JP2007307712A - Printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speed up color conversion processing in a printing system. <P>SOLUTION: Original image data of a manuscript color space (RGB) is converted to image data for drawing of a drawing color space (CMYK) by a PC or a printer. A signature as unique digest data is generated from the original image data and is attached to a drawing command. The signature attached to the drawing command and a signature on a cache are compared with each other. If the signatures agree with each other, printing is carried out by acquiring and reusing image data for drawing on the cache. Unless the signatures agree with each other, printing is carried out by converting the data to the image data for drawing of the drawing color space (CMYK). The converted image data for drawing and its signature are stored in the cache. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing system, and more particularly, to a printing system that shortens color conversion processing time by reusing color-converted image data.

  In a conventional printing system, image data in an original color space (RGB space) is converted into image data in a printing color space (CMYK space) and printed. Since this color conversion has a large processing load, there is a method of reusing already converted image data for the same image data in order to shorten the processing time. Examples of related art related to this will be given below.

The “data conversion device” disclosed in Patent Document 1 converts document data information to data for an output device, and speeds up the process of developing the print data. Processing time is shortened by caching the processed print data and reusing it. When it is detected that the document information can be converted into data for the output device, the pseudo print command issuing means issues a pseudo print command independent of the user print command. In response to this, the printer driver converts the color depending on the display device included in the document information into a color space color dependent on the printer or a color space color independent of the output device. Correspondence between the color included in the document information and the color obtained by the color conversion process is held.
JP 2001-251527

  However, the conventional color conversion image data reuse method has the following problems. In order to increase the speed of the color conversion process, it must be converted once into a color space that does not depend on the device, and the increase in speed is hindered by that process. In a system in which print data generated by processing the original data of the application program by a printer driver is transmitted from the application program on the host computer to the printer connected by the host interface and printed out, a color image is added to the original data. Is included, a large number of color conversion processes (mainly conversion from the RGB color space to the CMYK color space) are performed, and thus the printing process takes time.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems, and to speed up color conversion processing without converting to a device-independent color space in a printing system that performs color conversion and printing of an original image. .

  In order to solve the above problems, in the present invention, as a drawing unit of a printing system, a signature generation unit that generates a signature that is unique digest data from original image data in a document color space, and a signature is attached to a drawing command. Means for verifying the signature attached to the rendering command and the signature on the cache memory, means for acquiring the corresponding drawing image data on the cache memory according to the match of the signature verification, and signature verification The original image data is converted into drawing image data in the drawing color space in accordance with the mismatch, and the converted drawing image data and the signature of the original image data are stored in the cache memory.

  With the configuration described above, it is possible to speed up the printout of document data in which the background is filled with a repeated pattern image. When the entire color conversion information of the pattern is cached and repeated, the color conversion result of the entire pattern stored in the cache can be reused as it is, and unnecessary color conversion processing does not occur. It is possible to speed up the printing output of document data in which the background is filled with repeated pattern images.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.

  In the embodiment of the present invention, the signature of the original image data is calculated and attached to the rendering command, the signature on the cache is checked against the attached signature, and if they match, the color conversion result on the cache is obtained and It is a printing system that reuses.

  FIG. 1 is a configuration diagram of a printing system according to an embodiment of the present invention. The printing system includes a host computer, a printing apparatus, and a host I / F that connects the two. In FIG. 1, the host computer includes a CPU 1, a memory 2, a cache 3, an application program 4, a print target data file 5, and a printer driver 20. The printing apparatus includes a CPU 41, a memory 42, a cache 43, a print processing program 44, and a PDL interpreter 50.

  FIG. 2 is a diagram illustrating the relationship between the PDL command and the print page image. FIG. 3 is a diagram illustrating the relationship between the PDL command and the image drawing command. FIG. 4 is a flowchart showing a processing procedure from generation to interpretation of a PDL command.

  The function and operation of the printing system in the embodiment of the present invention configured as described above will be described. First, an overview of the functions of the printing system will be described with reference to FIG. When the user prints the print target data file 5 opened by the application program 4, a drawing command and data are passed from the application program 4 to the printer driver 20, a PDL command is generated by the PDL command generation program 21, and the host I / O The PDL interpreter 50 processes it via F30.

  In the PDL interpreter 50, after the command is interpreted by the PDL command interpretation program 51, drawing is performed by the rendering program 52, and the result is processed by the print processing program 44 to obtain a print output. The color space of the data passed from the application program 4 is RGB, and the color space of the data received by the PDL interpreter 50 from the host I / F is also RGB, which is converted into the CMYK color space by the color conversion program 55 included in the rendering program 52. Is done.

  Before processing by the color conversion program 55, the signature held in the cache 43 is taken out, while the signature of the received data is created by the signature generation program 54 and the two signatures are compared. If they do not match, color conversion processing is performed by the color conversion program 55, and the signature and the color conversion result are cached. If they match, the color conversion result on the cache 43 is passed to the rendering program 52.

  Next, the relationship between the PDL command and the print page image will be described with reference to FIG. The PDL command on the left side is interpreted in order from top to bottom, and a print page image as shown on the right side is configured on the memory.

  Next, the relationship between the PDL command and the image drawing command will be described with reference to FIG. The image drawing command included in the PDL command is composed of parameters shown in the image drawing command (parameter) on the right side.

  Next, a flow from generation to interpretation of a PDL command will be described with reference to FIG. The command generation procedure shown in FIG. In step 1, RGB data is received from the application. In step 2, RGB image data compression processing is performed. In step 3, it is checked whether the data size has been reduced. If it is smaller, in step 4, the signature of the compressed data is calculated. If not, in step 5, the signature of the data before compression is calculated. In step 6, the signature of attribute information is calculated. In step 7, a signature, attribute information, and data body are generated in an image drawing command format.

  A command interpretation procedure shown in FIG. 4B will be described. In step 11, the signature, attribute information, and data body are extracted from the command. In step 12, it is checked whether the data is compressed. If the data is compressed, in step 13, the data body is decompressed. In step 14, the attribute information signature is compared with the cache. If they match, in step 15, the signature of the data body is compared with the cache. If they match, in step 16, the CMYK data after color conversion is acquired from the cache. If it does not match any of the signature caches, the signature of the attribute information is calculated and stored in the cache in step 17, the signature of the data body is calculated and stored in the cache in step 18, and the RGB in step 19 The data is converted into CMYK data, and in step 20, the converted CMYK data is stored in a cache. In step 21, the CMYK data is rendered into the drawing memory.

  As described above, in the embodiment of the present invention, the printing system calculates the signature of the original image data and attaches it to the drawing command. The signature on the cache is checked against the attached signature. Since the color conversion result is acquired and reused, the repeated pattern image can be printed at high speed.

  The printing system of the present invention is most suitable as a system for printing original data such as a watermark in which the background is filled with an image of a repeated pattern. It can also be applied to other image processing systems that require color conversion.

It is a block diagram of the printing system in the Example of this invention. FIG. 4 is a relationship diagram between a PDL command and a print page image of the printing system in the embodiment of the present invention. FIG. 5 is a relationship diagram between a PDL command and an image drawing command of the printing system in the embodiment of the present invention. 3 is a flowchart from generation to interpretation of a PDL command of the printing system in the embodiment of the present invention.

Explanation of symbols

1 ... CPU, 2 ... memory, 3 ... cache, 4 ... application program, 5 ... data file to be printed, 20 ... printer driver, 21 ... command generation program, 22 Rendering program, 23 ... Data compression program, 30 ... Host I / F, 40 ... Bus, 41 ... CPU, 42 ... Memory, 43 ... Cache, 44 ... Print processing 50 ... PDL interpreter 51 ... PDL command interpretation program 52 ... rendering program 53 ... data expansion program 54 ... signature generation program 55 ... color conversion program

Claims (14)

  Signature generating means for generating a signature that is unique digest data from original image data in the original color space, means for attaching the signature to a drawing command, a signature attached to the drawing command, and a signature on a cache memory A signature verification unit for verifying, a unit for acquiring corresponding drawing image data on the cache memory in response to a signature verification match, and a rendering image in the drawing color space for the original image data in accordance with a signature verification mismatch A drawing apparatus comprising: means for converting into image data and storing the converted drawing image data and the signature of the original image data in the cache memory.   In a printing system comprising a host computer and a printing device connected to the host computer, the printing device receives means for receiving original image data in a document color space from the host computer, and is unique from the original image data. Signature generating means for generating a signature that is digest data, means for compressing the original image data to generate compressed image data, means for attaching the signature to a drawing command, and a compressed image attached to the drawing command A means for decompressing data, a signature verification means for verifying a signature attached to the rendering command and a signature on the cache memory, and acquiring corresponding drawing image data on the cache memory in accordance with a match of the signature verification. And printing the original image data into drawing image data in the drawing color space according to the mismatch of signature verification Printing system comprising: a drawing image data Rutotomoni converting means for storing a signature of the original image data in the cache memory.   In a printing system comprising a host computer and a printing device connected to the host computer, the printing device receives original image data in a document color space from the host computer, and compresses the original image data Means for generating a signature that is unique digest data from the compressed original image data, means for attaching the signature to a drawing command, and means for decompressing the compressed image data attached to the drawing command Signature verification means for verifying a signature attached to the drawing command and a signature on the cache memory; means for acquiring and printing corresponding drawing image data on the cache memory in accordance with a match of the signature verification; The original image data is converted into drawing image data in the drawing color space and converted according to the mismatch of signature verification. Printing system comprising: a means for storing the the image for image data and signature of the original image data in the cache memory.   In a printing system comprising a host computer and a printing apparatus connected to the host computer, the host computer generates a signature that is unique digest data from original image data in a document color space, and Means for compressing original image data to generate compressed image data; and means for attaching the signature to a drawing command and transmitting the same to the printing device, the printing device receiving the drawing command from the host computer A means for decompressing the compressed image data attached to the drawing command, a signature checking means for checking the signature attached to the drawing command and the signature on the cache memory, and according to the match of the signature verification. Means for acquiring and printing the corresponding drawing image data on the cache memory, and the preceding in accordance with the mismatch of the signature verification; Printing system comprising: a means for storing the drawing image data converted and converts the drawing image data of the foreground color space and the signature of the original image data of the original image data in the cache memory.   In a drawing apparatus comprising a host computer and a printing apparatus connected to the host computer, the host computer compresses original image data in a document color space to generate compressed image data, and the compressed image data Signature generating means for generating a signature that is unique digest data from the image data, and means for attaching the signature to a drawing command and transmitting the signature to the printing device, the printing device receiving the drawing command from the host computer A means for decompressing the compressed image data attached to the drawing command, a signature checking means for checking the signature attached to the drawing command and the signature on the cache memory, and according to the match of the signature verification. Means for acquiring and printing the corresponding image data for drawing on the cache memory, and according to the mismatch of signature verification, Printing system comprising: a means for storing image forming data obtained by converting converts the image data to the image forming data of the foreground color space and the signature and the original image data in the cache memory.   In a printing system comprising a host computer and a printing apparatus connected to the host computer, the host computer generates a signature that is unique digest data from original image data in a document color space, and Means for compressing original image data to generate compressed image data; means for attaching the signature to a drawing command; means for decompressing compressed image data attached to the drawing command; and attached to the drawing command A signature collating unit for collating the signature with the signature on the cache memory, a unit for obtaining the corresponding drawing image data on the cache memory in accordance with a signature collation match, and the original image in accordance with a signature collation mismatch The data is converted into drawing image data in the drawing color space, and the converted drawing image data and the original image data And means for transmitting the drawing image data to the printing device, wherein the printing device receives the drawing image data from the host computer and prints the drawing image data. A printing system comprising:   In a drawing apparatus comprising a host computer and a printing apparatus connected to the host computer, the host computer compresses original image data in a document color space to generate compressed image data, and the compressed image data A signature generating means for generating a signature that is unique digest data, means for attaching the signature to a drawing command, means for decompressing compressed image data attached to the drawing command, and attached to the drawing command A signature collating unit for collating the signature with the signature on the cache memory, a unit for obtaining the corresponding drawing image data on the cache memory in accordance with a signature collation match, and the original image in accordance with a signature collation mismatch The data is converted into drawing image data in the drawing color space, and the converted drawing image data and the signature of the original image data In the cache memory; and means for transmitting the drawing image data to the printing apparatus, wherein the printing apparatus receives the drawing image data from the host computer and prints the drawing image data. A printing system comprising:   A signature, which is unique digest data, is generated from the original image data in the original color space, the signature is attached to the drawing command, the signature attached to the drawing command is compared with the signature on the cache memory, and signature verification is performed. The corresponding drawing image data on the cache memory is acquired according to the match, and the original image data is converted into the drawing image data of the drawing color space according to the signature verification mismatch, and the converted drawing image data A drawing method comprising storing the signature of the original image data in the cache memory.   The printing apparatus receives original image data in a document color space from a host computer, generates a signature that is unique digest data from the original image data, compresses the original image data, generates compressed image data, and A signature is attached to a drawing command, the compressed image data attached to the drawing command is decompressed, a signature attached to the drawing command is compared with a signature on a cache memory, and the cache is matched according to a signature verification match. The corresponding drawing image data on the memory is acquired and printed, and the original image data is converted into drawing image data in the drawing color space according to the mismatch of the signature verification, and the converted drawing image data and the original image A printing method comprising storing a data signature in the cache memory.   The printing apparatus receives original image data in the original color space from the host computer, compresses the original image data, generates a signature that is unique digest data from the compressed original image data, and attaches the signature to the drawing command And decompressing the compressed image data attached to the drawing command, collating the signature attached to the drawing command with the signature on the cache memory, and corresponding drawing on the cache memory according to a match of signature verification. The image data is acquired and printed, and the original image data is converted into drawing image data in the drawing color space according to the mismatch of the signature verification, and the converted drawing image data and the signature of the original image data are A printing method comprising storing in a cache memory.   A host computer generates a signature, which is unique digest data, from original image data in a document color space, compresses the original image data to generate compressed image data, and attaches the signature to a drawing command to a printing apparatus. And the printing apparatus receives the drawing command from the host computer, decompresses the compressed image data attached to the drawing command, and compares the signature attached to the drawing command with the signature on the cache memory In response to a signature verification match, the corresponding drawing image data on the cache memory is acquired and printed, and in response to a signature verification mismatch, the original image data is converted into a drawing color space drawing image data. A printing method comprising: storing the image data for drawing converted together with the signature of the original image data in the cache memory.   The host computer compresses the original image data in the original color space to generate compressed image data, generates a signature that is unique digest data from the compressed image data, and attaches the signature to a drawing command to the printing apparatus. And the printing apparatus receives the drawing command from the host computer, decompresses the compressed image data attached to the drawing command, and compares the signature attached to the drawing command with the signature on the cache memory In response to a signature verification match, the corresponding drawing image data on the cache memory is acquired and printed, and in response to a signature verification mismatch, the original image data is converted into a drawing color space drawing image data. A printing method comprising: storing the image data for drawing converted together with the signature of the original image data in the cache memory.   A host computer generates a signature, which is unique digest data, from original image data in the original color space, compresses the original image data to generate compressed image data, attaches the signature to a drawing command, The compressed image data attached to the image data is decompressed, the signature attached to the drawing command is collated with the signature on the cache memory, and the corresponding drawing image data on the cache memory is obtained in accordance with the signature collation match The original image data is converted into drawing image data in the drawing color space according to a signature verification mismatch, and the converted drawing image data and the signature of the original image data are stored in the cache memory, and the drawing Image data is transmitted to a printing apparatus, and the printing apparatus receives the image data for drawing from the host computer and prints it. Printing method.   A host computer compresses original image data in a document color space to generate compressed image data, generates a signature that is unique digest data from the compressed image data, attaches the signature to a drawing command, and The compressed image data attached to the image data is decompressed, the signature attached to the drawing command is collated with the signature on the cache memory, and the corresponding drawing image data on the cache memory is obtained in accordance with the signature collation match The original image data is converted into drawing image data in the drawing color space according to a signature verification mismatch, and the converted drawing image data and the signature of the original image data are stored in the cache memory, and the drawing Image data is transmitted to the printing apparatus, and the printing apparatus receives the drawing image data from the host computer and prints it. Printing method according to claim.

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