JP2009169727A - Image processing apparatus, image processing method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a print of high quality by storing shapes of very small pixels in one pixel as fine pixels by pixels for a part, such as characters, requiring high image quality when an image is generated, adding color information on the fine pixels, developing the fine pixels during image processing, and performing resolution conversion. <P>SOLUTION: An image processing apparatus includes a high-resolution graphics data generating means of generating graphics data of high resolution, a low-resolution color information drawing means of reading in the data generated by the means and drawing low-resolution color information; an RGB band memory area 114c which stores the image generated by the drawing means; a high-definition shape drawing means of reading in the data generated by the high-resolution graphics data generating means and generating fine pixel shape information of high resolution, a fine pixel band memory area 114d which stores the fine pixel shape information generated by the drawing means; and a high-resolution converting means of performing conversion to high resolution, by using the color information and fine pixel shape information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  Conventionally, jerky correction is generally performed in laser printers, digital copiers, and the like for correcting and smoothing stepped portions of characters and image outlines when printing bitmap image data. .

  An image data processing apparatus is disclosed that performs correction for reducing toner consumption in addition to performing jaggy correction for smoothing the staircase portions of characters and figures (see, for example, Patent Document 1). ). This apparatus arranges image data in the form of a bitmap, generates a pixel matrix (image data distribution) of a predetermined size centering on a correction target pixel (image data), and this is called a window. Extracting features of the content distribution of the data and generating code representing it, and displaying the features as a high-quality image from the pattern memory and storing image data stored in advance in order to reduce toner consumption ( Data after correction) is read in correspondence with the generated code, written to the output buffer memory, and then output to the printer engine (image forming mechanism and mechanism controller). In order to realize this, an input buffer memory for arranging the image data into a window array, a feature of the content distribution of the image data of the window is extracted, a pattern recognition and a code for generating a code representing the extracted feature A memory block group storing image data representing a high-definition image and a low toner consumption image, and an output buffer memory.

  Conventionally, an anti-aliasing method is known as a computer graphics technique. In addition to the frame memory, it has a device that stores pixel information corresponding to each pixel, determines whether each pixel is a side, and if it is a side, stores the area of the pixel and the direction of the side of the pixel An anti-aliasing method is known that calculates an accurate color by calculating with surrounding pixels at the time of video output (see, for example, Patent Document 2).

  In addition to RGB color information for each pixel, there is also known a method of adding attribute information (character or not, edge flag, edge boundary, etc.) and performing image processing using such information. (For example, see Patent Document 3).

Japanese Patent Laid-Open No. 9-168086 Japanese Patent No. 3609189 JP 2000-134468 A

  However, in Patent Document 1 as shown above, a method for obtaining and interpolating the inclination of a pixel from information around the pixel to be obtained is used. Is difficult to correct with high accuracy. Similarly, even in Patent Document 3, the edge information of characters is used to aim for high image quality by image processing, but it is not possible to correct a high resolution one with a low resolution from a low original one. difficult.

  The present invention has been made in view of the above, and in a portion where high image quality such as characters is required at the time of image generation, the shape of a minute pixel inside one pixel is stored in each pixel unit as a minute pixel. An object of the present invention is to enable high-resolution printing by adding color information of minute pixels, expanding minute pixels during image processing, and converting the resolution.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 is a high-resolution graphics data generation unit that analyzes input information and generates high-resolution graphics data, and the high-resolution graphics. A low-resolution color information drawing unit that reads data generated by the data generation unit and draws low-resolution color information; and a low-resolution color information storage unit that stores an image generated by the low-resolution color information drawing unit; , Reading the data generated by the high-resolution graphics data generating means, and generating high-definition shape drawing means for generating high-resolution minute pixel shape information, and storing the minute pixel shape information generated by the high-definition shape drawing means The minute pixel shape storage means, the color information stored in the low resolution color information storage means, and the minute pixel shape storage means. High resolution conversion means for converting into 憶 been micropixel shape information by high resolution, characterized in that it comprises a.

  The invention according to claim 2 reads the color information stored in the low-resolution color information storage means, determines that the color is the same as the color of high-definition shape drawing or a white background, and The micropixel shape information to be newly drawn is ORed to the micropixel shape information stored in the shape storage means, and is again stored in the micropixel shape storage means.

  The invention according to claim 3 reads the color information stored in the low-resolution color information storage means, determines that the color is not the same as the color for drawing a high-definition shape, or is not a white background, and the minute pixel shape The micropixel shape information is not changed in the storage means.

  According to a fourth aspect of the present invention, there is provided a high-resolution conversion means for reading the color information stored in the color information storage means and the minute pixel shape information stored in the minute pixel shape storage means for each line and performing resolution conversion. It is characterized by having.

  According to a fifth aspect of the present invention, there is provided an image processing method executed by an image processing apparatus, wherein the image processing apparatus includes a low-resolution color information storage unit and a minute pixel shape storage unit. Data generated in the high-resolution graphics data generation step by the high-resolution graphics data generation step by which the input information is analyzed by the graphics data generation unit and high-resolution graphics data is generated, and the low-resolution color information drawing unit. The low-resolution color information drawing step for drawing low-resolution color information and storing the low-resolution color information in the low-resolution color information storage unit; and the data generated by the high-resolution graphics data generation unit by the high-definition shape drawing unit. A fine shape drawing step for reading, generating high-resolution micropixel shape information, and storing the micropixel shape storage means; Color information stored in the low-resolution color information storage means by the resolution conversion means, and a high-resolution conversion step for converting to high resolution using the minute pixel shape information stored in the minute pixel shape storage means. Features.

  The invention according to claim 6 is a program for causing a computer to execute the image processing method according to claim 5.

  The invention according to the present invention stores the shape of a minute pixel inside one pixel as a minute pixel in a portion that requires high image quality, such as characters, at the time of image generation by the image forming apparatus. By adding information and developing the minute pixels during image processing and converting the resolution, there is an effect that printing with high resolution becomes possible.

  Exemplary embodiments of an image processing apparatus, an image processing method, and a program according to the present invention are explained in detail below with reference to the accompanying drawings.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a mechanism unit of a multicolor image forming apparatus embodying the present invention. In this multicolor image forming apparatus, reference numeral 1 denotes a belt-like photoconductor as an image carrier, and the photoconductor 1 is rotatably supported by rotating rollers 2 and 3. It is rotated in the direction of arrow A by driving. On the outer periphery of the photoreceptor 1, a charging device 4 as a charging unit 4, a static elimination lamp L, and a cleaning blade 15 </ b> A for the photoreceptor 1 are arranged. At the downstream position of the charging device 4, there is an optical writing unit that is irradiated with laser light emitted from a laser writing unit 5 that is optical writing means.

  A multi-color developing device 6 in which a plurality of developing units (developing means) are supported in a switchable manner is disposed downstream of the optical writing unit. The multicolor developing device 6 includes a yellow developing unit, a magenta developing unit, and a cyan developing unit for each color of toner to be accommodated. A black developing unit 7 containing black toner is provided at the top of the multicolor developing device 6.

  Any one of these development units moves to a developable position in synchronization with the development timing of the corresponding color. The multicolor developing device 6 has a function of selecting any developing unit by rotating 120 degrees on the circumference. When these developing units operate, the black developing unit 7 moves to a position separated from the photoreceptor 1. The movement is performed by the rotation of the cam 45.

  The laser writing unit 5 sequentially generates laser light according to image forming signals (writing information) of a plurality of colors from a laser light source (not shown), and periodically uses the polygon mirror 5B rotated by the polygon motor 5A. Then, the surface of the charged photoreceptor 1 is scanned through the fθ lens 5C and the mirror 5D, and an electrostatic latent image is formed on the surface.

  The electrostatic latent image formed on the surface of the photoreceptor 1 is developed with toner from the corresponding developing unit, and a toner image is formed and held. The intermediate transfer belt 10 is adjacent to the photoreceptor 1 and is supported by rotating rollers 11 and 12 so as to be rotatable in the direction indicated by the arrow B. The toner image on the photoreceptor 1 is transferred onto the surface of the intermediate transfer belt 10 by a transfer brush (first transfer means) 13 on the back side of the intermediate transfer belt 10.

  The surface of the photoreceptor 1 is cleaned for each color by the cleaning blade 15A, and a toner image of a predetermined color is formed on the surface. Each time the intermediate transfer belt 10 is rotated, the toner image on the photosensitive member 1 is transferred to the same position on the surface, and a plurality of color toner images are superimposed and held on the intermediate transfer belt 10. The Thereafter, the toner image is transferred to a recording medium such as paper or plastic.

  At the time of transfer onto the paper, the paper stored in the paper feeding device (paper feeding cassette) 17 is fed out by the paper feeding roller 18 and transported by the transporting roller 19, and is temporarily applied to the registration roller pair 20. After being stopped, the toner image is transferred to the nip between the intermediate transfer belt 10 and the transfer roller (second transfer means) 14 at a timing so that the transfer position of the toner image becomes normal. Then, after the toner images of a plurality of colors on the intermediate transfer belt 10 are collectively transferred by the action of the transfer roller 14, the sheet is sent to the fixing device 50, where the toner image is fixed, and then the paper discharge roller pair 51. As a result, the paper is discharged to the paper discharge stack 52 at the top of the main body frame 9.

  The intermediate transfer belt 10 is provided with a cleaning device 16 for the intermediate transfer belt 10 at a portion of the rotation roller 11 so that the cleaning blade 16A can be contacted and separated via a cleaning blade contacting / separating arm 16C. In the process of receiving the toner image from the photoreceptor 1, the cleaning blade 16A is separated from the intermediate transfer belt 10 and comes into contact after the toner image is transferred from the intermediate transfer belt 10 to the paper. The residual toner after the toner is transferred is scraped off. As already described, there are cleaning blades for the photoreceptor 1 and the intermediate transfer belt 10. Waste toner scraped by these blades is stored in a collection container 15. The collection container 15 is replaced as appropriate. An auger 16B provided inside the cleaning device 16 for the intermediate transfer belt 10 conveys waste toner scraped off by the cleaning blade 16A and sends it to the collection container 15 by a conveying means (not shown).

  Reference numeral 31 denotes a unitized process cartridge, which includes a photosensitive member 1, a charging device 4, an intermediate transfer belt 10, a cleaning device 16, a transport guide 30 that forms a paper transport path, and the like so that they can be replaced when the end of their service life is reached. It is configured. In addition to the replacement of the process cartridge 31, the multi-color developing device 6, the black developing unit 7 and the like are also replaced at the end of their service life. However, in order to facilitate the exchange and handling of jammed paper, Has a structure that can be opened and closed about the support shaft 9A.

  On the left side of FIG. 1, an electrical / control device 60 is housed. Above that, a fan 58 is provided, which exhausts air to prevent the temperature inside the machine from rising excessively. On the right side of the figure, another relatively small paper feeder 59 is provided. In this embodiment, the intermediate transfer belt 10 is used as an intermediate transfer member, but an intermediate transfer drum can also be used.

  Next, a detailed configuration and operation of the image processing apparatus in the color printer configured as described above will be described. FIG. 2 is a block diagram showing the configuration of the electrical / control apparatus in FIG. Reference numeral 101 denotes a CPU which controls the entire printer apparatus and analyzes PDL sent from a PC (personal computer) to generate drawing commands for the drawing apparatus 105 and parameters of the image processing apparatus. Reference numeral 102 denotes a CPU I / F, which is an interface of the CPU 101 and is connected to a memory and various controllers via a memory arbiter 103. Reference numeral 103 denotes a memory arbiter that arbitrates between the main memory 114 and various controllers. Reference numeral 104 denotes a memory controller which controls the main memory 114 and is connected to various controllers and CPUs via the memory arbiter 103. Reference numeral 105 denotes a drawing apparatus described later.

  Reference numeral 106 denotes a bus controller, which performs bus arbitration with each peripheral controller connected to the bus 11. Reference numeral 107 denotes a communication controller, which is connected to a network, receives various data and commands from the network, and is connected to various controllers via the memory arbiter 103. Reference numeral 113 denotes a ROM which stores various programs and font information such as characters. Reference numeral 114 denotes a main memory which stores image data, the encoded data, a program of the CPU 011 and the like. Reference numeral 115 denotes a memory controller built-in CPU, which incorporates a CPU 101, a memory controller 105, and the like.

  Reference numeral 116 denotes a bus, which connects the CPU 115 with built-in memory controller, the image processing ASIC 117, and the panel control ASIC 118. Reference numeral 117 denotes an image processing ASIC, which is connected to the memory controller built-in CPU 115 and performs image processing. Reference numeral 118 denotes a panel control ASIC, which is connected to the CPU 101 and controls the panel. Reference numeral 121 denotes a printer controller board that controls the printer. Reference numeral 120 denotes a PC, which creates a PDL (Page Description Language) for the printer and transfers it to the printer via the network. Reference numeral 122 denotes a printer engine. Reference numeral 108 denotes a bus I / F, which performs an I / F of the bus 116 and is connected to the CPU 115 with a built-in memory controller. Reference numeral 109 denotes an engine controller that controls the printer engine 122.

  Reference numeral 110 denotes an image processing apparatus, which reads an image processing parameter generated by the CPU 101, performs image processing, and writes it to a designated position of image data in the main memory 114. Reference numeral 111 denotes a bus I / F, which transfers data of the panel controller 112 to the CPU 115 with a built-in memory controller. Reference numeral 112 denotes a panel controller that controls the panel 119. Reference numeral 119 denotes a panel for notifying the printer apparatus of an operation from the user.

  FIG. 3 is a block diagram showing a flow of image processing according to the embodiment of the present invention. In FIG. 3, the CPU 101 analyzes the PDL stored in the PDL memory area 114 a of the main memory 114. The CPU 101 generates character graphics data and stores it in the character graphics data memory area 114 b of the main memory 114. The drawing device 105 reads character graphics data in the main memory 114 and draws RGB band data and minute pixel band data. The generated RGB band data is stored in the RGB band memory area 114c of the main memory 114, and the minute pixel band data is stored in the minute pixel band memory area 114d of the main memory 114. Further, the CPU 101 generates image processing parameters for the image processing apparatus 110. The main memory 114 stores the image processing parameters generated by the CPU 101 in the image processing parameter memory area 114e. The image processing apparatus 110 receives the image processing parameters stored in the main memory 114, reads the RGB band data from the RGB band memory area 113c of the main memory 114, and reads the minute pixel band from the minute pixel band memory area 114d of the main memory 114. Read and perform gradation processing. Then, it is transferred to the page memory area 114f after gradation processing in the main memory 114, and the main memory 114 stores it in the page memory area 114f after gradation processing. Thereafter, the printer engine 122 prints out according to the page data after gradation processing.

  FIG. 4 is a block diagram showing the concept of image processing according to the embodiment of the present invention. In FIG. 4, the PC 120 generates PDL (page description language) and transfers it to the printer via the network. The communication network 107 receives the PDL from the PC 120 and stores it in the PDL memory area 114 a of the main memory 114. The main memory 114 stores PDL, image processing parameters, character graphics data, RGB multilevel band data, minute pixel band data, post-gradation page data, programs, various work data, and the like. The CPU 101 analyzes the PDL from the PC 120, generates image processing parameters of the image processing apparatus 110 and character graphics data of the drawing apparatus 105, and writes them into the main memory 114. The drawing device 105 reads the graphics data for characters in the main memory 114, and draws the RGB band and draws the minute pixel RGB band and the minute pixel band. The image processing apparatus 110 reads image processing parameters from the image processing parameter area of the main memory 114, reads the RGB band drawing and the minute pixel band of the main memory 114, performs image processing, and draws the page after gradation processing. The engine controller 109 reads the page image after gradation processing from the main memory 114 and transfers it to the printer engine 122. The printer engine 122 forms a page image after gradation processing sent from the engine controller 109 on recording paper.

  FIG. 5 shows a format example of the main memory 114. FIG. 6 shows an example of character graphics data. In this way, it is a collection of horizontal scan information of the Y coordinate (Y), the X start point coordinate (XS), and the X end point coordinate (XE) at high resolution. FIG. 7 shows a memory format of character graphics data in the main memory 114. FIG. 8 shows the RGB band image memory format of the main memory 114. FIG. 9 shows a minute pixel band memory format of the main memory 114. Here, the shape in one pixel of the RGB band is shown. In this example, shape information having twice the resolution is stored.

  FIG. 10 shows a drawing example of 1200 DPI characters. Thus, high definition is required for characters. FIG. 11 shows an example of RGB band image data. In this example, RGB band images are stored at 600 DPI. FIG. 12 shows an example of a minute pixel band image. In this way, the minute pixels in the 600 DPI unit are expressed by the DOT image information of FIG. For this reason, the resolution of the image is expanded and an expression equivalent to 1200 DPI is possible. As described above, the minute pixel band image can express the color only in units of 600 DPI, but can express the shape of 1200 DPI. FIG. 13 shows an example in which actual characters are printed. A character image that is basically 600 DPI but has been processed with a minute pixel is an image similar to 1200 DPI.

  FIG. 14 is a flowchart showing the operation processing of the entire image processing according to the embodiment of the present invention. First, the CPU 101 analyzes the PDL, generates an image processing parameter of the image processing apparatus 110, and stores it in the image processing parameter memory area 114e of the main memory 114 (step S1). Subsequently, the image processing apparatus 110 reads image processing parameters from the image processing parameter memory area 114e of the main memory 114 (step S2). The CPU 101 analyzes the PDL and generates 1200 DPI character graphics data (step S3). The drawing device 105 reads the graphics data for characters and draws the RGB data in the RGB band memory area 114c. At this time, when rendering with high accuracy such as a character image, the minute pixels are written into the minute pixel band memory area 114d (step S4). The processes in steps S3 and S4 are repeated until one band is completed (until the determination in step S5 is YES). When the processing for one band is completed, the image processing apparatus 110 reads an RGB image from the RGB band memory area 114c of the main memory 114, reads a minute pixel from the minute pixel band memory area, performs image processing, and performs an image processing result. Is transferred to the page memory area 114f after gradation processing in the main memory 114 (step S6). The process in step S6 is repeatedly executed until one band is completed (until the determination in step S7 is YES). As described above, the processes in steps S3 to S7 are executed until the process for one band is completed (step S8).

  FIG. 15 shows a conceptual diagram of the character drawing process. In this way, high-resolution (1200 DPI) character graphics data (scan line data) is read, and a low-resolution (600 DPI) RGB band image is drawn and high-resolution (1200 DPI) minute pixel information in units of low resolution (600 DPI). Draw.

  16 to 18 are flowcharts showing the processing operation of the character drawing process according to the embodiment of the present invention. First, high-resolution one scan line data is read from the 1200 DPI character graphics data shown in FIG. 6 (step S11), and character color information is further read (step S12). Subsequently, the high-resolution one scan line data is converted into a low resolution (steps S13 to S15), and then a minute flag indicating the positional relationship of the high resolution scan line at the low resolution is generated (steps S16 to S24). ). FIG. 18 shows the relationship between scan line drawing and minute flags. Subsequently, the RGB value and the minute pixel information at the low resolution (600 DPI) coordinates of the X start point are read (steps S25 and S26). Subsequently, the minute pixel information of the X starting point is generated from the minute flag information obtained previously (steps S27 to S35). Subsequently, the generated minute flag information is ORed with the information of the minute pixel read in 16), and rewritten again (step S36). The determination in step S27 is that if the pixel to be drawn is the same as the character color or if it is white (nothing is drawn), the minute pixel processing is performed, and if not, the minute pixel processing is not performed. In other words, since only one piece of low resolution color information is included, it is necessary to save the background color and the character color when performing minute pixel processing on a pixel that has already been drawn, but this is not possible. Such a judgment is necessary. This will be described with reference to FIGS. Subsequently, the character color information is written in the RGB band (step S37).

  Subsequently, as shown in FIG. 17, in steps S38 to S49, similarly to the X start point, pixel drawing processing from the X start point +1 to the X end point -1 is performed. In step S42, if the pixel to be drawn is the same as the character color or white background (nothing is drawn), the minute pixel processing is performed, and if not, the minute pixel processing is not performed. In other words, since only one piece of low resolution color information is included, it is necessary to save the background color and the character color when performing minute pixel processing on a pixel that has already been drawn. Such a judgment is necessary. Subsequently, as shown in FIG. 18, in steps S50 to S62, the X end point pixel drawing process is performed in the same manner as the X start point. In step S52, if the pixel to be drawn is the same as the character color or white background (nothing is drawn), the minute pixel process is performed. If not, the minute pixel process is not performed. In other words, since only one piece of low resolution color information is included, it is necessary to save the background color and the character color when performing minute pixel processing on a pixel that has already been drawn. Such a determination is necessary. In step S63, it is determined whether or not all scan line drawing has been completed. If it has not been completed, the process returns to step S11.

  FIG. 19 shows the relationship between scan line drawing and minute flags. The minute pixels corresponding to the low resolution (600 DPI) RGB data are thus stored at the high resolution (1200 DPI).

  Drawing examples are shown in FIGS. 21 and 22 along the lines indicated by the arrows in FIG. In FIG. 21, the RGB values are drawn in the RGB band in the previous line before drawing this line. The line shown in FIG. 20 is drawn in FIG. Since the RGB value to be drawn is the same as the RGB value of the character as shown in FIGS. 16 to 18, the minute pixel is ORed to the previous minute pixel for drawing.

  FIG. 23 is a block diagram showing a configuration of the image processing apparatus according to the embodiment of the present invention. In FIG. 23, the bus arbiter I / F 151 arbitrates requests to the bus arbiters of the image processing parameter reading device 152, the RGB band image reading device 153, the post-image processing image writing device 155, and the minute pixel data reading device 154. . The image processing parameter reading device 152 reads various parameters from the image processing parameter memory area 114e of the main memory 114 via the bus arbiter I / F 151, and transfers them to the image processing parameter storage devices 157 to 162. The parameter address generation device 163 generates an address for reading various parameters from the image processing parameter memory area 114e of the main memory 114. The DMA parameter storage device 157 receives the multi-value RGB bandwidth, multi-value RGB band height, RGB band start address, post-tone processing CMYK bandwidth, post-tone processing CMYK band height received from the image processing parameter reading device 156. , CMYK band start address, minute pixel band start address, and the like are stored. The lattice point data storage device 158 stores lattice point data of the main memory 114 necessary for the color conversion processing device 164 received from the image processing parameter reading device 152. The gamma table storage device 159 stores gamma data of the main memory 114 necessary for the color conversion processing device 164 received from the image processing parameter reading device 136.

  The minute pixel color storage device 160 stores data of the main memory 114 necessary for the resolution conversion device 165 received from the image processing parameter reading device 152. The halftone parameter storage device 161 stores the halftone parameters of the main memory 114 necessary for the halftone processing device 166 received from the image processing parameter reading device 152. The threshold matrix storage device 162 stores a threshold matrix of the main memory 114 necessary for the halftone processing device 166 received from the image processing parameter reading device 152.

  The RGB band image reading device 153 reads an RGB band image from the RGB band memory region 114 c of the main memory 114 via the bus arbiter I / F 151, and transfers it to the RGB data buffer device 167. The band image address generation device 168 generates an address for reading an RGB image in units of horizontal lines from the RGB band memory area 114 c of the main memory 114. The RGB data buffer device 167 reads the RGB band image data from the RGB band image reading device 153 and transfers it to the RGB data clipping device 169. The RGB data cutout device 169 cuts out 24-bit RGB data from the 32-bit unit data as shown in FIG. 9 transferred from the RGB data buffer device 167 and transfers it to the color conversion processing device 164.

  The minute pixel data reading device 154 transfers the minute band image from the minute pixel band memory area 114 d of the main memory 114 to the minute pixel data buffer device 170 that reads the minute band image via the bus arbiter I / F 151. The minute pixel data dress generation device 171 generates an address for reading minute pixel data from the minute pixel band memory area 114 d of the main memory 114. The minute pixel data buffer device 170 reads minute pixel data from the minute pixel data reading device 154 and transfers it to the minute pixel line storage device 172. The minute pixel line storage device 172 stores minute pixel data transferred from the minute pixel data buffer device 170 for one line.

  The color conversion processing device 164 reads RGB values from the RGB data cutout device 169, performs RGB → CMY color conversion processing and BG / UCR processing, selects one version from the generated multi-value CMYK data, and selects a multi-value CMYK line. Transfer to the storage device 173. The multi-value CMYK line storage device 173 stores the multi-value CMYK data transferred from the color conversion processing device 164 for one line.

  The resolution conversion device 165 reads the processed image data and minute pixel data received from the multi-value CMYK line storage device 173 and the minute pixel line storage device 172, performs resolution conversion processing at 600 → 1200 DPI, and transfers to the halftone processing device 166. . FIG. 23 shows a block diagram. The halftone processing device 166 reads the threshold matrix from the threshold matrix storage device 162, receives the data after resolution conversion from the resolution conversion device 165, executes halftone processing, and performs image processing in units of words in the memory. The data after gradation processing is transferred to the subsequent image buffer device 174.

  The post-image processing image buffer device 174 temporarily stores a plurality of word data in order to perform a plurality of efficient burst transfers of the image data processed by the halftone processing device 166 through the bus 116. The post-image processing image writing device 155 writes a plurality of words of image data into the post-gradation processing page memory area 114f of the main memory 114 via the bus arbiter I / F 151. At this time, a plurality of data at consecutive addresses are transferred through the bus to perform a plurality of efficient burst transfers. The post-image processing image address generation device 175 performs an address calculation of the band memory area of the main memory 114. At this time, since the RGB band image is read in units of horizontal lines, the post-image processing image also generates an address in units of horizontal lines.

  FIG. 24 is a flowchart showing the processing operation of the image processing apparatus according to the embodiment of the present invention. In FIG. 24, first, the band line counter is initialized to 0 (step S81), and the RGB band image data of the band line counter line is read and transferred to the color conversion processing device 164 (step S82). Subsequently, the attribute data of the attribute band of the source line counter is read and transferred to an attribute line storage device (not shown) (step S83). Subsequently, the resolution conversion flag is initialized to 0 (step S84), and the line memory read address is further initialized (step S85). Subsequently, the color conversion processing device 164 reads an RGB value for each pixel from a multi-value R, G, B line storage device (not shown), reads an attribute value from an attribute line storage device (not shown), and changes the color according to the attribute. The conversion table is switched, RGB → CMYK color conversion is performed to generate a C-plane pixel, and it is transferred to the multi-value CMYK line storage device 173 (step S86). Subsequently, data for one line is stored in the multi-valued CMYK line storage device 173 (step S87). Further, the resolution conversion device 165 converts the resolution of the C-plate image data into minute data and transfers it to the halftone processing device 166 (step S88). Subsequently, the halftone processing device 166 performs halftone processing by switching the threshold value table of the image data after the resolution conversion by the attribute data, transfers the image data to the post-image processing buffer device 174, and transfers it to the C-page page memory via the bus. Transfer to the area (see FIG. 5) (step S89). Next, it is determined whether or not one line of image data has been processed (step S90). If one line of image data has not been processed, the line memory read address is incremented by one (step 91). Return to S88.

  If the image data for one line is processed in step S90, the line memory read address is set to 0 (step S92), and the resolution conversion device 165 converts the resolution of the M-plane image data with minute data, and the halftone processing device. Transfer to 166 (step S93). Subsequently, the halftone processing device 166 performs halftone processing by switching the threshold value table of the image data after resolution conversion according to the attribute data, transfers the image data to the post-image processing buffer device 174, and transfers the M-page page memory via the bus. Transfer to the area (see FIG. 5) (step S94). Next, it is determined whether or not one line of image data has been processed (step S95). If one line of image data has not been processed, the line memory read address is incremented by one (step 96). Return to S92.

  If image data for one line is processed in step S95, the Y plate is drawn in the same manner as the C plate (step S97), and the K plate is drawn in the same manner as the C plate (step S98). Thereafter, the resolution conversion flag is checked (step S99). As a result, the resolution conversion flag is set to 1 in step S100 and the process returns to step SS85. On the other hand, in step S101, it is determined whether or not the band line counter <RGB band height. If it is determined that the band line counter <RGB band height, the band line counter is incremented by one (step S102), and the process returns to step S82 to execute the subsequent processing. In this way, the above processing is executed until the band line counter reaches the RGB band height.

  FIG. 25 is a block diagram showing a configuration of the resolution conversion apparatus according to the embodiment of the present invention. In FIG. 25, a register 181 receives CMYK data from the multilevel CMYK line storage device 173, temporarily stores it, and transfers it to the MUX 187. The register 182 temporarily stores the zeroth DOT pixel of the minute pixel from the minute pixel line storage device 172 and transfers it to the MUX 186. The register 183 temporarily stores the first DOT pixel of the minute pixel from the minute pixel line storage device 172 and transfers it to the MUX 186. The register 184 temporarily stores the second DOT pixel of the minute pixel from the minute pixel line storage device 172 and transfers it to the MUX 186. The register 185 temporarily stores the third DOT pixel of the minute pixel from the minute pixel line storage device 172 and transfers it to the MUX 186. The MUX 186 sequentially selects the subsequent MUX 187 from the DOT image flags in the registers 182 to 185 as shown in the flowchart of FIG. The MUX 187 switches between color information in the register 181 and white (0 value), and transfers it to the halftone processing device 166 in FIG.

  26 and 27 are flowcharts showing the processing operation of the resolution conversion processing according to the embodiment of the present invention. In this figure, first, the resolution conversion flag is initialized to 0 (step S111), and the line read address is initialized to 0 (step S112). Subsequently, the C version image data indicated by the line memory read address is read from the multilevel CMYK line storage device 173 (step S113), and the minute image data indicated by the line memory read address is further read from the minute pixel line storage device 172 (step S113). S114). After that, when the resolution conversion flag is 0, it is determined whether 0 pixel of the minute pixel = 1, or when the resolution conversion flag is 1, whether the pixel is 2 of the minute pixel = 1 (step S115). If the determination is NO, the value of white (0 value) is transferred to the halftone processing device 166 (step S116). On the other hand, if the determination in step S115 is YES, the value of the C plane image data is transferred to the halftone processing device 166 (step S117). Subsequently, when the resolution conversion flag is 0, it is determined whether 1 pixel of the minute pixel = 1, or when the resolution conversion flag is 1, 3 pixels of the minute pixel = 1 (step S118). If the determination is NO, the value of white (0 value) is transferred to the halftone processing device 166 (step S119). On the other hand, if the determination in step S118 is YES, the value of the C plane image data is transferred to the halftone processing device 166 (step S120). Next, it is determined whether or not image data for one line has been processed (step S121). If the determination is NO, the line memory read flag is incremented by one (step S122), and the process returns to step S113. On the other hand, if the determination is YES in step S121, the line memory read address is initialized to 0 (step S123), and the M image data indicated by the line memory read address is read from the multilevel CMYK line storage device 173 (step S124). Subsequently, the minute image data indicated by the line memory reading address is read from the minute pixel line storage device 172 (step S125). Next, when the resolution conversion flag is 0, it is determined whether or not the minute pixel 0 pixel = 1, or when the resolution conversion flag is 1, the minute pixel 2 pixel = 1 (step S126). If the determination is NO, the value of white (0 value) is transferred to the halftone processing device 166 (step S127). On the other hand, if the determination in step S126 is YES, the value of the M plane image data is transferred to the halftone processing device 166 (step S128). Subsequently, when the resolution conversion flag is 0, it is determined whether 1 pixel of the minute pixel = 1, or when the resolution conversion flag is 1, 3 pixels of the minute pixel = 1 (step S129). If the determination is NO, the value of white (0 value) is transferred to the halftone processing device 166 (step S130). On the other hand, if the determination in step S129 is YES, the value of the M plane image data is transferred to the halftone processing device 166 (step S131). Next, it is determined whether or not image data for one line has been processed (step S132). If the determination is NO, the line memory read flag is incremented by one (step S133), and the process returns to step S123. On the other hand, if the determination is YES in step S132, the Y and K versions are processed in the same manner as described above (step S134), the resolution conversion flag is checked (step S135), and if the determination is NO, the resolution flag is set to 1 (step S136) If the determination is YES, this process ends.

  In the above, the method of drawing with RGB images in the band memory has been described, but the same can be considered for CMY and CMYK images.

  As described above, according to this embodiment, in a portion where high image quality such as characters is required at the time of image generation by a printer, the shape of a minute pixel inside one pixel is used for each pixel as a minute pixel. High resolution printing is possible by storing, adding color information of minute pixels, expanding the minute pixels, and converting the resolution during image processing.

  By the way, the image processing method (operation) in the embodiment described so far can be programmed, recorded on a computer-readable recording medium, and executed on the computer. Further, a part of the image processing method can be provided on a network and realized through a communication line.

  That is, the image processing method described in this embodiment is realized by executing a program prepared in advance on a computer (CPU 130) such as a personal computer or a workstation as shown in FIG. This program is operated by a computer such as a memory 131, a hard disk 134, a flexible disk 137, a CD-ROM (Compact-Disc Read Only Memory) 136, a MO (Magneto Optical), a DVD (Digital Versatile Disc), etc. by operating the keyboard 35 or the like. The program is recorded on a readable recording medium, read from the recording medium by a computer (CPU 130), and displayed on the display device 133 as necessary. In addition, data of this image processing method can be transmitted and received from the communication device 132 to an external device as necessary.

  In addition, as shown in FIG. 29, this program can be distributed to devices 141 to 143 such as a personal computer via the recording medium via a network such as the Internet 30.

  That is, this program can be provided in a state of being installed in advance on a hard disk as a recording medium built in the computer, for example. The program can be provided as packaged software by temporarily or permanently storing it in a recording medium and incorporating it as a unit in a computer or using it as a removable recording medium.

  As the recording medium, for example, a flexible disk, a CD-ROM, an MO disk, a DVD, a magnetic disk, a semiconductor memory, and the like can be used.

  The program can be transferred from a download site to a computer wired or wirelessly via a network such as a LAN (Local Area Network) or the Internet, and downloaded to a storage device such as a built-in hard disk in the computer. .

  Further, the processing in the image processing apparatus described in the above-described best mode for carrying out the present invention can be provided in the form of a program realized by a computer (for example, CPU 130).

  FIG. 30 is a block diagram showing a hardware configuration of such a multifunction machine. As shown in the figure, the MFP 300 has a configuration in which the controller 10 and an engine unit (Engine) 360 are connected by a PCI (Peripheral Component Interconnect) bus. The controller 310 is a controller that controls the entire multifunction device 1 and controls drawing, communication, and input from an operation unit (not shown). The engine unit 360 is a printer engine that can be connected to a PCI bus, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 360 includes an image processing part such as error diffusion and gamma conversion in addition to a so-called engine part such as a plotter.

  The controller 310 includes a CPU 311, a north bridge (NB) 313, a system memory (MEM-P) 312, a south bridge (SB) 314, a local memory (MEM-C) 317, and an ASIC (Application Specific Integrated Circuit). 316 and a hard disk drive (HDD) 318, and the north bridge (NB) 313 and the ASIC 316 are connected by an AGP (Accelerated Graphics Port) bus 315. The MEM-P 312 further includes a ROM (Read Only Memory) 312a and a RAM (Random Access Memory) 312b.

  The CPU 311 performs overall control of the multifunction peripheral 300, has a chip set including the NB 313, the MEM-P 312 and the SB 314, and is connected to other devices via this chip set.

  The NB 313 is a bridge for connecting the CPU 311 to the MEM-P 312, SB 314, and AGP 315, and includes a memory controller that controls reading and writing to the MEM-P 312, a PCI master, and an AGP target.

  The MEM-P 312 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 312a and a RAM 312b. The ROM 312a is a read-only memory used as a memory for storing programs and data, and the RAM 312b is a writable and readable memory used as a program and data development memory, a printer drawing memory, and the like.

  The SB 314 is a bridge for connecting the NB 313 to a PCI device and peripheral devices. The SB 314 is connected to the NB 313 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 316 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and has a role of a bridge for connecting the AGP 315, the PCI bus, the HDD 318, and the MEM-C 317. The ASIC 316 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 316, a memory controller that controls the MEM-C 317, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. Access Controller) and a PCI unit that performs data transfer between the engine unit 60 via the PCI bus. The ASIC 316 is connected to an FCU (Fax Control Unit) 330, a USB (Universal Serial Bus) 40, and an IEEE 1394 (The Institute of Electrical and Electronics Engineers 1394) interface 350 via a PCI bus.

  A MEM-C 317 is a local memory used as a copy image buffer and a code buffer, and an HDD (Hard Disk Drive) 318 is a storage for storing image data, programs, font data, and forms. It is.

  The AGP 315 is a bus interface for a graphics accelerator card that has been proposed to speed up graphics processing, and speeds up the graphics accelerator card by directly accessing the MEM-P 312 with high throughput. .

  As described above, the image processing apparatus, the image processing method, and the program according to the present invention are useful for a digital copying machine, a digital camera, a scanner, a printer, and the like, and particularly, a portion that requires high image quality such as characters when generating an image. In the case of a small pixel, the shape of a minute pixel inside one pixel is stored in each pixel unit, color information of the minute pixel is added, and the resolution is converted by developing the minute pixel at the time of image processing. Suitable for processing.

It is a figure which shows the structural example of the mechanism part of the multi-color image forming apparatus which implemented this invention. It is a block diagram which shows the structure of the electrical equipment / control apparatus in FIG. It is a block diagram which shows the flow of the image processing concerning embodiment of this invention. It is a block diagram which shows the concept of the image processing concerning embodiment of this invention. It is explanatory drawing which shows the example of a format of the main memory concerning embodiment of this invention. It is explanatory drawing which shows the example of the graphics data for characters concerning embodiment of this invention. It is explanatory drawing which shows the memory format of the graphics data for characters of the main memory concerning embodiment of this invention. It is explanatory drawing which shows the RGB band image memory format of the main memory concerning embodiment of this invention. It is explanatory drawing which shows the micro pixel band memory format of the main memory concerning embodiment of this invention. It is explanatory drawing which shows the example of a 1200DPI character drawing concerning embodiment of this invention. It is explanatory drawing which shows the example of the RGB band image data (low resolution) concerning embodiment of this invention. It is explanatory drawing which shows the example of the micro pixel band image expressed by the micro image in 600 DPI. It is explanatory drawing which shows the example which printed the actual character. It is a flowchart which shows the operation | movement process of the whole image processing concerning embodiment of this invention. It is explanatory drawing which shows the concept of the character drawing process concerning embodiment of this invention. It is a flowchart which shows the processing operation (1) of the character drawing process concerning embodiment of this invention. It is a flowchart which shows the processing operation (2) of the character drawing process concerning embodiment of this invention. It is a flowchart which shows the processing operation (3) of the character drawing process concerning embodiment of this invention. It is explanatory drawing which shows the relationship between scanning line drawing and a micro flag. It is explanatory drawing which shows the example of a drawing process concerning embodiment of this invention. It is explanatory drawing which shows the state of the minute pixel data and RGB data before drawing. It is explanatory drawing which shows the state of the minute pixel data after drawing, and RGB data. It is a block diagram which shows the structure of the image processing apparatus concerning embodiment of this invention. It is a flowchart which shows the processing operation of the image processing apparatus concerning embodiment of this invention. It is a block diagram which shows the structure of the resolution conversion apparatus concerning embodiment of this invention. It is a flowchart which shows the processing operation (1) of the resolution conversion process concerning embodiment of this invention. It is a flowchart which shows the processing operation (2) of the resolution conversion process concerning embodiment of this invention. It is a block diagram which shows the example which makes a computer perform the image processing method concerning embodiment of this invention. It is a block diagram which shows the example which downloads and performs the image processing method concerning embodiment of this invention from a network. It is a block diagram which shows the hardware constitutions of this compound machine.

Explanation of symbols

101 CPU
DESCRIPTION OF SYMBOLS 105 Drawing apparatus 110 Image processing apparatus 114 Main memory 114a PDL memory area 114b Graphics memory area for characters 114c RGB band memory area 114d Minute pixel band memory area 114e Image processing parameter memory area 114f Gradation processed page memory area 164 Color conversion processing apparatus 165 Resolution converter 166 Halftone processor

Claims (6)

High resolution graphics data generation means for analyzing input information and generating high resolution graphics data;
Low-resolution color information rendering means for reading data generated by the high-resolution graphics data generation means and rendering low-resolution color information;
Low resolution color information storage means for storing an image generated by the low resolution color information drawing means;
High-definition shape drawing means for reading data generated by the high-resolution graphics data generation means and generating high-resolution minute pixel shape information;
Micropixel shape storage means for storing micropixel shape information generated by the high-definition shape drawing means;
High resolution conversion means for converting to high resolution using the color information stored in the low resolution color information storage means and the minute pixel shape information stored in the minute pixel shape storage means;
An image processing apparatus comprising:   Read the color information stored in the low-resolution color information storage means, determine that the color is the same as the color for drawing the high-definition shape, or a white background, and store the minute pixel shape stored in the minute pixel shape storage means 2. The image processing apparatus according to claim 1, wherein the pixel shape information to be newly drawn on the information is ORed and stored again in the minute pixel shape storage means.   Read the color information stored in the low-resolution color information storage means, determine that the color is not the same as the color for drawing the high-definition shape or that it is not white, and do not change the minute pixel shape information in the minute pixel shape storage means The image processing apparatus according to claim 1.   2. A high-resolution conversion unit that reads color information stored by the color information storage unit and micro-pixel shape information stored in the micro-pixel shape storage unit in units of lines and performs resolution conversion. An image processing apparatus according to 1. An image processing method executed by an image processing apparatus,
The image processing apparatus includes a low-resolution color information storage unit and a minute pixel shape storage unit,
A high-resolution graphics data generation step of analyzing input information by high-resolution graphics data generation means to generate high-resolution graphics data;
A low-resolution color information rendering unit that reads data generated in the high-resolution graphics data generation step by a low-resolution color information rendering unit, renders low-resolution color information, and stores the low-resolution color information storage unit;
A fine shape drawing step of reading the data generated by the high resolution graphics data generating means by the high definition shape drawing means, generating high resolution minute pixel shape information, and storing the data in the minute pixel shape storage means;
A high-resolution conversion step of converting the color information stored in the low-resolution color information storage unit by the high-resolution conversion unit to a high resolution using the micro-pixel shape information stored in the micro-pixel shape storage unit;
And an image processing method.   A program for causing a computer to execute the image processing method according to claim 5.

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