;
Image output means for outputting a halftone image based on the halftone image data for each color plate;
With
The dot reference data includes
The threshold value data is an array in which the shape of the halftone dot is grown in the first extension direction before the second extension direction intersecting the predetermined first extension direction according to the halftone dot% to be generated. Being arranged,
An image output control device characterized by the above. The dot reference data includes
The threshold data is arranged in the first direction in the order of the low threshold, and the threshold data arranged in the first direction is further arranged so as to cover the remaining threshold data in the order of the low threshold.
The image output control apparatus according to claim 10. The dot reference data includes
The threshold data is arranged in an arrangement in which the growth in the first direction reaches a maximum when the mesh% is approximately 50%;
The image output control apparatus according to claim 10. An image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone dot image data,
In advance, dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored,
If each image data is not subjected to RIP processing, RIP processing is performed on each image data to generate raster image data for each color plate,
Corresponding the halftone dot reference data to the pixel groups in each range of the raster image data, comparing the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data,
Based on the comparison result, one halftone dot is generated by defining the output of each pixel, and halftone dot image data for each color plate is generated from the raster image data for each color plate,
The generation of the halftone dots described above is
When the density value data defines the pixel group as a highlight portion, in the generation of the halftone dot, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated. ,
Outputting a halftone image based on the halftone image data for each color plate;
An image output method characterized by the above. An image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone dot image data,
In advance, dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored,
If each image data is not subjected to RIP processing, RIP processing is performed on each image data to generate raster image data for each color plate,
Corresponding the halftone dot reference data to the pixel groups in each range of the raster image data, comparing the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data,
Based on the comparison result, one halftone dot is generated by defining the output of each pixel, and halftone dot image data for each color plate is generated from the raster image data for each color plate,
The generation of the halftone dots described above is
When the density value data defines the pixel group as a highlight portion, in the generation of the halftone dot, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated. ,
When the density value data defines the image group as a shadow portion, a halftone dot having a shape extending in the direction joining the surrounding halftone dots in the first direction and the second direction intersecting with the first direction is generated. And
Outputting a halftone image based on the halftone image data for each color plate;
An image output method characterized by the above. The first direction in the shape of the halftone dot is elongated longer than the second direction;
The image output method according to claim 14. An image output method for generating halftone dot image data for each color plate from image data for each color plate, and outputting a halftone image based on the halftone dot image data,
In advance, dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is stored,
If each image data is not subjected to RIP processing, RIP processing is performed on each image data to generate raster image data for each color plate,
Corresponding the halftone dot reference data to the pixel groups in each range of the raster image data, comparing the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data,
Based on the comparison result, one halftone dot is generated by defining the output of each pixel, and halftone dot image data for each color plate is generated from the raster image data for each color plate,
Based on the halftone dot image data for each color plate, a halftone dot image is output,
The dot reference data includes
The threshold value data is an array in which the shape of the halftone dot is grown in the first extension direction before the second extension direction intersecting the predetermined first extension direction according to the halftone dot% to be generated. Being arranged,
An image output method characterized by the above. The dot reference data includes
The threshold data is arranged in the first direction in the order of the low threshold, and the threshold data arranged in the first direction is further arranged so as to cover the remaining threshold data in the order of the low threshold.
The image output method according to claim 16. The dot reference data includes
The threshold data is arranged in an arrangement in which the growth in the first direction reaches a maximum when the mesh% is approximately 50%;
The image output method according to claim 16. An image output program for causing an image output control apparatus configured by a computer to execute processing for generating halftone dot image data for each color plate from image data,
In the image output control device,
In advance, a process of storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is executed,
If the image data is not subjected to RIP processing, the image data is subjected to RIP processing to generate raster image data for each color plate,
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel By creating a halftone dot by specifying the presence or absence of the color, and executing a process of generating halftone dot image data for each color plate from raster image data for each color plate,
A process of adding output control information to the halftone image data and transmitting it to the image forming apparatus is executed.
When the density value data defines the pixel group as at least a highlight portion, in the generation of the halftone dot, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated. To execute the process to
An image output program characterized by An image output program for causing an image output control apparatus configured by a computer to execute processing for generating halftone dot image data for each color plate from image data,
In the image output control device,
In advance, a process of storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in a matrix is executed,
If the image data is not subjected to RIP processing, the image data is subjected to RIP processing to generate raster image data for each color plate,
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel By creating a halftone dot by specifying the presence or absence of the color, and executing a process of generating halftone dot image data for each color plate from raster image data for each color plate,
A process of adding output control information to the halftone image data and transmitting it to the image forming apparatus is executed.
When the density value data defines the pixel group as at least a highlight portion, in the generation of the halftone dot, a halftone dot having a shape extending in a direction joining with a surrounding halftone dot only in the first direction is generated. Execute the process to
When the density value data defines the image group as a shadow portion, a halftone dot having a shape extending in the direction joining the surrounding halftone dots in the first direction and the second direction intersecting with the first direction is generated. To execute further processing,
An image output program characterized by The first direction in the shape of the halftone dot is elongated longer than the second direction;
21. An image output program according to claim 20, wherein: An image output program for causing an image output control apparatus configured by a computer to execute processing for generating halftone dot image data for each color plate from image data,
In the image output control device,
A process for storing halftone dot reference data for each color plate in which predetermined threshold data is arranged in advance in a matrix is executed,
If the image data is not subjected to RIP processing, the image data is subjected to RIP processing to generate raster image data for each color plate,
The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, the density value data of the pixels constituting the pixel group and the threshold value data of the halftone dot reference data are compared, and the output of each pixel By creating a halftone dot by specifying the presence or absence of the color, and executing a process of generating halftone dot image data for each color plate from raster image data for each color plate,
The dot reference data includes
The threshold value data is an array in which the shape of the halftone dot is grown in the first extension direction before the second extension direction intersecting the predetermined first extension direction according to the halftone dot% to be generated. Being arranged,
An image output program characterized by The dot reference data includes
The threshold data is arranged in the first direction in the order of the low threshold, and the threshold data arranged in the first direction is further arranged so as to cover the remaining threshold data in the order of the low threshold.
The image output program according to claim 22. The dot reference data includes
The threshold data is arranged in an arrangement in which the growth in the first direction reaches a maximum when the mesh% is approximately 50%;
The image output program according to claim 22. 25. A storage medium in which the image output program according to claim 19 is stored so as to be readable by the image output control device.

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