JP3743471B2 - Printing system, printing apparatus and printing control apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing system, a printing apparatus, and a printing control apparatus that perform color printing, and in particular, encodes a color image to reduce a fixed amount of information, shortens the transfer time of color image information, and performs color conversion processing and correction. The present invention relates to a printing system or the like that realizes performance improvement by speeding up processing and reduction in price by reducing the amount of memory for storing color image information.
[0002]
[Prior art]
As a conventional color printing method, for example, print data is rasterized into color image information by a host device such as a personal computer, the rasterized color image information is encoded and sent to the color printer control device, and encoded by the color printer control device. There is a method in which the color image information is decoded, converted into data that can be sent to the color printer device, sent to the color printer device, and color printing is performed.
[0003]
In this case, for a binary printer whether or not the color printer device adds a color such as an inkjet printer, the color image information rasterized by the host device is subjected to pseudo gradation processing such as area gradation and error diffusion. The data converted into binary data is generally subjected to run length encoding such as MH and MMR which are international standards.
[0004]
For a printer device capable of multi-tone output, such as a sublimation printer, the color printer device generally performs encoding such as JPEG which is an international standard.
[0005]
[Problems to be solved by the invention]
In the conventional encoding such as JPEG, it is difficult to increase the speed because it is necessary to perform color conversion processing and correction processing for each pixel. Further, since there is no characteristic of reducing the amount of information by a fixed amount, it is difficult to rotate the color image information and print it out at high speed, or to reduce the amount of memory for storing the color image information.
[0006]
As an encoding technique that can reduce the amount of information of a color image by a fixed amount, there is a technique disclosed in Japanese Patent Publication No. 6-7688.
[0007]
An object of the present invention is to provide a printing system or the like that can realize high-speed color printing by performing color printing by applying this encoding technique to an actual printing system.
[0008]
In addition, according to the present invention, it is possible to shorten the transfer time of color image information, speed up color conversion processing and correction processing, improve performance by speeding up rotation processing of color image information, and reduce the amount of memory for storing color image information. Realize low price, provide high-performance and inexpensive color printing system.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention creates and outputs encoded information using an encoding technique in which color image information is reduced by a fixed amount in a host device, and the print control apparatus stores the encoded information in a page memory. Store the color image information obtained by decoding and decoding the encoded information read from the page memory in the line buffer, while reading the color image information previously stored in the line buffer and outputting it to the printing device, thereby printing with the host device The amount of communication between control devices can be reduced, and the amount of memory can also be reduced.
[0010]
For printing devices with limited gradation output, a circuit for performing pseudo gradation processing such as area gradation and error diffusion is arranged between the printing device and the line buffer, so that the above color image can be obtained. We realized that the encoding technology with a fixed amount of information was applied to a printing system using a printing device with limited gradation output.
[0011]
In general, color information of each pixel of color image information used in a host device is composed of gradation values of three primary colors of red (red), green (green), and blue (blue). Is color-printed with three primary colors of cyan, magenta, and yellow, or four primary colors of cyan, magenta, yellow, and black, or toner, so red (red) and green are used for printing devices. It is necessary to convert the three primary colors (green) and blue (blue) into the three primary colors cyan, magenta, and yellow or the four primary colors cyan, magenta, yellow, and black. It is also necessary to correct density characteristics for the tone values of the three primary colors cyan, magenta, and yellow, or the four primary colors cyan, magenta, yellow, and black, which are output by a color printer apparatus called gamma correction.
[0012]
By arranging these correction circuits between the page memory and the decoding circuit, color correction can be performed with the number of pixels being reduced by a fixed amount, so that the processing time can be shortened.
[0013]
Similarly, a rotation circuit for rotating an image is also arranged between the page memory and the decoding circuit, and the processing time can be shortened because the number of pixels can be reduced.
[0014]
To give a more specific example, the color information of each pixel of the color image information rasterized by the host device is the primary colors of red (red), green (green), and blue (blue), and the colors 0 to 255. If it is composed of tone values, the amount of information per pixel is 24 bits (= 8 bits / color × 3 colors). If this is encoded with two approximate colors representing a block of 4 × 4 pixels (= 16 pixels), 64 bits (= 24) of 1/6 of 384 bits (= 16 pixels × 24 bits). (Bit × 2 colors + 16 pixels × 1 bit), the color image information transfer time from the host device to the printer control device can be shortened to 1/6.
[0015]
Also, conversion of the three primary colors of red (red), green (green) and blue (blue) to the three primary colors of cyan, magenta and yellow or the four primary colors of cyan, magenta, yellow and black, and The correction of density characteristics for the gradation values of the three primary colors cyan, magenta, and yellow, or the four primary colors cyan, magenta, yellow, and black that are output from the color printer requires 16 pixels. Therefore, the color conversion process and the correction process can be reduced to 1/8, and the speed can be increased.
[0016]
Further, since the encoded information amount and information format per block can be fixed, a color image is rotated by 90, 180, and 270 degrees and encoded, or when encoded color image information is decoded. , 180, and 270 degrees, it is also possible to decode at high speed. Therefore, the color image information with the information amount reduced to 1/6 is stored in the memory as it is encoded, and the paper is transported in the color printer. In addition, since the color image can be output upright or rotated 90, 180, and 270 degrees, the memory capacity for storing color image information in the color printer control device can be reduced to 1/6.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0018]
[Example 1]
FIG. 1 shows the configuration of an embodiment of a color printing system to which the present invention is applied. The color printing system includes a color printer device 102 using, for example, a laser beam method for realizing print data given on printing paper, a color printer control device 101 for controlling the color printer device 102, and a color printer control device. It is composed of a host device 100 that issues a print instruction to 101.
[0019]
The host device reads the color image from the print data storage memory 200, the color image generation unit 106 that generates a color image from the print data, the image memory 201 that stores the color image generated by the color image generation unit 106, and the image memory 201, It includes an encoding processing unit 107 that performs encoding processing by a method that will be described later, and an encoding information buffer 202 that stores encoded information that has been encoded. Also, the control unit 109 that controls each component and outputs a print instruction and the like, and the communication with the color printer control apparatus 101 such as sending the print instruction and encoding information for print processing to the color printer control apparatus 101 A communication unit 108 is provided.
[0020]
The color printer control device 101 includes a page memory 103 that stores the encoded information received from the host device, a print output unit that processes the encoded information and outputs the processed information to the color printer device 102, and the overall operation of the color printer control device. The MPU 104 to be controlled is a main component. Details of the print output unit will be described with reference to FIG.
[0021]
FIG. 2 is a diagram for explaining print data processing of the host apparatus 100.
[0022]
The print data includes information such as character data, graphic data, and image data. The print data 200 is rasterized by the color image generation unit 106 to generate color image information. The encoding processing unit 107 divides the color image into blocks of 4 × 4 pixels (= 16 pixels) adjacent to each other, and obtains two approximate colors (2041, 2042) representing the block 203. Then, resolution information 2043 indicating which approximate color (2041, 2042) each pixel included in the block can be classified is added to generate encoded information. An example of generating encoded information from color image information can be confirmed in detail in Japanese Patent Publication No. 6-7688.
[0023]
The color printer apparatus 102 of this embodiment outputs three primary colors of yellow, magenta, and cyan with gradations (= 0 to 255), and outputs color information 203 of the encoded color image information 202. It is assumed to be composed of three primary colors of yellow, magenta, and cyan.
[0024]
As the information for one pixel, an example of 24 bits including information on cyan (C), magenta (M), and yellow (Y) is often used. In this example (the example of FIG. 2), since the block is divided by 4 × 4 pixels, the color image information before encoding is 348 bits per block, but the approximate color of two colors by the encoding process. Since the approximate color of (24 bits × 2) and 16 pixels is divided by (0, 1), the amount of information can be reduced to 64 bits of plus 16 bits. The same can be said for color information defined by red (R), green (G), and blue (B).
[0025]
FIG. 3 is a color diagram showing details of the components of the print output unit 105 that decodes the encoded color image information 202 and separates it into cyan, magenta, and yellow tone values and sends them to the color printer apparatus 102. It is a figure of a printing control apparatus.
[0026]
Under the control of the MPU unit 104, the color printer control apparatus 101 sequentially stores the encoded color image information (encoded information) 202 received from the host apparatus 100 in the page memory 103, and stores the encoded information 202 for one page. When all are stored in the page memory 103, the color image information 202 encoded by the print output unit 105 is decoded and separated into gradation values of yellow, magenta, and cyan colors, and the order of colors output by the color printer device 102, for example, The gradation values of each color are sent to the printer apparatus 102 in the order of yellow, magenta, and cyan. The print output unit 105 for explaining the configuration and operation of the print output unit 105 in FIG. 3 includes an input circuit 300, a decoding circuit 301, a line buffer 302, a raster output circuit 303, a color information separation / extraction circuit 304, and a transmission circuit 305. . First, the print output unit 105 sequentially reads the color image information 202 encoded from the page memory 103 by the input circuit 300 and passes it to the block decoding circuit 301. The decoding circuit 301 divides the received color image information into blocks, performs decoding processing for each block, and stores the decoded new color image information (decoded color image information) 306 for four rasters in the line buffer 302. In the decoding circuit processing, the approximate color of each pixel in the block is obtained based on the resolution information of the encoded information, the color information of the approximate color is assigned to each 4 × 4 pixel, and the color image information of each block is obtained. It is a process to generate.
[0027]
The raster output circuit 303 outputs the decoded color image information 306 stored in the line buffer 302 for each raster, and the color information separation / extraction circuit 304 separates the color information 307 of the decoded color image information 306 to separate the MPU unit 104. The color gradation value of any one of yellow, magenta, and cyan is extracted in the order of the colors output by the color printer device 102 instructed by. The separated and extracted yellow, magenta, and cyan tone values are sent to the printer apparatus 102 by the sending circuit 305.
[0028]
For the purpose of reducing or deleting the capacity of the line buffer 302, a color information separation / extraction circuit 304 is arranged before storing the decoded color image information 306 in the line buffer 302, and yellow, which the MPU unit 104 instructs, Either magenta or cyan may be extracted and stored in the line buffer 302. Alternatively, the data may be output directly to the printer device without being stored in the line buffer 302.
[0029]
In this way, the color image information is encoded by the host device, and the received encoded information is stored for each page as it is in the page memory of the color printer control device, and the color printer device has three colors of cyan, magenta, and yellow. By restoring the color image information encoded when the primary color gradation value is transmitted, the transfer time can be shortened by reducing the communication information amount, and the fixed amount of the page memory capacity can be reduced.
[0030]
[Example 2]
Next, the color printer controller outputs the color image information received from the host device to the color printer for which the gradation output of the primary colors of cyan, magenta, and yellow is limited. FIG. 1 shows an embodiment in which color information of gradation values limited to three primary colors of cyan, magenta, and yellow is converted by area gradation processing to be transmitted and sent to a color printer for color printing. This will be described with reference to FIGS.
[0031]
The main configuration of the apparatus constituting the color printing system and the color printer control apparatus 101 is the same as that shown in FIG. As shown in FIG. 4, an area gradation circuit 400 is provided at the next stage of the color information separation / extraction circuit 304 of the configuration of the print output unit 105.
[0032]
The print output unit 105 outputs the decoded color image information 306 stored in the line buffer 302 by the raster output circuit 303 for each raster, and separates the color information 307 of the color image information 306 by the color information separation / extraction circuit 304. Then, the gradation value of any one of yellow, magenta, and cyan is extracted in the order of colors output by the color printer device 102 instructed by the MPU unit 104.
[0033]
The gradation values of each color of yellow, magenta, and cyan separated / extracted by the color information separation / extraction circuit 304 are converted into gradation values that can be output by the color printer apparatus 102 by the area gradation circuit 400, and the transmission circuit 305 Is sent to the printer apparatus 102.
[0034]
A configuration example of the area gradation circuit 400 is shown in FIG. When the color printer apparatus 102 outputs 8 gradations and the area gradation circuit 400 outputs 8 gradations using a 4 × 4 16-gradation dither matrix 500, 128 gradations are output for each of the three primary colors, so approximately 2 million. Color expression of colors is possible.
[0035]
Hereinafter, an example of a specific operation of the area gradation circuit 400 will be described. For example, a yellow gradation value 500 is obtained from the color information 307 of the decoded color image information 306, and compared with a boundary value 503 defined in the dither matrix 504.
Boundary value 503 ≥ Gradation value 500
In this case, “0” is output for the limited gradation value 501,
Boundary value 503 <gradation value 500
In Case of,
(Gradation value 500−boundary value 503) <8
Then, “(gradation value 500−boundary value 503)” is output for the limited gradation value 501,
(Gradation value 500-boundary value 503) ≧ 8
Then, “8” is output for the limited gradation value 501.
[0036]
In this way, the color printer control apparatus performs pseudo gradation processing such as area gradation, and converts the gradation value of each pixel into a limited gradation value that can be output by the color printer apparatus for color printing. By arranging the area gradation circuit 400 after the color information separation / extraction circuit, it is possible to secure an amount of information that can express sufficient gradation as the color information of each pixel, and encode the color image information By reducing the fixed amount, the data transfer time can be shortened and the page memory can be reduced.
[0037]
[Example 3]
Next, the print data is rasterized into color image information in the host device, and the color information when the color image information is encoded is red (red; R), green (green; G), blue (blue; G). The color printer controller converts the color information of the three primary colors red, green, and blue into the four primary colors cyan, magenta, yellow, and black. An embodiment in which the color primary color tone values are sent to a color printer for color printing will be described with reference to FIGS.
[0038]
The main configuration of the apparatus constituting the color printing system and the color printer control apparatus 101 is the same as that shown in FIG. As shown in FIG. 6, a color conversion circuit 600 is provided before the decoding circuit 301 having the configuration of the print output unit 105.
[0039]
In the first embodiment shown in FIG. 3, the print output unit 105 sequentially reads out the color image information 202 encoded from the page memory 103 by the input circuit 300 for every four rasters and decodes the four rasters by the decoding circuit 301. The color image information 306 is stored in the line buffer 302.
[0040]
In the third embodiment, RGB color block data 601 constituting the color image information 202 encoded by the color conversion circuit 600 before inputting the encoded color image information 202 from the input circuit 300 to the decoding circuit 301 is stored. The color information 604 is input by converting the gradation values of the three primary colors of red, green, and blue in the color information 603 of the representative approximate color into the gradation values of the four primary colors of cyan, magenta, yellow, and black. Output CMYK block data 602 as a representative approximate color.
[0041]
The decoded circuit 301 decodes the converted block data 602 in the CMYK format, and the line buffer 302 stores color image information 306 represented by the gradation values of the four primary colors of cyan, magenta, yellow, and black. , Cyan, magenta, yellow, and black primary color tone values are sent to the printer 102.
[0042]
As a specific method of converting the gradation values of the three primary colors of red, green, and blue into the gradation values of the four primary colors of cyan, magenta, yellow, and black, there are three methods of red, green, and blue. The color complement is set to the gradation values of cyan, magenta, and yellow, respectively, and the gradation value of black is obtained from the combination of the gradation values of cyan, magenta, and yellow, and cyan, magenta, There is a method of removing the gradation value of yellow.
[0043]
[Example 4]
In addition, in connection with color conversion, a device that outputs three primary colors of red, green, and blue light such as a display and expresses the color, and four primary colors including cyan, magenta, and yellow, which are printers, and black. It is generally known that there is a difference in the visualized color from the device that outputs the color and outputs the color, and the technique and method for correcting this is often referred to as color correction.
[0044]
Furthermore, when printing with a printer or the like, the gradation output and the actual density (lightness on a display or the like) are not proportional, and a technique and method for correcting this is often referred to as gamma correction.
[0045]
One embodiment in the case of performing this color correction and gamma correction is shown in FIG. By providing a color correction circuit 700 and a gamma correction circuit 701 before and after the color conversion circuit 600, the RGB color block data 601 and the CMYK format block data 602 that constitute the encoded color image information are represented by representative approximate colors. Only perform color correction, color conversion, and gamma correction. Compared to the case where color correction, color conversion, and gamma correction are performed on all pixels, the number of pixels can be reduced to 1/8, and high-speed processing can be performed.
[0046]
Color conversion may be performed by a host device. In this case, color correction, color conversion, and gamma correction circuits are arranged in the subsequent stage of the encoding processing unit 107, and color image information is stored. After encoding, color correction, color conversion, and gamma correction can be performed only on the representative approximate color of the encoded color image information. With this arrangement, even when the host device has a color conversion function, processing can be performed at a higher speed than when color correction, color conversion, and gamma correction are performed on all pixels.
[0047]
[Example 5]
Next, when the encoded color image information is restored by the color printer controller, the read position and direction of the encoded color image information is changed and the resolution information of the encoded color image information is rearranged. , Cyan, magenta, and yellow will be described with reference to FIGS. 8, 9, and 10, in which tone values of the three primary colors, cyan, magenta, and yellow, are sent to a color printer apparatus and color images are rotated to perform color printing.
[0048]
The input circuit 300 of the output control unit 105 has a function of reading out the color image information 202 encoded in block units from the page memory in accordance with the reading direction corresponding to the rotation angle of the page designated by the MPU unit 104, and the subsequent stage of the input circuit 300 A rotation circuit 800 for rearranging the resolution information of each block of the encoded color image information read out in accordance with the rotation angle of the page is provided.
[0049]
Here, the color information is composed of the three primary colors of cyan, magenta, and yellow, and is composed of gradation values of 0 to 255 for each color, and is represented by two approximate colors representing a block of 4 × 4 pixels (= 16 pixels). When encoding is performed, the information amount of one block is fixed to 8 bytes (= 64 bits = 24 bits × 2 colors + 16 pixels × 1 bit).
[0050]
As shown in FIG. 10, when the horizontal × vertical pixel size of one page is 3,388 × 2,360 pixels, the encoded color image information is 847 × 590 blocks, and the encoded color image information is 3,997, It is fixed at 840 bytes (= 6,776 bytes × 590 = (847 × 8) × 590).
[0051]
In order to rotate and read out the encoded color image information, as shown in FIG. 10, 8 bytes are read for each block from each read start address according to the read direction, and the read address is updated. When reading in the reverse direction in the vertical direction, the next block is read from the address skipped in the reverse direction by 6,776 bytes, and when 847 blocks are read, 847 blocks are similarly read from the first block in the next column. This process is repeated for 590 columns to read the encoded color image information 202 for one page.
[0052]
In the rotation circuit 800, the encoded color image information 202 read from the page memory is input as data in units of blocks, and the resolution information is rearranged and output according to the rotation angle of the page specified by the MPU unit 104. In the decoding circuit 301, the encoded color image information in which the resolution information is rearranged according to the rotation angle of the page is input and the color image information is decoded, so that the decoded color image information 306 rotated for each block is output. The rearrangement order of the resolution information according to the rotation angle is as shown in FIG.
[0053]
Since the line buffer 302 stores the decoded color image information 306 corresponding to the rotation angle of the page, the gradation values of the three primary colors cyan, magenta, and yellow that have been rotated are sent to the printer apparatus 102.
[0054]
As described above, since color image information encoded by the encoding technique used in the present invention can be rotated and decoded at high speed, landscape (landscape) printing can be performed on a color printer that feeds paper in the longitudinal direction of paper. When printing data or printing portrait (vertically long) print data to a color printer that feeds the paper in the landscape direction, the page is rotated by 90 degrees and printed on the front side when duplex printing is performed. On the other hand, even when the reverse side is rotated 180 degrees and printed out, the encoded color image information only needs to be stored in the page memory. Therefore, it is necessary to increase the memory capacity even when the printed page is rotated. Absent.
[0055]
As for page rotation, the result of rotation when the color image information is encoded by the host device may be output. For example, in the case of printing output after rotating 90 degrees counterclockwise, the order of blocks to be encoded is performed in the order rotated 90 degrees counterclockwise as shown in FIG. Can be realized by rotating the array 90 degrees counterclockwise.
[0056]
【The invention's effect】
According to the present invention, it is possible to reduce the memory for storing image information with reduced transfer time by using encoding that reduces the amount of color image information by a fixed amount.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a main configuration of an embodiment of a color printer system.
FIG. 2 is a diagram illustrating an encoding process for print data.
FIG. 3 is a diagram showing a detailed configuration of a first embodiment of a color printer control apparatus.
FIG. 4 is a diagram illustrating a color printer control apparatus according to a second embodiment of the present invention that performs area gradation processing.
FIG. 5 shows an area gradation circuit.
FIG. 6 is a diagram illustrating a color printer control apparatus according to a third embodiment of the present invention that performs color conversion.
FIG. 7 is a diagram illustrating a color printer control apparatus according to a fourth embodiment of the present invention that performs correction, color conversion, and gamma correction.
FIG. 8 is a diagram illustrating a color printer control apparatus according to a fifth embodiment of the present invention that performs rotation processing.
FIG. 9 is a diagram showing a rotation circuit.
FIG. 10 is a diagram illustrating a read start position and a read direction of a page memory for rotation processing.
FIG. 11 is a diagram illustrating an example in which a rotation process is performed when color image information is encoded.
[Explanation of symbols]
100 ... Host device, 101 ... Color printer control device,
102 ... Color printer device, 103 ... Page memory, 104 ... MPU,
105 ... print output unit, 106 ... color image generation unit, 107 ... encoding processing unit,
108: Communication unit, 109: Control unit, 200: Print data, 201: Photosensitive belt,
202 ... encoded color image information, 203 ... pixel information of a block before encoding,
204: Information of the encoded block, 300: Input circuit, 301: Decoding circuit, 302: Line buffer, 303: Raster output circuit,
304: Color information separation / extraction circuit, 305 ... Sending circuit,
306 ... Decoded color image information,
307: Color information for one pixel of the decoded color image information,
400 ... area gradation circuit, 500 ... (input) gradation value,
501 ... gradation value to be output, 502 ... comparison / calculation unit, 503 ... boundary value,
504 ... Dither matrix, 505 ... Sub-scan direction raster coordinates,
506: Dot coordinates in the main scanning direction, 600: Color conversion circuit,
601 ... RGB format block data, 602 ... CMYK format block data,
603 ... RGB format block data color information,
604 ... Color information of CMYK format block data, 700 ... Color correction circuit,
701 ... Gamma correction circuit, 800 ... Rotation circuit, 900 ... Block data before rotation,
901: Block data after rotation, 110 ... Rotation 0 degree / 270 degree readout start position,
111 ... rotation 90 ° / 180 ° reading start position,
112 ... 0 degree rotation reading direction, 113 ... 90 degree rotation reading direction,
114 ... 180 degree rotation reading direction, 115 ... 270 degree reading direction,
116 ... unencoded color image information,
117 ... Encoded color image information (rotated 90 degrees),
118 ... arrangement of block pixels, 119 ... block data (rotated 90 degrees)

Claims (14)

The first color image information is formed by blocking the pixels constituting the first color image information for each of a plurality of adjacent pixels, and at least two approximate colors representing the pixels in the block are obtained, and the at least 2 Coding information is generated that includes color information that represents the gradation value of each primary color that is the basis of the approximate color of the color, and resolution information that indicates which of the approximate colors each pixel in the block corresponds to. A host device comprising: means; and communication means for outputting the encoded information;
A page memory for storing the encoded information received from the communication means, a decoding circuit for reading out the encoded information from the page memory and decoding it to generate second color image information, and a composite color image A print control device comprising: a line buffer for storing; and a sending circuit for reading out a second color image from the line buffer and sequentially outputting the second color image;
A printing system comprising: a printing apparatus that realizes second color image information output from the sending circuit on printing paper. The printing system according to claim 1.
The printing system, wherein the sending circuit includes a color information separation circuit that separates each primary color of the second color image read from the line buffer. The printing system according to claim 2.
The printing system includes an area gradation circuit that converts the separated primary colors output from the color information separation circuit into primary color data used in the printing apparatus. The printing system according to claim 1.
The first color image information and the encoding information are primary color configurations of red, green, and blue,
A color conversion circuit for converting the encoded information into second encoded information having a primary color configuration of yellow, cyan, and magenta and inputting the second encoded information to the decoding circuit between the page memory and the decoding circuit; Characteristic printing system. The printing system according to claim 4.
A printing system comprising a color correction circuit for correcting the color of the encoded information between the page memory and the decoding circuit. The printing system according to claim 4.
A printing system comprising a gamma correction circuit for performing gamma correction on the encoded information between the page memory and the decoding circuit. The printing system according to claim 1.
A printing system comprising: a rotation circuit that rotates the encoded information between the page memory and the decoding circuit. Information received from the host device, the pixels constituting the first color image information are blocked for each of a plurality of adjacent pixels, and at least two approximate colors representing the pixels in the block are obtained, Coding information comprising color information representing the gradation values of the respective primary colors that are the basis of at least two approximate colors and resolution information indicating which of the approximate colors each pixel in the block corresponds to A page memory to store, a decoding circuit that reads out and decodes the encoded information from the page memory and generates a second color image, a line buffer that stores the combined color image, and the second from the line buffer A sending circuit that reads out and sequentially outputs color images;
A printing apparatus comprising: a printing unit that realizes the second color image information output from the sending circuit on a paper surface. The printing apparatus according to claim 8.
The first color image information and the encoding information are primary color configurations of red, green, and blue,
A color conversion circuit for converting the encoded information into second encoded information having a primary color configuration of yellow, cyan, and magenta and inputting the second encoded information to the decoding circuit between the page memory and the decoding circuit; Characteristic printing device. The printing apparatus according to claim 8.
A printing apparatus comprising a rotation circuit for rotating the encoded information between the page memory and the decoding circuit. Information received from the host device, the pixels constituting the first color image information are blocked for each of a plurality of adjacent pixels, and at least two approximate colors representing the pixels in the block are obtained, Coding information comprising color information representing the gradation values of the respective primary colors that are the basis of at least two approximate colors and resolution information indicating which of the approximate colors each pixel in the block corresponds to A page memory to be stored and a decoding circuit that reads and decodes the encoded information from the page memory to generate a second color image;
A line buffer to store the combined color image;
A printing control apparatus comprising: a sending circuit that reads the second color image from the line buffer and sequentially outputs the second color image. 12. The print control apparatus according to claim 11, wherein the first color image information and the encoding information are primary color configurations of red, green, and blue,
A color conversion circuit for converting the encoded information into second encoded information having a primary color configuration of yellow, cyan, and magenta and inputting the second encoded information to the decoding circuit between the page memory and the decoding circuit; A printing control device. The printing control apparatus according to claim 11, wherein
A printing control apparatus comprising: a rotation circuit that rotates the encoded information between the page memory and the decoding circuit. The print control apparatus according to claim 13.
The rotating circuit has a function of sequentially reading the encoded information in the horizontal direction of the printing form, a function of reading out in the reverse order of the horizontal direction of the printing form, a function of sequentially reading out in the vertical direction of the printing form, and a function of reading in the vertical direction of the printing form. By providing an input circuit having a function of reading in reverse order and a rotation mechanism for rearranging and outputting resolution information of color image information encoded according to the reading direction and reading order, 0 degrees, 90 degrees, 180 degrees A print control apparatus that performs color printing with page rotation of 270 degrees.

Images