JP2006050297A - Image output system, image output control device, image output method, image output program, and recording medium with the program stored - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform multiple value dot point processing for a non-photographic image, such as characters, figures, etc., and perform high quality printing which draws sharply the peripheral edge of the non-photographic image, when the half-tone image is output. <P>SOLUTION: The device analyzes image data containing a non-photograph image, extracts vector data of the non-photograph image, and perform RIP processings and dot-point processings. Furthermore, it draws the peripheral edge of the non-photograph image with a non-dot point, line by extracting a pixel group corresponding to the peripheral edge of the non-photographic image contained in the image data performed RIP processing and dot-point processing, and switching the extracted pixel group to a group with output. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a halftone process for image data received from an external device and transmits the image data to an image output apparatus having a relatively low resolution. Regarding the method.

  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, since the CTP, which is the final image output device described above, expresses gradation (shading) with the size of a halftone dot area, such a color laser printer is used for creating a DCP. In this case, it is preferable to perform gradation expression of the image data by halftone dots in the same manner as the image processing performed on the CTP.

  In this case, it is important to reproduce the edges of non-photographic image objects such as characters and figures sharply. For this purpose, for example, an image processing apparatus described in JP-A-8-23441 is used. In addition, a binary image region such as a character or a figure and a halftone image region such as a photo or a halftone dot are identified, and corresponding to each, simple binarization processing, smoothing processing, and pseudo halftone processing, It has been proposed to perform appropriate processing such as pseudo halftone processing.

Japanese Patent Laid-Open No. 5-48857 (paragraphs [0011]-[0070], FIGS. 1 to 12) JP-A-8-23441 (paragraphs [0010]-[0034], FIGS. 1 to 4)

  However, in a non-photographic image object such as a character or a figure, there are many incomplete halftone dots that cannot be reproduced as one complete halftone dot at the edge due to restrictions on halftone dot arrangement, as shown in FIG. . In the color laser printer as described above, since the reproducibility of small halftone dots is poor and is easily lost on the paper surface, these incomplete halftone dots are difficult to reproduce on the paper surface. Therefore, when a non-photo image object is output by a color laser printer, the output non-photo image object has a problem that the edge lacks sharpness and smoothness when viewed as shown in FIG. there were.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a non-halftone line in which the edge of a non-photographic image object such as a character or a figure is a non-halftone line. Image output system, control device, image output method, image output program, and program capable of performing high-quality printing in which the edge of the non-photographic image object is sharply drawn Is to provide a storage medium storing the. In addition, when multi-value halftone processing is performed and a halftone image is output with sufficient gradation, further high-quality printing can be achieved by bordering with a non-halftone line that is compatible with non-photographic image objects. It aims to make it possible to do.

  In order to solve the above problems, the invention described in claim 1 is an image output system that generates halftone dot image data from image data and outputs a halftone dot image based on the halftone dot image data. A vector data extracting unit that analyzes image data including an image and extracts vector data of the non-photographic image, a raster image generating unit that performs RIP processing on the image data to generate raster image data, and a matrix And halftone dot reference data storage means for storing halftone dot reference data in which predetermined threshold data is arranged, and the halftone dot reference data corresponding to the pixel groups in each range of the raster image data to constitute the pixel group Raster image data is generated by comparing the pixel density value data with the threshold value data of the halftone dot reference data and defining the output of each pixel. Halftone dot processing means for generating halftone dot image data, pixel extraction means for extracting a pixel group corresponding to the edge of the non-photographic image included in the halftone image data based on the vector data, Halftone dot image data rewriting means for bordering the edge of the non-photographic image with a non-halftone dot line by rewriting the output corresponding to the pixel group extracted by the pixel extracting means to be present, and the non-photographic image Image output means for outputting a halftone dot image whose edges are bordered by the non-halftone lines.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the non-halftone dot line has a width equal to a width of a halftone dot forming a margin of the non-photographic image. .

  The invention according to claim 3 is the invention according to claim 1, wherein the halftone dot reference data storage means stores halftone dot reference data in which a plurality of matrices are arranged according to the number of variable stages of output intensity, The halftone dot processing means further defines output intensity for each pixel constituting the halftone dot based on halftone dot reference data in which a plurality of matrices are arranged, and generates multi-value halftone dot image data. The halftone dot image data rewriting means further acquires density value data of pixels constituting the non-photographic image, converts the acquired density data into output intensity, and sets the density of the non-halftone line to the density value. It is defined by output intensity.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the non-photographic image includes a character, a graphic, or a combination thereof.

  The invention according to claim 5 is an image output control device that generates halftone dot image data from image data and causes the image output device to output an image based on the halftone dot image data. A vector data extracting means for analyzing the image data including the non-photo image data, a raster image generating means for performing RIP processing on the image data to generate raster image data, and a matrix Pixel reference data storage means for storing dot reference data in which predetermined threshold data is arranged, and pixels constituting the pixel group by associating the dot reference data with the pixel groups in each range of the raster image data The halftone dot data is compared with the threshold value data of the previous halftone dot reference data, and one halftone dot is generated by defining the presence or absence of the output of each pixel. Halftone dot processing means for generating halftone dot image data, pixel extraction means for extracting a pixel group corresponding to the edge of the non-photographic image included in the halftone image data based on the vector data, Halftone dot image data rewriting means for bordering the edge of the non-photographic image with a non-halftone line by rewriting the output corresponding to the pixel group extracted by the pixel extracting means to be present; and the halftone image And transmission means for adding output control information to the halftone image data rewritten by the data rewriting means and transmitting it to the image output device.

  The invention according to claim 6 is the invention according to claim 5, wherein the non-halftone dot line has a width equal to a width of a halftone dot forming a margin of the non-photographic image. .

  The invention according to claim 7 is the invention according to claim 5, wherein the halftone dot reference data storage means stores halftone dot reference data in which a plurality of matrices are arranged according to the number of variable stages of output intensity, The halftone dot processing means further defines output intensity for each pixel constituting the halftone dot based on halftone dot reference data in which a plurality of matrices are arranged, and generates multi-value halftone dot image data. The halftone dot image data rewriting means further acquires density value data of pixels constituting the non-photographic image, converts the acquired density data into output intensity, and sets the density of the non-halftone line to the density value. It is defined by output intensity.

  The invention described in claim 8 is characterized in that, in the invention described in claim 5, the non-photographic image includes a character, a graphic, or a combination thereof.

  The invention according to claim 9 is an image output method for generating halftone dot image data from image data and outputting a halftone dot image based on the halftone dot image data. Is stored, the image data including the non-photo image is analyzed, the vector data of the non-photo image is extracted, and RIP processing is performed on the image data to generate raster image data The halftone dot reference data is made to correspond to the pixel groups in each range of the raster image data, and the density value data of the pixels constituting the pixel group is compared with the threshold value data of the halftone dot reference data. Generating one halftone dot by defining the presence or absence of the output, generating halftone dot image data from raster image data, and based on the vector data, the non-photograph image included in the halftone dot image data A pixel group corresponding to the edge of the non-photographic image is extracted, and the output corresponding to the extracted pixel group is rewritten to be present, whereby the edge of the non-photographic image is trimmed with a non-halftone line, and the edge of the non-photo image is A halftone image in which a border is trimmed by the non-halftone dot line is output.

  The invention described in claim 10 is characterized in that, in the invention described in claim 9, the non-halftone dot line has a width equal to a width of a halftone dot forming a margin of the non-photographic image. .

  The invention of claim 11 is the invention of claim 9, wherein the halftone dot reference data stored in advance is halftone dot reference data in which a plurality of matrices are arranged according to the number of variable stages of output intensity, In the generation of halftone dot image data, multi-value halftone dot image data is generated by defining the output intensity for each pixel constituting the halftone dot based on the halftone dot reference data in which a plurality of matrices are arranged. In the rewriting of halftone dot image data, the density value data of the pixels constituting the non-photographic image is acquired, the acquired density data is converted into output intensity, and the density of the non-halftone line is changed. It is defined by the output intensity.

  The invention described in claim 12 is the invention described in claim 9, wherein the non-photographic image includes a character, a graphic, or a combination thereof.

  According to a thirteenth aspect of the present invention, halftone dot image data is generated from image data for an image output control apparatus configured by a computer that stores halftone dot reference data in which predetermined threshold data is arranged in advance in a matrix. An image output program for executing a process for performing the processing to analyze the image data including a non-photographic image and to extract vector data of the non-photographic image, and RIP processing is performed to generate raster image data, and halftone dot reference data is made to correspond to 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 pixels Comparing with threshold value data of halftone dot reference data, one halftone dot is generated by specifying the output of each pixel, and halftone dot image is created from raster image data. A process of generating data is executed, and a process of extracting a pixel group corresponding to a border of the non-photographic image included in the halftone image data is executed based on the vector data. An image output device which executes processing for bordering the edge of the non-photographic image with a non-halftone line by rewriting the corresponding output to be present, and adds output control information to the rewritten halftone image data It is characterized in that the process of transmitting to is executed.

  The invention described in claim 14 is characterized in that, in the invention described in claim 13, the non-halftone dot line has a width equal to a width of a halftone dot forming a margin of the non-photographic image. .

  The invention of claim 15 is the invention of claim 13, wherein the halftone dot reference data stored in advance is halftone dot reference data in which a plurality of matrices are arranged according to the number of variable stages of output intensity, In the generation of halftone dot image data, multi-value halftone dot image data is generated by defining the output intensity for each pixel constituting the halftone dot based on the halftone dot reference data in which a plurality of matrices are arranged. In the rewriting of halftone dot image data, the density value data of the pixels constituting the non-photographic image is further acquired, the acquired density data is converted into output intensity, and the non-halftone dot data is converted. A process of defining the line density by the output intensity is executed.

  The invention described in claim 16 is the invention described in claim 13, characterized in that the non-photographic image includes characters, figures, or a combination thereof.

  According to a seventeenth aspect of the present invention, the image output program according to any one of the thirteenth to sixteenth aspects is stored so as to be readable by the image output control device.

  According to the image output system, the image output control device, the image output method, the image output program, and the storage medium storing the program according to the present invention, halftone processing is performed on raster image data including non-photographic images. The edge of the non-photographic image is sharply drawn with a non-halftone dot line, so that high-quality printing can be performed. Further, the output intensity of the non-halftone line is set to the output intensity based on the density of the non-photographic image, and the width of the non-halftone line is set to be equal to the width of the halftone dot constituting the edge of the non-photographic image. Thus, it is possible to perform higher quality printing without making the non-halftone line noticeable.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred embodiments of an image output system, an image output control device, an image output method, an image output program, and a storage medium storing the program according to the present invention will be specifically described below 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 that is an image output control device for outputting comp image data, and a color laser printer 3 that is an image output device, A CTP RIP 4 and CTP 6 for CTP, a DCP control device 5 for DCP, and a DCP creation device 7 are provided by network connection.

  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 output device such as CTP6, DCP creation device 7 or color laser printer 3, that is, This is a conversion to bitmap data, which is a collection, so-called rasterization. In this embodiment, when the color laser printer 3 is used for DCP or CTP, the image data for printing is only subjected to vectorization of character fonts and page imposition processing for CTP output. Will remain.

  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 to extract vector data of the non-photographic image object. , RIP processing is performed. Further, a halftoning process for converting raster image data into halftone image data and a non-photographic image object bordering process described later are performed. 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 receiving the image data analyzes the image data and generates a vector of the non-photographic image object. After the data is extracted, the image data is subjected to RIP processing to be converted into raster image data, and the raster image data is subjected to halftone processing to be converted into halftone image data. Is transmitted to the color laser printer 3 together with the 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. Do. That is, the RIP process is not performed, and the vector image is transmitted to the control device 2 as it is. Receiving this, the control device 2 extracts vector data from the printing image data, and then performs RIP processing and halftone processing, and performs border processing at a location corresponding to the non-photographic image object (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, halftone processing, and border processing on the print image data transmitted from the CTP RIP 4, and sets the edges of the non-photographic image object with non-dot lines. This is a device that generates halftone dot image data, adds output control information, and transmits it to the color laser printer 3.

  That is, the control device 2 includes an image data storage unit 20 that stores print image data. In addition, the image data analysis processing unit 21 that performs RIP processing, the halftone dot reference data storage unit 22 that performs halftone processing, and the halftoning unit 23 include a vector data extraction unit 27 and an image extraction unit that perform edge processing. 24 and a halftone dot image data rewriting unit 25, and a transmission unit 26 that transmits halftone dot image data to the color laser printer 3. The image data storage unit 20 and the vector data extraction unit 27 are configured by the RAM of the control device 2, the halftone dot reference data storage unit 22 is configured by the HDD, and the other units are image stored in the ROM or the HDD. It is configured by the CPU performing calculations based on the output program. 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. This print image data includes a non-photographic image object and a photographic image object, and the non-photographic image object is vectorized with a character font or the like.

  The image data analysis processing unit 21 analyzes the printing image data and performs RIP processing. For the analysis, the description contents of the printing image data are sequentially read out to analyze whether or not the non-photographic image object is included in the printing image data. Extract vector data of a photographic image object. Further, raster image data is generated by sequentially performing RIP processing.

  The raster image data is bitmap data composed of pixels that match the output resolution of the color laser printer 3. Each pixel of raster image data is assigned predetermined density value data according to the density of the image. Such raster image data exists for each color plate corresponding to CMYK and special colors (hereinafter also referred to as “special colors”) 1 and 2 such as gold and silver. As the density value data, for example, numerical values of 0 to 255 of 256 gradations are applied as shown in FIG. In other words, the image data analysis processing unit 21 serves as a raster image generation unit that generates raster image data by performing RIP processing on the 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.

  Each threshold value data is allocated to each threshold value matrix based on the shape, angle, number of lines, and density of halftone dots. In this embodiment, as shown in FIG. 4B, the threshold matrix of each output intensity is 4 × 4, and the number of variable stages of the output intensity of the color laser printer 3 is five. There is another threshold matrix. 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.

  The halftone dot conversion unit 23 applies the halftone dot reference data to the raster image data for each color plate in accordance with the RIP processing sequentially performed by the image data analysis processing unit 21 to form halftone dots sequentially, and for each color plate. 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.

  Upon receiving the presence of the non-photo image object, the vector data extraction unit 27 interrupts the operation of the image data analysis processing unit 21 and extracts the vector data of the non-photo image object. This vector data is data indicating the edges of non-photographic image objects such as characters and graphics. That is, the vector data extraction unit 27 serves as a vector data extraction unit that analyzes image data including a non-photographic image and extracts vector data of the non-photographic image.

  When the vector data is extracted by the vector data extraction unit 27, the image extraction unit 24 extracts pixels corresponding to the vector data by following the RIP processing and the halftone processing that are sequentially performed. In the image extraction, the start point and end point of a vector representing the edge of a non-photographic image object are calculated based on the vector data, and a linear expression between the start point and end point of the vector is calculated. Then, as shown in FIG. 6A, pixels located on the calculated linear expression and pixels within a predetermined range are extracted from the pixels. The range in which the pixels are extracted is a range having a width equivalent to the diameter of one halftone dot constituting the edge of the non-photographic image object. That is, the image extracting unit 24 serves as a pixel extracting unit that extracts a pixel group corresponding to the edge of the non-photographic image included in the halftone image data based on the vector data.

  The halftone image data rewriting unit 25 rewrites all the output data of the pixel group extracted by the image extracting unit 24 to output data that defines the presence of output, and defines a predetermined output intensity for the extracted pixel group. . The output data in rewriting is determined by converting the density of the pixels of the non-photographic image object into the output intensity. For example, when the non-photo image object is represented by 256 gradations, the density value data of the pixels of the non-photo image object is divided by 256 and multiplied by the variable number of output intensity levels set in the color laser printer 3. As a result, the output data is determined.

  When the extracted pixel group is rewritten with output, as shown in FIG. 6B, the edge of the non-photographic image object is bordered by a non-halftone line constituted by the pixel group with output. Become. Further, by painting out the pixel group extracted based on the converted output intensity, it is possible to frame with a non-halftone line similar to the color of the halftone dot constituting the non-photographic image object. That is, the halftone dot image data rewriting unit 25 rewrites the output corresponding to the extracted pixel group to be present, and halftone dot image data rewriting means for bordering the edge of the non-photographic image with the non-halftone line. Become.

  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 image data for printing is simultaneously subjected to RIP processing to become raster image data, and the raster image data is subjected to halftoning processing to become halftone dot image data. The portion corresponding to the edge becomes halftone dot image data which is rewritten by being edged with a non-halftone line. Eventually, halftone image data bordered by non-halftone lines is completed. Each processing is performed on all the print image data for each color plate of CMYK and special colors 1 and 2.

  The transmission unit 26 adds output control information to the halftone dot image data for each color plate that has been rewritten and finally completed by the halftone dot image data rewriting unit 25, and adds the output control information to the color laser printer 3. Send. In other words, the transmission unit 26 serves as a transmission unit that adds output control information to the halftone image data rewritten by the halftone image data rewriting unit and transmits the output control information to the image output 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. When the image output program is activated, the image data analysis processing unit 21 sequentially reads the description contents of the print image data and analyzes whether or not a non-photographic image object exists (S20).

  If there is no non-photographic image object in the read description content (S20, NO), the read description content is subjected to RIP processing, and the data subjected to RIP processing is passed to the halftone dot conversion unit 23 to generate a network. If the description content is not the end of the image data (S27, NO), the description content of the next print image data is read to determine whether or not the non-photographic image object exists again. Analyze (S20).

  If there is a non-photographic image object in the description content of the read print image data (S20, Yes), the vector data extraction unit 27 interrupts the analysis and RIP processing of the image analysis processing unit 21, and the vector of the non-photographic image object Data is extracted and held (S21). At the same time, the density value data of the non-photographic image object is also extracted. In this embodiment, as shown in FIG. 4A, the density value data of the non-photographic image object is 105, and this data is extracted and held.

  When the vector data is extracted, the image analysis processing unit 21 performs RIP processing on the description contents of the read print image data, and generates raster image data for each color plate. Then, the raster image data is transferred to the halftone dot forming unit 23, and a halftone dot forming process is performed (S22).

  In the present embodiment, as shown in FIG. 4, in the pixel group transferred to the halftone dot unit 23, 105 is assigned to each pixel as density value data. 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. . Each threshold matrix is applied to the pixel group shown in FIG. 4A, each threshold data is compared with the density value data, and the threshold data belonging to the threshold matrix of the maximum output intensity among the threshold data that exceeds the density value data. Adopted. Then, output data based on the output intensity of the threshold matrix to which the adopted threshold data belongs is described in 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.

  When multi-value halftone dot image data is generated from the read data in this way, the halftone dot image data is transferred to the image extraction unit 24. The image extraction unit 24 reads the vector data held by the vector data extraction unit 27 and the density value data of the non-photographic image object, and calculates a linear expression between the start point and the end point of the vector from the vector data (S23). The calculated linear equation corresponds to the edge of the non-photographic image object as shown in FIG. Then, all pixels on the straight line are extracted with a width corresponding to one halftone dot.

  The extracted pixel group information is transferred to the halftone image data rewriting unit 25 together with the density value data and the halftone image data (S24). The halftone image data rewriting unit 25 first converts the density value data of the non-photographic image object, 105 in the present embodiment, into output intensity. In the present embodiment, the gradation of the print image data is 256 gradations, and the number of variable stages of the output intensity of the color laser printer is 5. Therefore, 105 is divided by 256 and multiplied by 5. Then, 2 is calculated using the integer part of the calculated value as output data (S25).

  Next, all the extracted pixel groups are filled with output data indicating that there is an output (S26). In this case, the output data is rewritten so that all the extracted pixel groups are filled with the calculated output intensity of 2. As shown in FIG. 6 (a), all the extracted pixel groups are output with an output intensity of 2, and as shown in FIG. 6 (b), non-halftone lines are formed in these pixel groups. This non-halftone dot line is a line that borders the edge of the non-photographic image object. As described above, the edge of the non-photographic image object in the halftone image data is bordered by the non-halftone line, and the halftone image data is rewritten in the read description content.

Then, it is determined whether the rewritten halftone image data is located at the end of the printing image data (S27). If it is not the end (S28, NO), the image data analysis processing unit 21 receives the image data from the image data storage unit 20. The next description content of the print image data is read, and the above operation is repeated until the end of the print image data. When the printing image data is repeated up to the end (S27, Yes), rewritten halftone image data in one color plate is generated. This process is repeated for each color plate to generate halftone dot image data for each color plate in which the edge of the non-photographic image object is bordered by a non-halftone line.
As a result, the edge of the non-photographic image object is bordered by the non-halftone line, and high-quality printing in which the edge of the non-photographic image object is drawn sharply can be performed. As described above, the width of the non-halftone line that borders the edge of the non-photographic image object is set to be exactly the same as the width of one halftone dot, so it is too thin to be drawn properly. There is also no such thing as being too fat and noticeable.

  The rewritten halftone image data for each color plate is output to the color laser printer 3 with output control information added by the transmission unit 26, and the edge of the non-photographic image object is non-photographed in the color laser printer 3. An image bordered by a halftone dot line is output. At this time, the non-halftone dot line for each color plate is mixed, whereby the edge of the non-photographic image object is bordered by a line that is very similar in both density and color, and the image quality is improved.

  With such a configuration, a halftone dot image based on halftone dot image data for each color plate composed of basic colors is output on the transfer paper with a relatively low resolution but sufficient gradation. However, as described above, the edge of the non-photo image object is bordered by a non-halftone line, so that high-quality printing in which the edge of the non-photo image object is drawn sharply can be performed. it can.

  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. .

  In addition, the color proof production 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. FIG. 4 is an explanatory diagram regarding halftone doting in the image output processing in the control device, (A) is a diagram showing raster image data obtained by RIP processing printing image data, and (B) is a halftone dot reference. It is a figure which shows data, (C) is a figure which shows halftone dot image data. FIG. 4 is a flowchart for explaining a flow of image output processing in the control device shown in FIG. 3. FIG. It is explanatory drawing of the border process which borders the edge of the non-photographic image object in a control apparatus, (a) is a border processing example of an example, (b) is the enlarged view. It is a figure which shows the state by which the conventional non-photographic image object was halftone-dotted. It is a figure which shows the state which looked at the conventional non-photographic image object made into the halftone dot.

Explanation of symbols

2 control device 20 image data storage unit 21 image data analysis processing unit 22 halftone dot reference data storage unit 23 halftone dot conversion unit 24 image extraction unit 25 halftone dot image data rewriting unit 26 transmission unit 27 vector data extraction unit 3 color laser printer

Claims (17)

An image output system for generating halftone dot image data from image data and outputting a halftone dot image based on the halftone dot image data,
A vector data extracting means for analyzing image data including a non-photographic image and extracting vector data of the non-photographic image;
Raster image generating means for generating raster image data by performing RIP processing on the image data;
Halftone dot reference data storage means for storing halftone dot reference data 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 Generating halftone dots by defining the presence or absence of halftone dots, halftone dot processing means for generating halftone dot image data from raster image data,
Pixel extraction means for extracting a pixel group corresponding to a margin of the non-photographic image included in the halftone image data based on the vector data;
Halftone dot image data rewriting means for bordering the edge of the non-photographic image with a non-halftone line by rewriting the output corresponding to the pixel group extracted by the pixel extracting means to be
Image output means for outputting a halftone image in which the edge of the non-photographic image is bordered by the non-halftone line;
Providing
An image output system characterized by The non-halftone line is
The width is equal to the width of the halftone dots forming the edges of the non-photographic image;
The image output system according to claim 1. The halftone dot reference data storage means stores halftone dot reference data in which a plurality of matrices are arranged according to the number of output intensity variable stages,
The halftone dot processing means includes:
Furthermore, based on halftone dot reference data in which a plurality of matrices are arranged, the output intensity is defined for each pixel constituting the halftone dot, and multi-value halftone dot image data is generated,
The halftone dot image data rewriting means is
Further, acquiring density value data of pixels constituting the non-photographic image, converting the acquired density data into output intensity, and defining the density of the non-halftone line with the output intensity,
The image output system according to claim 1. The non-photographic image includes characters or figures or a combination thereof;
The image output system according to claim 1. An image output control device that generates halftone dot image data from image data and causes an image output device to output an image based on the halftone dot image data,
A vector data extracting means for analyzing image data including a non-photographic image and extracting vector data of the non-photographic image;
Raster image generating means for generating raster image data by performing RIP processing on the image data;
Halftone dot reference data storage means for storing halftone dot reference data 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, and the density value data of the pixels constituting the pixel group and the threshold value data of the previous halftone dot reference data are compared, and One halftone dot is generated by defining the presence or absence of output, halftone dot processing means for generating halftone dot image data from raster image data,
Pixel extraction means for extracting a pixel group corresponding to a margin of the non-photographic image included in the halftone image data based on the vector data;
Halftone dot image data rewriting means for bordering the edge of the non-photographic image with a non-halftone line by rewriting the output corresponding to the pixel group extracted by the pixel extracting means to be
Transmission means for adding output control information to the halftone dot image data rewritten by the halftone dot image data rewriting means and transmitting it to the image output device;
Providing
An image output control device characterized by the above. The non-halftone line is
The width is equal to the width of the halftone dots forming the edges of the non-photographic image;
The image output control device according to claim 5, wherein The halftone dot reference data storage means stores halftone dot reference data in which a plurality of matrices are arranged according to the number of output intensity variable stages,
The halftone dot processing means includes:
Furthermore, based on halftone dot reference data in which a plurality of matrices are arranged, the output intensity is defined for each pixel constituting the halftone dot, and multi-value halftone dot image data is generated,
The halftone dot image data rewriting means is
Further, acquiring density value data of pixels constituting the non-photographic image, converting the acquired density data into output intensity, and defining the density of the non-halftone line with the output intensity,
The image output control apparatus according to claim 5. The non-photographic image includes characters or figures or a combination thereof;
The image output apparatus according to claim 5. An image output method for generating halftone dot image data from image data and outputting a halftone dot image based on the halftone dot image data,
Store dot reference data in which predetermined threshold data is arranged in a matrix in advance,
Analyzing image data including a non-photographic image, extracting vector data of the non-photographic image,
RIP processing is performed on the image data to generate raster image data,
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 is compared with the threshold value data of the halftone dot reference data, and the output of each pixel One dot is generated by specifying the presence or absence of, and dot image data is generated from raster image data,
Based on the vector data, extract a pixel group corresponding to the edge of the non-photographic image included in the halftone image data;
By rewriting the output corresponding to the extracted pixel group to have a border of the non-photographic image with a non-halftone line,
Outputting a halftone image in which the edge of the non-photographic image is bordered by the non-halftone line;
An image output method characterized by the above. The non-halftone line is
The width is equal to the width of the halftone dots forming the edges of the non-photographic image;
The image output method according to claim 9. The halftone dot reference data stored in advance is halftone dot reference data in which a plurality of matrices are arranged according to the number of output intensity variable stages.
In the generation of halftone dot image data,
Furthermore, based on halftone dot reference data in which a plurality of matrices are arranged, the output intensity is defined for each pixel constituting the halftone dot, and multi-value halftone dot image data is generated,
In rewriting halftone image data,
Further, acquiring density value data of pixels constituting the non-photographic image, converting the acquired density data into output intensity, and defining the density of the non-halftone line with the output intensity,
The image output method according to claim 9. The non-photographic image includes characters or figures or a combination thereof;
The image output method according to claim 9. An image output program for executing processing for generating halftone dot image data from image data to an image output control device configured by a computer storing halftone dot reference data in which predetermined threshold data is arranged in advance in a matrix. There,
In the image output control device,
Analyzing image data including a non-photographic image, and executing a process of extracting vector data of the non-photographic image,
A process of generating raster image data by performing RIP processing on the image data;
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 is compared with the threshold value data of the halftone dot reference data, and the output of each pixel By creating a halftone dot by specifying the presence or absence of, the process of generating halftone dot image data from the raster image data,
Based on the vector data, to execute a process of extracting a pixel group corresponding to the edge of the non-photographic image included in the halftone image data,
By rewriting the output corresponding to the extracted pixel group to have a non-half-tone line bordering process on the non-photographic image,
Adding output control information to the rewritten halftone dot image data and transmitting it to the image output device;
An image output program characterized by The non-halftone line is
The width is equal to the width of the halftone dots forming the edges of the non-photographic image;
The image output program according to claim 13. The halftone dot reference data stored in advance is halftone dot reference data in which a plurality of matrices are arranged according to the number of output intensity variable stages.
In the generation of halftone dot image data,
Furthermore, based on halftone dot reference data in which a plurality of matrices are arranged, the output intensity is defined for each pixel constituting the halftone dot, and a process for generating multi-value halftone dot image data is executed,
In rewriting halftone image data,
Further, acquiring density value data of pixels constituting the non-photographic image, converting the acquired density data into output intensity, and executing a process of defining the density of the non-halftone line with the output intensity,
The image output program according to claim 13. The non-photographic image includes characters or figures or a combination thereof;
The image output program according to claim 13. 17. A storage medium in which the image output program according to claim 13 is stored so as to be readable by the image output control device.