JP3423553B2 - Image processing apparatus and method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an m-value conversion process.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
For example, the binary image data from the page editing server 1 is printed as it is on the publication 3 as a color image of a single color multi-valued expression by using the printing device 2. When such a conventional printing method is applied to, for example, printing on a color paper surface in a newspaper printing process, a skilled worker must check the quality of the color paper surface immediately before printing, which is the final step of the printing process. C (cyan) version, M (magenta) finish
The four surfaces of the printing plate, the Y (yellow) printing plate, and the K (black) printing plate were individually printed in a single color, superimposed, and checked for defects such as color misregistration while visually comparing them.

[0003]

As described above, in the past, it has been the main practice to rely on humans for defects of color misregistration.

Further, when there are no skilled workers,
Even if there is a defect due to a lack of image data on the color paper surface, a large amount of defective paper surface may be printed as it is because the finish condition cannot be confirmed immediately before printing.

The present invention has been made in view of the above problems, and uses a simple image output method as compared with printing to determine the finish of a printed image in advance in a color image.
Both gradation and sharpness in achromatic images are maintained.
The purpose is to be able to check it while holding it .

Another object of the present invention is to be able to perform an m-value conversion process which shows the characteristics of the input image well.

[0007]

In order to achieve the above object, the present invention is characterized by having the following configuration.

A first invention of the present application is an image processing apparatus for performing image processing on image data composed of a plurality of color component data, wherein the plurality of color component data represented by n values are Used when performing m-value conversion processing according to the type of color component.
Based window size use the pixels included in the block of the setting means and the year set window size set for each color component, before the color component data of said n value
The color component types are yellow, magenta, cyan, and black, and the yellow, magenta, and cyan color component data are stored. from win <br/> Dousaizu use in m-value conversion process, the black color component data m Nekasho
It is characterized in that the window size used for processing is small.

A second aspect of the present invention is an image processing apparatus for performing image processing on image data composed of a plurality of color component data, which comprises the resolution of the image data and the image data.
Converting the plurality of color component data indicated by n values into m values
The correspondence of the window size used when processing ,
The storage means for storing each color component and the resolution of the input image data are discriminated, and the discrimination result is stored by the storage means.
The color component data is calculated based on the corresponding relationship
Window size to be used for colorization processing for each color component
Setting means for setting a, based on pixels included in the block of the set window size, the input image de
M- value conversion processing means for performing the m-value conversion processing (n <m) on the n-value color component data forming the data , and the types of the color components are yellow, magenta, cyan, and Black, and the color components of the yellow, magenta, and cyan components are
From the window size to use over data when m binarizing, using the black color component data when m binarizing
The feature is that the window size used is smaller.

[0010]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) Hereinafter, a case where the present invention is applied to a system for confirming a result of a color printing process by a simple color output device will be described with reference to the drawings.

FIG. 1 is a block diagram showing a system configuration according to this embodiment. This system has a print mode in which n publications are created using a known printing device 2 based on binary CMYK image data stored in the page editing server 1, and a simple electrophotographic color printer or the like. It has a trial printing mode in which a publication created by the printing apparatus 2 is confirmed in advance by using the image forming apparatus.

Binary CMYK image data input from the page editing server 1 is loaded into a binary multi-value conversion color image processing device 4 including an image processing device 30, a reading control device 40, and an image forming device 50. . The binary CMYK image data is converted into multi-valued RGB image data by the image processing device 30, output to the reading control device, and stored. The reading control device 40 outputs the stored RGB image data to the image forming device 50 in synchronization with the processing of the image forming device. In the image forming apparatus 50, the color conversion unit in the image forming apparatus performs color conversion according to the output characteristics of the printer to form the test printing color printing paper 5 based on the multivalued CMYK image data. The user confirms the finish condition with this test printing color printing paper 5.

If the finish of the test print paper 5 is good, color printing is performed by the printing device 2 based on the binary CMYK image data from the page editing server 1 to create the publication 3.

FIG. 2 shows the configuration of the binary / multi-value conversion color image processing device 4.

Reference numeral 11 denotes a central processing unit (CPU) in the form of a microprocessor, which controls each of the constituent elements described later and performs image output instruction control according to a procedure determined by a program stored in advance. A RAM 12 functions as a main memory and a work area of the CPU 11. A memory 13 stores image data indicating an image to be converted or an image after conversion. 14 is SCSI or G
Interface board such as PIB. Reference numeral 15 denotes a keyboard, on which character and symbol input keys for inputting document data, various keys for issuing an output instruction and a process stop instruction are arranged. Reference numeral 16 denotes a display device such as a display, which displays the contents input from the keyboard 5 and the contents of the converted image data. A floppy disk device 17 stores data such as program backup. A hard disk device 18 stores converted image data, programs, tables used for conversion, data such as an OS (operating system), and the like.

Reference numeral 19 is an interface board on the side of the reading control device. 20 is a read-only memory, which is a CPU 21
Is written with a program for controlling the scanner 23 and the printer 24. The CPU 21 is a central processing unit that controls the scanner 23 and the printer 24. 22
Is a memory that stores an image read from the scanner 23 or an image output to the printer 24, and can be expanded depending on the size of the image to be handled.

Reference numeral 23 is a scanner for scanning an original image,
Generate image data. Reference numeral 24 performs color conversion on the color image data and performs test printing.

Binary CMY from the page editing server 1 in FIG.
K image data is stored in the image memory 13 of FIG.
It is stored in the hard disk device 18 by the PU 11. Then, the binary CMYK image data is converted into multi-valued CMYK image data by the CPU 11 via the RAM 12.

The converted multi-valued CMYK image data is C
After being converted into multi-valued RGB data by the PU 11 and color-corrected as necessary, the scanner / image processor 30
It is stored in the image memory 22 via the printer interface and the scanner / printer interface of the read-out control section 40 of the processed image.

Multivalued RG stored in the image memory 22
The B image data is converted into multi-valued CMYK image data for printing by a color conversion unit inside the printer, and the printer 24
Will be output.

Next, the flow of the color image processing in the trial printing mode executed by the CPU 11 and the CPU 12 based on the program stored in advance in this embodiment will be described with reference to FIG.

First, in step S1, the page editing server 1
Binary CMYK image data is input and stored in the image memory 13. If the input binary CMYK image data has been compressed, in step S2 decompression processing is performed to restore the image.

In step S3, multi-value conversion processing for converting binary CMYK image data into multi-value CMYK image data is performed.

As shown in FIG. 4, for each color component data of C, M, and Y, the input image is divided into a plurality of blocks by a window of 8 * 8 pixels (see thick line in FIG. 4). Among the pixels included in the block, the number of pixels for which a bit is set is counted, and C, M, Y data indicated by 0-64 is created as output pixel data for each block. On the other hand, for the K component, the input pixel is 4 * 4
The pixel window is divided into a plurality of blocks (see double line in FIG. 4), and K color component data indicated by 0-16 is created.

As described above, since the input image is divided into a plurality of blocks by using different windows for the CMY color component and the K color component and the multi-value processing is performed, the gradation of the color image is maintained. It is possible to maintain the sharpness of an achromatic image such as a black character, and prevent moire in the output image. However, the resolutions of the CMY color component data and the K color component data after the multi-value processing are different.

In step S4, CMYK-RGB for converting multi-valued CMYK image data into multi-valued RGB image data.
Perform conversion processing.

First, in order to match the resolution of CMY color component data with the resolution of K color component data, resolution conversion is performed on the CMY color component data.

Then, the R color component data is generated from the multi-valued C color component data and the K color component data by using the following conversion formula.

R = 255- (C + K) Similarly, the G and B color component data is generated using the conversion formula shown below.

G = 255- (M + K) B = 255- (Y + K)

In this way, by interlocking the multi-valued processing in step S3 and the CMYK-RGB conversion processing in step S4, good reproduction in trial printing color printing is realized.

In step 5, color correction is performed on multi-valued RGB image data by using a masking coefficient and a gamma table prepared in advance for the printing apparatus 2.

Since the purpose of the system shown in the present embodiment is to detect a defect in a publication such as a color shift, if the faithful color reproduction is not emphasized, the step S is performed.
It is also possible to omit 5.

In step S6, color-corrected multivalued RGB
The image data is output to the image forming apparatus 50, and the test printing color printing paper 5 is formed.

According to the present embodiment, it is possible to prevent moire on the test printing color printing paper, and it is possible to confirm defects in the publication with high accuracy using the test printing color printing paper.

(Embodiment 2) In Embodiment 2, a system used for test printing an output image composed of a plurality of object images having different characteristics will be described.

The basic configuration of the system is the same as that of the first embodiment.
The description of the same parts as those of the first embodiment will be omitted.

The output image composed of a plurality of object images having different characteristics is, for example, an output image composed of objects of a photographic image 60 and a character image 61 having different resolutions as shown in FIG.

The flow of processing in the trial printing mode in the system according to the second embodiment will be described below with reference to FIG.

In step S1, image information indicating an object described in the format shown in FIG. 6 is input. The image information includes position information indicating the position of the object in the output image, size information indicating the size of the image data, resolution information indicating the resolution of the image data, and binary Y.
It is composed of MCK image data.

In step S11, the defrosting process is performed as in step S2 of the first embodiment.

In step S12, the resolution of the object is determined based on the resolution information included in the image information.

In step S13, the multi-value quantization processing mode and CMYK-RGB corresponding to the resolution determined in step S12 are set.
Set the conversion processing mode.

In order to prevent the appearance of moire in the output image, it is necessary to set a window according to the resolution of the object. Therefore, in the second embodiment, the correspondence relationship between each of the plurality of resolutions and the window size is stored in advance, and the window size according to the resolution of the object is set in the multi-value quantization process. Further, the resolution conversion processing according to the window size is set to CMYK-RGB conversion processing.

In step S14, a multi-value conversion process for converting binary CMYK image data into multi-value CMYK image data is performed according to the window size set in step S13 as in step S3 of the first embodiment.

In step S15, resolution conversion processing is performed in accordance with the window size set in step S13, and CMYK-RG is performed as in step S4 of the first embodiment.
B conversion processing is performed.

In step S16, color correction is performed in the same manner as in step S5 of the first embodiment, and in step 17, the position information and size information described above are added to the color-corrected multi-valued RGB data to indicate an object. Read control device 4 as information
Output to 0.

The above steps S1 to S16 are sequentially performed on each of the plurality of objects forming the output image.

Next, the reading control device 40 will be described with reference to FIG.
The flow of processing in the above will be described.

First, in step S18, image information indicating a plurality of objects forming an output image is input.

In step S19, position information is extracted from the header information of the image information indicating each object, and the position of each object in the output image is determined.

In step S20, each object is combined based on the position determined in step S19, and multivalued RGB image data showing the entire output image is generated.

In step S21, multivalued RGB image data representing the entire output image is raster-formatted by the image forming apparatus 50.
The output image is output in synchronism with the above process to form a trial printing color printing paper 5 of the output image.

According to the second embodiment, it is possible to perform a process suitable for each of a plurality of objects having different resolutions, and it is possible to form a good trial color printing paper without moire.

Therefore, a defect such as a color shift in the publication can be confirmed with high accuracy by the test printing color printing paper.

(Other Embodiments) The present invention is not limited to the conversion from a binary value to a multivalued one byte, but may be an n value to an m value (n <m). .

Further, the output to the image forming apparatus is not limited to the RGB image data, and CMYK image data or another color format may be used. For other color formats, processing after resolution conversion
May be changed according to the color format.

Further, the present invention is applied to a system composed of a plurality of devices (eg, host computer, interface device, reader, printer, etc.), but is also applied to a device composed of one device (eg, copying machine, facsimile machine). You may.

Further, software for realizing the functions of the above-described embodiments is provided to a computer in an apparatus or system connected to the various devices so as to operate the various devices so as to realize the functions of the above-described embodiments. It is also within the scope of the present invention to implement the program by supplying the program code and causing the computer (CPU or MPU) of the system or apparatus to operate the various devices according to the stored program.

Further, in this case, the program code itself of the software realizes the function of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, for example, such program code. The storage medium storing the above constitutes the present invention.

A floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a non-volatile memory card, a ROM or the like can be used as a storage medium for storing the program code.

Further, not only the functions of the above-described embodiments are realized by executing the supplied program code by the computer, but also the OS (operating system) in which the program code is operating in the computer, or other Needless to say, the program code is also included in the embodiments of the present invention when the functions of the above-described embodiments are realized in cooperation with application software or the like.

Further, the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, and then stored in the function expansion board or the function storage unit based on the instruction of the program code. It goes without saying that the present invention also includes a case where the provided CPU or the like performs a part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

[0064]

As described above, according to the present invention,
Using a simple image output method compared to printing, the finish of the printed image can be adjusted in advance with the gradation of color images and achromaticity.
This can be confirmed while maintaining both the sharpness of the color image .

Further, it is possible to perform the m-value conversion process which shows the characteristics of the input image well.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a system according to an embodiment of the present application.

FIG. 2 is a block diagram showing a configuration of a binary multi-value conversion color image processing device according to the embodiment of the present application.

FIG. 3 is a flowchart showing a flow of processing according to the first embodiment.

FIG. 4 is a diagram illustrating a window size used for multi-value quantization processing.

FIG. 5 is a diagram showing an example of an output image according to the second embodiment.

FIG. 6 is a diagram showing a format of image information of an object according to the second embodiment.

FIG. 7 is a flowchart showing a flow of processing performed by the image processing apparatus according to the second embodiment.

FIG. 8 is a flowchart showing a flow of processing performed by the reading control device according to the second embodiment.

FIG. 9 is a diagram showing a conventional printing process.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masahiro Masahiro 3-11-28 Mita, Minato-ku, Tokyo Canon Sales Co., Ltd. (56) Reference JP-A-9-149242 (JP, A) JP-A-3 −88578 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/60 G06T 5/00 100 H04N 1/46

Claims (10)

(57) [Claims] 1. An image processing apparatus for performing image processing on image data composed of a plurality of color component data, wherein:
Based on the setting means for setting the window size to be used when performing the m-value conversion process according to the type of color component for each color component and the pixels included in the block of the window size set in the previous period, wherein m for the color component data of n values
M value conversion processing means for performing a value conversion process (n <m), the types of the color components are yellow, magenta, cyan, and black, and the yellow, magenta, and cyan color component data are m values. Conversion
Than the window size to be used in processing, the image processing apparatus characterized by Wynn <br/> Dousaizu small to use the bra <br/> click color component data when m-value process. 2. The image data is data to be output to a printing device for creating a printed matter, and the m-valued plurality of color component data is used to confirm in advance the printed matter created by the printing apparatus. The image processing apparatus according to claim 1, wherein the image is output to an image forming apparatus different from the printing apparatus. 3. The image processing apparatus according to claim 1, wherein the n value is binary. 4. An image processing apparatus for performing image processing on image data composed of a plurality of color component data , comprising: a resolution of the image data and an n value forming the image data.
M-value-processing the plurality of color component data shown
For the correspondence of the window size used for each color component
Storage means for storing the bets, to determine the resolution of the input image data,該判Results by said skeleton
Based on said correspondence stored by paying means, said
Setting means for setting the window size to be used when the color component data is subjected to the m-value conversion process for each color component, and included in the block of the set window size.
Based on the pixel, performs the m-valued processing on the color component data of n values constituting the input image data (n <m) m
The color component types are yellow, magenta, cyan, and black, and the yellow, magenta, and cyan color component data are converted into m-values.
Than the window size to be used in processing, the image processing apparatus, characterized in that towards the win <br/> Dousaizu small to be used to the bra <br/> click the color component data m-valued processing. 5. The image processing apparatus according to claim 4 , wherein the discrimination means discriminates the resolution of each of the plurality of objects constituting the input image data and sets the window size. 6. An image processing method for performing image processing on image data composed of a plurality of color component data, the method comprising:
The window size used when performing the m-value conversion process according to the type of color component is set for each color component, and the n value is determined based on the pixels included in the block of the set window size. wherein m respect of color component data
An image processing method for performing a binarization process (n <m), wherein the types of color components are yellow, magenta, cyan, and black, and the yellow, magenta, and cyan color component data are m-valued.
Than the window size to be used in processing, image processing method, wherein a win <br/> Dousaizu small to use the bra <br/> click color component data when m-value process. 7. The image data is data to be output to a printing apparatus for creating a printed matter, and the m-valued plurality of color component data confirms in advance the printed matter created by the printing apparatus. 7. The image processing method according to claim 6, wherein the image is output to an image forming apparatus different from the printing apparatus. 8. The image processing method according to claim 6, wherein the n value is binary. 9. An image processing method for performing image processing on image data composed of a plurality of color component data , comprising: a resolution of image data and an n value forming the image data.
M-value-processing the plurality of color component data shown
For the correspondence of the window size used for each color component
And the resolution of the input image data is discriminated, and the discrimination result and the case
Based on said correspondence stored by paying means, said
A window size used when the color component data is converted into an m-value is set for each color component and included in the block having the set window size.
Based on the pixel is the m-value process (n <m) image processing method for performing the color component data of n values constituting the input image data, the kind of the color components of yellow, magenta, cyan , And black, and the yellow, magenta, and cyan color component data are converted into m-values.
Than the window size to be used in processing, image processing method, characterized in that towards the win <br/> Dousaizu small to be used to the bra <br/> click the color component data m-valued processing. 10. The image processing method according to claim 9, wherein the determination is performed by determining the resolution of each of a plurality of objects forming the input image data.