JP2017182291A - Rasterization processing apparatus, rasterization processing method, and program - Google Patents

Abstract

An image resolution of image data included in page data is set to be equal to or higher than that of a printing press. Therefore, although the output resolution at the time of the first rasterization processing is appropriate, the resolution is high. A re-rasterization process for printing on another different printing machine has a problem because the output resolution is different. The image resolution of the image data included in the page data is compared with the output resolution of the rasterization condition. If “output resolution of the rasterization condition> image resolution”, the image type of the image data is obtained and Image quality degradation is suppressed by performing page data rasterization processing after performing image conversion based on image processing based on image type and processing that matches the image resolution with the output resolution of the rasterization condition. A suitable printing result can be obtained. [Selection] Figure 4

Description

  The present invention relates to a rasterization processing apparatus, a rasterization processing method, and a program for suppressing an image defect caused by a difference between the resolution of an image included in page data and the output resolution of rasterized data output by rasterization processing.

  2. Description of the Related Art A technique for creating a page that represents a printed material by using a page description language (hereinafter referred to as PDL) such as PostScript (trademark of Adobe Systems Inc.) or PDF (Portable Document Format) is well known.

  Since the page data created by the PDL describes the page configuration programmatically, a desired printed matter cannot be obtained even if the page data is printed as it is. In order to obtain a desired printed matter, a rasterizing process is required in which a page is described into an image format that can represent a page on a recording medium such as paper based on the description of page data.

  Even if the rasterization process is performed, the page data in the PDL format as the conversion source remains, so the page data is stored in an electronic medium or a magnetic medium, and a re-rasterization process is performed as necessary to obtain a printed matter. This is generally done by printing companies. This is because if the printing format is an inkjet method or an electrophotographic method, printing is performed without creating a printing plate. Even if a printing plate is created, if it exceeds the durability of the printing plate due to repeated printing, re-rasterization processing of the page data is required to create the printing plate again. .

  However, the printed matter obtained by the re-rasterization process on the page data may have a quality problem.

  For example, when re-rasterization processing is performed to print page data including a halftone image with an image resolution of 350 dpi with an inkjet printing apparatus with an output resolution of 600 dpi, the image included in the rasterized page has moire. It sometimes occurred. Alternatively, when re-rasterization processing is performed to print a multi-value image with an image resolution of 150 dpi with an inkjet printing apparatus with an output resolution of 720 dpi, the multi-value image included in the rasterized page is degraded in quality due to enlargement. There was a thing.

  This is because the image data included in the page data is set so that the image resolution is equal to or higher than the resolution of the printing press. In the re-rasterization process for printing on another different printing machine, the output resolution is different, which is a problem.

  In order to solve such a problem, it is conceivable to match the image resolution of the image data included in the page data with the output resolution at the time of the rasterizing process.

Patent Publication 2012-98986

  However, even if the image resolution of the image data included in the page data is simply matched with the output resolution at the time of the rasterizing process, a significant decrease in the image quality can be surely suppressed, but a decrease in the image quality still occurs.

  For example, when converting the resolution of a monochrome image with halftone dots from 350dpi to 600dpi, if the conversion is performed using the nearest neighbor method generally used for resolution conversion processing, the nearest dot value is adopted. This is because an intermediate value does not occur, and as a result, moire due to periodicity during resolution conversion is likely to occur. Or, when converting the resolution of a multi-valued image from 300dpi to 720dpi, depending on the interpolation processing of the pixels that make up the image, the pixels appear as they are, or the edges of the image become stepped, etc. As a result, the quality of the image is lowered.

  In order to solve the above-described problems, the present invention provides a rasterization capable of obtaining a preferable print result even when the image resolution of image data included in a page image is not suitable for the output resolution at the time of rasterization processing. It is an object of the present invention to provide a processing device, a rasterization processing method, and a program for executing the rasterization processing on a computer.

[Application Example 1]
A rasterization processing device that outputs rasterized data that can be output by a recording device from page data described in a page description language, and sets at least an output resolution of the rasterized data as a rasterization condition for outputting the rasterized data Rasterizing condition setting means for analyzing, page data analyzing means for analyzing the page data to identify content data included in the page data, and for displaying an image among the content data identified from the page data Image data resolution acquisition means for acquiring an image resolution representing the image from the image data, resolution comparison means for comparing the output resolution of the rasterization condition and the image resolution of the image data, and the resolution comparison means As a result of the comparison, the image data The image resolution of the image data is lower than the output resolution of the rasterization condition, image type acquisition means for acquiring the image type of the image data, image processing based on the image type, and matching the image resolution to the output resolution Image data conversion means for performing processing on the image data, and performing rasterization processing based on the page data including the image data converted by the image data conversion means in accordance with the rasterization conditions, the rasterized data And rasterized output means for outputting.

[Application Example 2]
In the rasterization processing apparatus, the image processing performed by the image data conversion means is a process for removing image defects generated when the image data is rasterized.

[Application Example 3]
A rasterization processing apparatus, wherein the image data conversion means includes image processing condition setting means for setting image processing conditions relating to the image processing.

[Application Example 4]
In the rasterization processing apparatus, when the image type of the image data is a binary image, the image data conversion means performs a moire reduction process as an image process.

[Application Example 5]
In the rasterization processing apparatus, when the image type of the image data is a multi-valued image, the image data conversion means performs high definition processing as image processing.

[Application Example 6]
A rasterization processing method for outputting rasterized data that can be output by a recording device from page data described in a page description language, wherein at least an output resolution of the rasterized data is set as a rasterizing condition for outputting the rasterized data A rasterizing condition setting step, a page data analysis step of analyzing the page data to identify content data included in the page data, and displaying an image of the content data identified from the page data An image data resolution acquisition step of acquiring an image resolution representing the image from the image data of the image, a resolution comparison step of comparing the output resolution of the rasterization condition and the image resolution of the image data, and the resolution comparison step As a result of the comparison, the image data The image resolution of the image data is lower than the output resolution of the rasterization condition, the image data type acquisition step of acquiring the image type of the image data, the image processing based on the image type, and the image resolution match the output resolution A rasterizing process based on the page data including the image data converted in the image data converting step according to the rasterizing condition, and performing the rasterizing process on the image data. And a rasterizing output step for outputting data.

[Application Example 7]
Rasterization processing for outputting rasterized data that can be output by a recording device from page data described in a page description language when the CPU of the computer executes in a memory in a computer having a display unit and an operation unit A program for realizing as an apparatus, wherein a rasterizing condition setting step for setting at least an output resolution of the rasterized data as a rasterizing condition for outputting the rasterized data, and analyzing the page data, A page data analysis step for identifying content data included in the image data, and an image data solution for obtaining an image resolution for expressing the image from image data for displaying an image among the content data identified from the page data. And a resolution comparison step for comparing the output resolution of the rasterization condition and the image resolution of the image data, and the result of the comparison in the resolution comparison step is that the image resolution of the image data is an output of the rasterization condition. If the image data is lower than the resolution, an image data type acquisition step for acquiring an image type of the image data, an image process based on the image type, and a process for matching the image resolution with the output resolution are performed on the image data. An image data conversion step performed in accordance with the rasterization conditions, and a rasterization output step of performing rasterization processing based on the page data including the image data converted by the image data conversion means and outputting the rasterized data. Prepare.

[Application Example 8]
In the program, the image processing performed in the image data conversion step is processing for removing an image defect generated when the image data is rasterized.

[Application Example 9]
A program, wherein the image data conversion step includes an image processing condition setting step for setting an image processing condition related to the image processing.

[Application Example 10]
When the image type of the image data is a binary image, the image data conversion step performs moiré reduction processing as image processing.

[Application Example 11]
When the image type of the image data is a multi-value image, the image data conversion step performs high definition processing as image processing.

  In Application Example 1, when the rasterization processing device compares the image resolution of the image data included in the page data with the output resolution of the rasterization condition, and if “image resolution <output resolution of the rasterization condition”, the image of the image data By performing image conversion that includes image processing based on the image type based on the image type and processing that matches the image resolution with the output resolution of the rasterization condition, and performing rasterization processing of the page data, It is possible to obtain a suitable printing result in which deterioration in quality is suppressed.

  In Application Example 2, since the image processing performed by the image data conversion unit of the rasterization processing apparatus is processing for removing image defects caused when the image data is rasterized, image quality is degraded by performing page data rasterization processing. It is possible to obtain a suitable printing result with suppressed.

  In Application Example 3, the image data conversion unit of the rasterization processing apparatus includes an image processing condition setting unit that sets an image processing condition related to the image processing. Therefore, the rasterization processing of the page data is appropriately performed according to the change of the printing condition. As a result, it is possible to obtain a suitable printing result in which deterioration in image quality is suppressed.

  In Application Example 4, the image data conversion unit of the rasterization processing device performs moire reduction processing as image processing when the image type of the image data is a binary image. Therefore, by performing rasterization processing of page data, It is possible to obtain a suitable printing result in which deterioration in quality is suppressed.

  In Application Example 5, the image data conversion unit of the rasterization processing apparatus performs high-definition processing as image processing when the image type of the image data is a multi-valued image. Therefore, by performing rasterization processing of page data, It is possible to obtain a suitable printing result in which deterioration of image quality is suppressed.

  In Application Example 6, the image resolution of the image data included in the page data is compared with the output resolution of the rasterization condition, and if “image resolution <output resolution of the rasterization condition”, the image type of the image data is acquired. Since this is a rasterization processing method for performing page data rasterization processing after performing image conversion based on the image processing based on the image type and processing for matching the image resolution with the output resolution of the rasterization condition, the image quality decreases. It is possible to obtain a suitable printing result with suppressed.

  In Application Example 7, the image resolution of the image data included in the page data is compared with the output resolution of the rasterization condition, and if “image resolution <output resolution of the rasterization condition”, the image type of the image data is acquired. Since image conversion based on the image type and image conversion that matches the image resolution with the output resolution of the rasterization condition is performed, the page data rasterization process is executed by the computer, resulting in a decrease in image quality. It is possible to obtain a suitable printing result with suppressed.

  In Application Example 8, since the image processing performed by the image data conversion step of the rasterizing process performed by the computer is a process of removing image defects caused when the image data is rasterized, the page data is rasterized and the image quality is improved. It is possible to obtain a suitable printing result in which the decrease is suppressed.

  In Application Example 9, since the image data conversion step of rasterization processing performed by the computer includes an image processing condition setting step for setting image processing conditions related to the image processing, the rasterization processing of the page data is appropriately performed according to the change of the printing conditions. As a result, it is possible to obtain a suitable printing result in which deterioration in image quality is suppressed.

  In Application Example 10, since the image data conversion step of the rasterization process performed by the computer performs the moire reduction process as the image process when the image type of the image data is a binary image, the rasterization process of the page data is performed. It is possible to obtain a suitable printing result in which deterioration of image quality is suppressed.

  In Application Example 11, since the image data conversion step of the rasterizing process performed by the computer performs a high-definition process as the image process when the image type of the image data is a multi-valued image, the page data rasterizing process is performed. Thus, it is possible to obtain a suitable printing result in which deterioration in image quality is suppressed.

1 is a configuration diagram of a rasterization processing device 1 according to a first embodiment of the present invention. 3 is a flowchart for explaining an operation performed in the rasterization processing device 1 according to the first embodiment of the present invention. It is explanatory drawing about the structure of the page data of this invention. FIG. 5 is a diagram for explaining image processing on image data in the rasterization processing device 1 according to the first embodiment of the present invention. It is a figure for demonstrating condition setting menu JS. FIG. 5 is a diagram for explaining rasterized data created from page data by the rasterizing processing apparatus 1 according to the first embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
FIG. 1 is a diagram for explaining the configuration of a rasterization processing apparatus 1 according to the present invention. The rasterization processing apparatus 1 is a commonly used personal computer, and includes a CPU 11, a display unit 12, an input unit 13, a network I / F 14, a media drive 15, a storage unit 16, and a memory 17.

  The CPU 11 controls the entire rasterization processing device 1 and realizes the function of the rasterization processing device 1 by executing the program P recorded in the media disk 18 inserted in the media drive 15 in the memory 17 in particular. .

  The display unit 12 is used to display information necessary for rasterization processing. The input unit 13 includes a mouse and a keyboard, and is used by an operator to input an instruction to the rasterization processing device 1.

  The network I / F 14 is for connecting the rasterization processing apparatus 1 and a network (not shown). Via the network I / F 14, the rasterization processing apparatus 1 receives information necessary for rasterization processing, such as page data to be rasterized, rasterization setting data for performing rasterization processing, from a terminal (not shown) connected to the network. Can be received.

  It is also possible to download a program P that realizes the functions of the rasterization processing device 1 from a server (not shown). Further, when an output device (not shown) is connected to the rasterization processing device 1 via a network, rasterized data can be transmitted to the output device via the network I / F 14.

  The media drive 15 is used for reading the program P recorded on the media disk 18. The function of the rasterization processing device 1 is realized by the program P read by the media drive 15. The media disk 18 is a non-transitory portable recording medium such as an optical disk such as a CD-ROM, DVD-ROM, CD-R, DVD-RAM, or a semiconductor memory such as a USB memory, and the media drive 15 is a medium. A read / write mechanism corresponding to the disk 18 is provided.

  The page data or rasterization setting data required for the rasterization process may be recorded on the media disk 18 and taken into the rasterization processing apparatus 1 from the media drive 15. Alternatively, the media drive 15 may be used to record the rasterized data generated by the rasterization processing device 1 on the media disk 18.

  The storage unit 16 stores the program P read by the media drive 15. The storage unit 16 also stores rasterization setting data, page data, or rasterized data.

  The memory 17 is a work area for the CPU 11 to execute the program P stored by the storage unit 16. As a result of execution of the program P by the CPU 11, in the memory 17, a rasterization condition setting unit 171, a page data analysis unit 172, an output resolution-image data resolution comparison unit 173, an image data conversion unit 174, and a rasterization processing unit 175 are realized. .

  The rasterization condition setting unit 171 sets rasterization conditions used when the rasterization processing apparatus 1 performs rasterization processing on page data to generate rasterized data. As rasterization conditions set by the rasterization condition setting unit 171, there is an output resolution of rasterized data. Rasterization conditions are also set as rasterization conditions such as C (cyan), M (magenta), Y (yellow), K (black), color settings for rasterized data to be printed, such as special colors, and network types such as AM / FM. Set in the unit 171.

  The page data analysis unit 172 analyzes page data to be rasterized by the rasterization processing device 1. The analysis of page data means identifying the presence / absence of an error in page data and the type of content used to represent the page. The contents used for page data PD include CT image files (CT image data) for expressing multi-valued images such as JPEG files and GIF files, and 1-bit TIFF files for expressing 1-bit images that are already halftone ( In addition to image data such as (binary image data), there are txt files (text data) for expressing characters. The page data analysis unit 172 analyzes the page data and identifies content included in the page data in order to perform optimal image conversion in image conversion described later.

  The page data analysis unit 172 further includes an image data resolution acquisition unit 1721. The image data resolution acquisition unit 1721 acquires image resolutions for expressing images set in the image data identified by the page data analysis unit 172, respectively. The image resolution acquired by the image data resolution acquisition unit 1721 is used for comparison processing by an output resolution-image resolution comparison unit 173 described later.

  The output resolution-image resolution comparison unit 173 compares the output resolution of the rasterization condition set by the rasterization condition setting unit 171 with the image resolution of the image data included in the page data acquired by the image data resolution acquisition unit 1721. When the output resolution of rasterized data and the image resolution of image data do not match, especially when the image data resolution is lower than the output resolution of rasterized data, it is possible to represent images in rasterized data obtained by rasterizing page data. Problems such as moiré occur. In order to prevent such a problem from occurring, the output resolution-image resolution comparison unit 173 compares the output resolution of the rasterization condition with the image resolution of the image data, and the comparison result indicates that the image resolution of the image data is the output resolution of the rasterization condition. If lower than that, the image data conversion unit 174, which will be described later, performs image data conversion processing with resolution conversion.

  The image data conversion unit 174 performs image data conversion processing with resolution conversion when the image resolution of the image data included in the page data is lower than the output resolution of the rasterization condition. The image data conversion process performed by the image data conversion unit 174 is intended to improve image quality such as moire removal resulting from the rasterization process. As the resolution conversion, bilinear, bicubic (high) bicubic (super), super-resolution processing, and the like are performed based on the type of image data. In addition, as image conversion, filter processing for the purpose of noise removal such as a Gaussian filter and a Mitian filter, or supersampling with anti-aliasing is performed.

  The image data conversion unit 174 includes a binary image conversion unit 1741 and a multi-value image conversion unit 1742 in order to perform image data conversion for each type of image data included in the page data.

  The binary image data conversion unit 1741 converts image data when the image data included in the page data is a binary image such as a 1-bit TIFF file and the image resolution of the image data is lower than the resolution of the rasterized output. As a result of identifying the image data included in the page data by the page data analysis unit 172, if the resolution of the image data is lower than the output resolution of the rasterization condition as a result of the binary image, the binary image data conversion unit 1741 Image conversion with resolution conversion is performed on the data.

  The image conversion performed by the binary image data conversion unit 1741 converts the image resolution of the image data to a resolution higher than the output resolution of the rasterization condition, performs anti-aliasing processing, and then supersampling to match the output resolution of the rasterization condition, or One of the filtering processes performed after the image resolution of the image data is matched with the output resolution of the rasterization condition.

  The multi-value image data conversion unit 1742 converts image data when the image data included in the page data is a multi-value image such as a CT image file and the image data has a lower image resolution than the rasterized output.

  The image conversion performed by the multi-value image data conversion unit 1742 is a filter process performed after matching the image resolution of the image data with the output resolution of the rasterization condition.

  The converted image data converted by the image data conversion unit 174 is sent to a rasterization processing unit 175 described later.

  The rasterization processing unit 175 performs drawing with reference to the description of the page data based on the rasterization conditions set by the rasterization condition setting unit 171 to generate rasterized data. In addition, the rasterization processing unit 175 performs rasterization processing by replacing the converted image data converted by the image data conversion unit 174 with the image data included in the page data.

  The rasterized data generated by the rasterization processing unit 175 is stored in the storage unit 16 and used for output processing as necessary.

  FIG. 2 is a diagram for explaining the page data PD that is to be subjected to rasterization processing by the rasterization processing device 1. FIG. The page data PD is created by PDL such as PostScript or PDF.

  FIG. 2A is a diagram for showing a print image represented by the page data PD. Originally, margins, accessories, and the like necessary for creating a printed material are also arranged, but they are omitted here for explanation.

  In the page data PD shown in FIG. 2A, the page size is set to A4 length 210 mm × 297 mm in order to print on A4 size paper. Within this A4 size area, image 1 (img1) with the lower left point as the offset position O1 with respect to the origin O, similarly image 2 (img2) with the lower left point as the offset position O2, and lower left point as the offset position O3 Text 1 (txt1) is placed, and when printing is performed on A4 vertical print paper based on the rasterized data obtained by performing rasterization processing on the page data PD, the printed matter shown in FIG. Can be obtained.

  FIG. 2 (b) is a diagram for illustrating the description of the page data PD. Based on the description of the page data PD, rasterization processing by the rasterization output unit 175 is performed.

  FIG. 2 (b) is described in PDL, which is expressed in a markup language in which styles are defined by tags. Between tag <PD> and </ PD> that declares page data PD, page size, type of content that composes page, content size, offset, number of ink colors used, resolution, etc. It is described.

  In the description of the page data PD shown in FIG. 2B, a tag <size> indicating the page size is described after the declaration tag. Here, since it is A4 vertical, “<size> A4, Vertical </ size>” is described, which describes that the page size of the page data PD is A4 vertical.

  Subsequently, the content arranged in the page is described. The tag indicating the content is <obj>, and here, image 1, image 2, and text 1 are placed, so "<obj> image 1", "<obj> image 2", "<obj> text 1 Is described, and a description indicating the attribute of the content is performed under each description.

  As a description of the image 1, description is performed using <filename>, <size>, <offset>, <reso>, and <color> tags after the <obj> tag.

  The <filename> tag is for describing a file type by a file name and an identifier. Here, since the file name of the image 1 is “img1.tif”, description by a tag <filename> img1.tif </ filename> is performed. This description makes it clear that the file name is “img1” and the file type is the TIFF file from the identifier “.tif”. Therefore, in the rasterizing process described later, the process is executed with reference to this description.

  Here, the <size> tag describes the layout size of the page data PD of the image 1. The size specified by the <size> tag can be set in a predetermined unit such as mm or pixels.

  The <offset> tag is a tag for describing the offset position of the image 1. Here, since it is described as <offset> O1 </ offset>, image 1 is arranged so that the offset position “O1” from the origin O of the A4 area indicated by the page data PD is the lower left point of image 1. Which indicates that. The offset position O1 is defined by the XY coordinate system description, but may be a polar coordinate system description.

  The <reso> tag is a tag for describing the image resolution of the image 1. Here, since it is described as <reso> 300 dpi </ reso>, it indicates that the image 1 has a resolution of “300 dpi (dot per inch)”. The resolution defined by the <reso> tag can be set in predetermined units such as lpi (line per inch) and ppm (pixel per meter) in addition to dpi.

  The <color> tag is a description for indicating the color of the image 1. Here, since it is described as <color> mono </ color>, it indicates that image 1 is “monochrome”. In addition, since the identifier of the <fimename> tag is “tif”, it can be seen that image 1 is a TIFF file, and it is clear from these two tags that image 1 is binary image data that is a 1-bit TIFF file. .

  The <color> tag uses “full (CMYK)”, “CM (C, M ink only)”, “C, M, Y, K, Sp (Sp is a special color)”, etc. The number and type of ink can be described.

  After image 1 is described, image 2 is described as <obj> image 2. The description of the image 2 is almost the same as the description of the image 1, but the description of the <filename> tag and the <color> tag is different from that of the image 1.

  Since the <filename> tag of the image 2 is <filename> img2.jpg </ filename>, the identifier is “jpg” and it is described that the image data 2 is IPEG data. Also, since the <color> tag is <color> full </ color>, it becomes clear that the image 2 is multi-value image data that is CT image data printed in CMYK.

  After image 1 and image 2, text 1 is described as <obj> text 1. The description of text 1 is almost the same as the description of images 1 and 2, but the <font> tag is present and the <reso> tag is not present, unlike the descriptions of images 1 and 2.

  The <font> tag is a description for indicating a typeface expressing the text 1. Here, since the <font> tag is <font> mincho </ font>, it indicates that the typeface of text 1 is “Mincho”.

  On the other hand, since the text 1 has no <reso> tag, the typeface representing the text 1 is drawn depending on the resolution of the text 1 depending on the output resolution set in the rasterizing condition.

  FIG. 3 is a flowchart for explaining the operation of the rasterization processing apparatus 1. For the page data PD shown in FIG. 2, the CPU 11 of the rasterization processing apparatus 1 develops the program P in the memory 17, performs the operation shown in this flowchart, and executes the rasterization process.

  In step S1, the rasterization condition setting unit 171 sets rasterization conditions based on the input from the input unit 13 by the operator of the rasterization processing apparatus 1. The rasterization conditions that are set include the output resolution, color settings, and network type of the rasterization conditions. In particular, the setting of “output resolution” is used in a process that will be described later.

  Here, as the rasterization condition set by the rasterization condition setting unit 171, the output resolution is “600 dpi”.

  In step S2, the page data analysis unit 172 of the rasterization processing device 1 analyzes the page data PD input to the rasterization processing device 1. When the page data PD is input to the rasterization processing device 1 via the network I / F 14 or the media drive 15 that has read the media disk 18, the page data analysis unit 172 is based on the description of the page data PD. In addition to analyzing the analysis of the page data PD, it determines whether or not there is an error in the page data PD, and identifies the content used in the page data PD. In this case, the contents used in the page data PD are “Image 1 (img1.tif)”, “Image 2 (img2.jpg)”, “Text 1 (txt1.txt)” as shown in FIG. And

  If the contents are identified as a result of the analysis of the page data PD in step S2, the process proceeds to step S3 for determining whether or not image conversion has been completed for all contents.

  The rasterization processing device 1 compares the number of contents temporarily stored in the rasterization processing unit 175 with the number of contents included in the page data PD to determine whether or not the image conversion for the contents has been completed. Determine. If the result of determination in step S3 is that image conversion has been completed for all identified content, the process proceeds to step S8, and if there is content that has not undergone image conversion, the process proceeds to step S4.

  In step S4, for content that has not undergone image conversion, the image data resolution acquisition unit 1721 refers to the description of the page data PD to acquire the resolution of the image data that is the content.

  The rasterization processing apparatus 1 acquires the image resolution for content that has not been subjected to image conversion in accordance with the description of the page data PD. In the content, since the image resolution is described by the <reso> tag, the image data resolution acquisition unit 1721 refers to the <reso> tag and acquires the image resolution.

  When the image resolution is not described by the <reso> tag, the image data resolution acquisition unit 1721 may acquire the resolution embedded in the image data as the image resolution.

  In step S5, the output resolution-image resolution comparison unit 173 compares the output resolution of the rasterization condition set by the rasterization condition setting unit 171 with the image output resolution acquired by the image data resolution acquisition unit 1721. If “output resolution> image resolution”, the process proceeds to step S6.

  If the output resolution of the rasterization condition is higher than the image resolution as a result of comparison between the output resolution of the rasterization condition and the image resolution, performing rasterization processing on the image data will cause various types of moiré and graining. Image defects can occur. In order to prevent image defects due to such rasterization processing, the determination in step S5 is performed. If “output resolution of rasterization condition> image resolution”, the process proceeds to step S6 for performing image conversion described later.

  On the other hand, as a result of comparison, if the output resolution of the rasterization condition ≦ image resolution or the content is text data and the image data resolution acquisition unit 1721 cannot acquire the image resolution, the image defect is unlikely to occur. No special image conversion is performed, and the rasterization processing apparatus 1 sends the content as converted image data to the rasterization processing unit 175, and returns to step S3.

  In step S6, the image data conversion unit 174 matches the image resolution of the content with the output resolution of the rasterization condition, and performs image data conversion processing. The image data conversion unit 174 suppresses image defects caused by the difference in resolution by matching the image resolution with the output resolution of the rasterization condition for content that may cause an image defect, and the image resolution is changed to the output resolution of the rasterization condition. The image processing for removing the defect caused by matching is performed, and the image data conversion processing is executed. Details will be described later.

  If the image conversion in step S6 has been performed, the rasterization processing apparatus 1 sends the content as converted image data to the rasterization processing unit 175, and returns to step S3.

  When the processes of steps S3 to S6 are repeated and it is determined that the image conversion has been completed for all the contents included in the page data PD, the process proceeds to step S7, and the rasterization processing unit 175 performs the rasterization process of the page data PD.

  The rasterization processing unit 175 draws rasterized data with reference to the description of the page data PD based on the rasterization condition set by the rasterization condition setting unit 171 and temporarily refers to the offset position described in the page data PD. By placing the stored converted image data in the rendered rasterized data, the page data PD described in the program is converted into rasterized data RD representing a printed matter.

  After the conversion of the page data PD, the rasterization processing device 1 writes the rasterized data RD to the media disk 18 via the network I / F 14 or the media drive 15 and outputs it. The output rasterized data RD is used for printing processing in a printing apparatus (not shown) or plate making processing in CTP. Further, the rasterized data RD may be temporarily stored in the storage unit 16.

  To describe the details of the image conversion in step S6, refer to FIG. FIG. 4 is a flowchart for explaining the operation of the image data converter 174.

  In step S61 in the flowchart of FIG. 4, the image data conversion unit 174 sets image conversion. The image data conversion unit 174 displays a condition setting menu JS for setting image conversion conditions on the display unit 12. The operator of the rasterizing apparatus 1 performs condition setting by inputting the condition setting menu JS with the input unit 13.

  FIG. 5 shows a condition setting menu JS displayed on the display unit 12 by the image data conversion unit 174. The condition setting menu JS includes an image defect input field JS1, a condition setting field JS2, a filter processing setting field JS3, an OK button JS4, and a cancel button JS5.

  The image defect input field JS1 is a field for inputting the purpose of conversion by the image data conversion unit 174. As a result of rasterization processing, image data conversion unit 174 performs image conversion in order to suppress the occurrence of moire or graininess in image data, so that the image defect name that is the purpose of image conversion is rasterized. The operator of the device 1 operates the input unit 13 for input.

  The condition setting field JS2 is a field for setting conditions for image conversion. Each item is provided with a check box CB, and a plurality of conditions can be selected. For example, when it is desired to perform image conversion when the image resolution of a 1-bit TIFF image is lower than the rasterized output resolution, the operator checks the check boxes of “1 bit TIFF” and “Output resolution> Image resolution” in the condition setting field JS2. As a result, the image data conversion unit 174 performs image conversion on image data that is a 1-bit TIFF file and that has output resolution> image resolution of rasterization conditions.

  The filter processing setting column JS3 is a column for setting filter processing performed as image conversion. Each item is provided with a radio button RB, and conditions can be selected exclusively. For example, when “super sampling” is desired as the filter processing, the operator checks the “super sampling” radio button in the filter processing setting field JS3 to obtain the image data corresponding to the condition set in the condition setting field JS2. On the other hand, supersampling is performed.

  The OK button JS4 is a button that is pressed when the operator is satisfied with the input to the condition setting menu JS. When the operator presses the OK button JS4, the image data conversion unit 174 displays the defect name input in the image defect name input field JS1, the condition setting and filter processing setting set in the condition setting field JS2 and the filter processing setting field JS3. Are stored in association with each other.

  The cancel button JS5 is a button that is pressed when the operator interrupts input to the condition setting menu JS.

  Note that step S61 may be performed after setting rasterization conditions after step S1 in FIG.

  If the image conversion condition setting is completed in step S61, the process proceeds to step S62. In step S62, the image data conversion unit 174 determines whether the image data to be converted is 1-bit TIFF data.

  In step S61, when “1bitTIFF” is specified in the condition setting JS2, referring to the description of the page data PD, the <filename> identifier of the content subject to image conversion is “.tif”. If <color> is “monochrome”, the image data conversion unit 174 proceeds to step S63 with the content as 1-bit TIFF data of a binary image.

  If it is determined that the image data is not 1-bit TIFF data but multi-value image data, the process proceeds to step S64c. In step S64c, the image data conversion unit 174 performs resolution conversion to match the image resolution with the output resolution of the rasterization condition for the multivalued image data in which “output resolution of rasterization condition> image resolution”.

  The resolution conversion performed in S64c is a resolution conversion that matches the output resolution of the rasterization conditions, such as a bicubic method and a super-resolution process, and involves a high-definition process for multi-valued image data. After the resolution conversion is completed, filter processing is executed on the image data in step S65c. When the filter processing is specified in the filter processing setting field JS3, the multi-value image conversion unit 1742 of the image data conversion unit 174 performs the filter processing on the image data. If not specified, the default filter processing ( For example, blur processing is performed.

  If the processing of S65c is completed, in step S68, the image data processed by the image data conversion unit 174 is sent to the rasterization processing unit 175 as converted image data.

  If it is determined in S62 that the image data is “1bit TIFF data”, the image data converter 174 determines whether or not supersampling is set in the filter processing setting field JS3 for the condition setting menu JS in step S61. Judge with. If supersampling is set, the process proceeds to step S64a, and if not set, the process proceeds to step S64b.

  The resolution conversion performed in step S64b matches the image resolution of the image data with the rasterized output resolution by a predetermined resolution conversion such as a bilinear method or a bicubic method. After the resolution conversion is completed, filter processing is executed on the image data in step S65b. When the filter processing is specified in the filter processing setting field JS3, the binary image conversion unit 1741 of the image data conversion unit 174 performs the filter processing on the image data. If not specified, the default filter processing ( For example, blur processing is performed.

  If the processing of S65b is completed, in step S68, the image data processed by the image data conversion unit 174 is sent to the rasterization processing unit 175 as converted image data.

  If it is determined in step S62 that super-sampling is performed on the 1-bit TIFF data, the process proceeds to step S64a, and the image data conversion unit 174 converts the image resolution of the 1-bit TIFF data to a rasterized output resolution or higher. When converting the image resolution of the 1-bit TIFF data to a rasterized output resolution or higher, the image data converter 174 converts the resolution to, for example, a resolution that is at least twice the rasterized output resolution. After the process of step S64a is completed, the image data conversion unit 174 performs conversion processing of the image data that has undergone resolution conversion by the binary image conversion unit 1741.

  In step S65a, the binary image conversion unit 1741 performs anti-aliasing processing on the image data that has undergone resolution conversion. When digital processing is performed on 1-bit TIFF data that is a binary image, jagged edges called jaggy are generated in the outline of the 1-bit TIFF image. In order to reduce this jaggy and make it less noticeable, it is an anti-aliasing process that smoothly changes the color so that the outline of the image is fused with the background.

  After the anti-aliasing processing by the binary image conversion unit 1741 in S65a, the image data conversion unit 174 performs resolution conversion so that the image resolution of the anti-aliased image data matches the rasterized output resolution.

  The image data subjected to the anti-aliasing processing is subjected to pixel interpolation using intermediate colors in order to reduce jaggies. However, since the image data to be subjected to this image conversion is a 1-bit TIFF binary image, it is not possible to output image data that has undergone anti-aliasing processing. Therefore, the image data conversion unit 174 reduces the image resolution of the high-resolution image data so as to match the output resolution of the rasterization condition, thereby generating a resolution image that averages the pixels of the high-resolution image. Therefore, it is possible to obtain a higher quality image than the resolution conversion that simply matches the image resolution of the image data with the output resolution of the rasterization condition.

  In step S67a, when the filter processing is specified in the filter processing setting field JS3, the binary image converting unit 1741 performs the filter processing on the image data. If not specified, the default filter processing (for example, blur) Process).

  When the output destination of the image data is an output device capable of outputting multi-value image data, the multi-value image data subjected to anti-aliasing processing is output without performing the filter processing by the binary image conversion unit 1741. It may be.

  When the processing of S67a is completed, in step S68, the image data processed by the image data conversion unit 174 is sent to the rasterization processing unit 175 as converted image data.

  FIG. 6 is a diagram for explaining a state in which the rasterization processing apparatus 1 has converted the page data PD shown in FIG. 2 into rasterized data RD by an operation based on the flowcharts of FIGS.

  In the page data PD of FIG. 2, image 1 (img1.tif), image 2 (img2.jpg), and text 1 (txt1.txt) are stored. The rasterization processing apparatus 1 is a binary image that is a 1-bit TIFF file and <reso> is “300 dpi” because the identifier in <filename> is “tif” and <color> is “mono” for image 1. Therefore, it is determined that the image resolution is lower than the output resolution of the rasterization condition, and the image conversion unit 174 determines whether to perform image conversion with supersampling based on the determination in step S62. Transition. If “super sampling” is set in the filter condition setting field JS3, the process proceeds to step S64a, and the rasterizing apparatus 1 performs image conversion with super sampling on img1.tif.

  In the rasterizing apparatus 1, the identifier in <filename> for the image 2 is “jpg”. Since <color> is “full”, it is a multi-value image that is CT image data, and <reso> is 350 dpi, so image conversion by the image conversion unit 174 is performed.

  The rasterization processing apparatus 1 does not make the image conversion target by the image conversion unit 174 because the identifier in <filename> is “txt” for the text 1.

  The contents of the page data PD are sent to the rasterization processing unit 175, and are arranged in the rasterized data RD that has been subjected to rasterization processing based on the description of the page data PD.

  As shown in the figure, when the output resolution in rasterization processing is 600dpi, rasterized data RD is created in which 600dpi image 1, 600dpi image 2, 600dpi text 1 is placed on a 600dpi A4 page . Here, with respect to the images 1 and 2, as a result of the conversion processing performed by the image data conversion unit 174, filter processing is performed so that the image resolution matches the output resolution of the rasterization condition and image defects do not occur. ing.

  Therefore, the rasterization processing apparatus 1 can perform appropriate printing without degrading the image quality even if the output resolution of the printing press at the time of printing is not unified.

<Modification>
In the description so far, the rasterization processing apparatus 1 has been described as one apparatus, but a plurality of computers may jointly exert the same action.

  In the description so far, the page data PD has been input from the outside of the rasterization processing device 1, but the rasterization processing device 1 may include the page data creation unit (not shown) to create the page data PD.

1 Rasterization processing device
11 CPU
12 Display section
13 Input section
14 Network I / F
15 Media drive
16 Memory
17 memory
18 Media disc
171 Rasterization condition setting section
172 Page Data Analysis Department
173 Output resolution-Image resolution comparison section
174 Image data converter
175 Rasterization processing section
1721 Image data resolution acquisition unit
1741 Binary image converter
1742 Multilevel image converter
JS condition setting menu
JS1 Image defect input field
JS2 condition setting field
JS3 filter processing setting field
PD page data
RD rasterized data

Claims (11)

A rasterization processing device that outputs rasterized data that can be output by a recording device from page data described in a page description language,
Rasterization condition setting means for setting at least the output resolution of the rasterized data as rasterization conditions for outputting the rasterized data;
Analyzing the page data and identifying page data analyzing means for identifying content data included in the page data;
Image data resolution acquisition means for acquiring an image resolution representing the image from image data for displaying an image among the content data identified from the page data;
Resolution comparison means for comparing the output resolution of the rasterization condition and the image resolution of the image data;
As a result of the comparison by the resolution comparison means, if the image resolution of the image data is lower than the output resolution of the rasterization condition, an image type acquisition means for acquiring the image type of the image data;
Image data conversion means for performing image processing based on the image type and processing for matching the image resolution to the output resolution for the image data;
Rasterization output means for performing rasterization processing based on the page data including the image data converted by the image data conversion means according to the rasterization conditions, and outputting the rasterized data;
A rasterization processing apparatus comprising: The rasterization processing device according to claim 1, wherein
The image processing performed by the image data converting means is processing for removing image defects caused when the image data is rasterized.
A rasterizing apparatus characterized by the above. The rasterization processing device according to claim 1 or 2,
The image data conversion means, image processing condition setting means for setting image processing conditions related to the image processing;
A rasterization processing apparatus comprising: The rasterization processing device according to any one of claims 1 to 3,
When the image type of the image data is a binary image, the image data conversion means performs a moire reduction process as an image process;
A rasterizing apparatus characterized by the above. The rasterization processing device according to any one of claims 1 to 3,
When the image type of the image data is a multi-valued image, the image data conversion means performs high definition processing as image processing;
A rasterizing apparatus characterized by the above. A rasterization processing method for outputting rasterized data that can be output by a recording device from page data described in a page description language,
Rasterization condition setting step for setting at least the output resolution of the rasterized data as rasterization conditions for outputting the rasterized data;
A page data analysis step of analyzing the page data and identifying content data included in the page data;
An image data resolution acquisition step of acquiring an image resolution representing the image from image data for displaying an image among the content data identified from the page data;
A resolution comparison step of comparing the output resolution of the rasterization condition and the image resolution of the image data;
As a result of the comparison by the resolution comparison step, when the image resolution of the image data is lower than the output resolution of the rasterization condition, an image data type acquisition step of acquiring the image type of the image data;
An image data conversion step for performing image processing based on the image type and processing for matching the image resolution to the output resolution for the image data;
Rasterization output step of performing rasterization processing based on the page data including the image data converted in the image data conversion step according to the rasterization condition, and outputting the rasterized data;
A rasterization processing method comprising: Rasterization processing for outputting rasterized data that can be output by a recording device from page data described in a page description language when the CPU of the computer executes in a memory in a computer having a display unit and an operation unit A program for realizing as a device,
A rasterizing condition setting step for setting at least an output resolution of the rasterized data as a rasterizing condition for outputting the rasterized data;
A page data analysis step of analyzing the page data and identifying content data included in the page data;
An image data resolution acquisition step of acquiring an image resolution representing the image from image data for displaying an image among the content data identified from the page data;
A resolution comparison step of comparing the output resolution of the rasterization condition and the image resolution of the image data;
As a result of the comparison in the resolution comparison step, when the image resolution of the image data is lower than the output resolution of the rasterization condition, an image data type acquisition step of acquiring the image type of the image data;
An image data conversion step for performing image processing based on the image type and processing for matching the image resolution to the output resolution for the image data;
Rasterization output step of performing rasterization processing based on the page data including the image data converted by the image data conversion means according to the rasterization conditions, and outputting the rasterized data;
A program comprising The program according to claim 7, wherein
The image processing performed by the image data conversion step is processing for removing image defects that occur when the image data is rasterized.
A program characterized by A program according to any one of claims 7 to 8,
The image data conversion step is an image processing condition setting step for setting an image processing condition related to the image processing;
A program comprising: The program according to any one of claims 7 to 9,
When the image type of the image data is a binary image, the image data conversion step performs moiré reduction processing as image processing;
A program characterized by The program according to any one of claims 7 to 9,
When the image type of the image data is a multi-valued image, the image data conversion means performs high definition processing as image processing;
A program characterized by

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