JP2003283855A - Picture processor, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a picture processor for correctly performing an ROP processing to printing data, and generating printing data at high speed without deteriorating color. <P>SOLUTION: The picture processor generates binary CMYK color printing data from multilevel color picture data. The processor includes: a color correcting means 22 for converting the color of multilevel color picture data into that of a device depending CMY data, and obtaining picture data which are corrected in density; a binary processing means 23 for performing a binary processing with respect to picture data which are corrected by the color correcting means 22; a gray area deciding means 24 for calculating a gray area where black has to be generated, based on each kind of CMY data obtained by the binary processing means 23; a plotting means 25 for performing a plotting processing in each CMY data obtained by the binary processing means 23; and a black generating means 26 for generating black in the gray area which is decided by the gray area deciding means 24, based on each CMY data obtained by the plotting means 25. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing device, a program and a recording medium, and more specifically, a multi-valued C
Binary CMYK according to output device characteristics from MY data
The image processing technique for generating data is suitable for application to a printing device such as a color digital copying machine or a color printer.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, a color image is converted into CMYK data corresponding to cyan (C), yellow (Y), magenta (M) and black (K) and printed. There is. On the other hand, Windows (registered trademark) GDI (Graphical Display)
A printer that draws images based on the interface needs to have a function called ROP processing (Raster Operation).

In this ROP process, each color has an independent R
Can be correctly performed on GB data or CMY data, but CMY generated based on CMY data
Since K (black) in K data depends on CMY data, a desired processing result may not be obtained when ROP processing is performed on CMYK data. Therefore, the RG created by the application program
In order to realize the function of the ROP process when printing B data, R data in the form of RGB data or CMY data is converted before conversion of RGB data into CMYK data.
OP processing must be performed. Further, after the ROP processing, a desired tint cannot be obtained by simply replacing the point where the C, M and Y components of the CMY data overlap with K (black).

[0004]

With respect to such a problem, in the "image processing device" of Japanese Patent Laid-Open No. 11-164164, RGB image data is converted into CMY data, and the data is converted into CMY data. ROP processing is performed. This ROP
The processed CMY data is binarized, the black density of the binary CYM data is detected, and B is calculated based on the detected density.
Generate a G / UCR pattern and use this pattern to
MYK color print data is generated. This allows a printer that prints according to CMYK data to
The ROP processed data can be supplied.

However, in the technique disclosed in Japanese Unexamined Patent Publication No. 11-164164, the ROP processing is performed with multi-valued CMY data, and this processing requires a large amount of time and memory.

Further, in "Image processing apparatus and image processing method" of Japanese Patent Laid-Open No. 2000-341547, RGB image data is converted into CMY data, and ROP processing is applied to the data. The ROP-processed CMY data is binarized, black generation and undercolor removal processing is performed on the binarized CMY data, and then density correction processing according to the characteristics of the printer is performed on the binary CMYK data. Done,
The corrected binary CMYK data is output. Since density correction is performed after black generation and undercolor removal processing,
The black generation and the undercolor removal processing are not affected by the characteristics of the output target printer.

However, in the technique disclosed in Japanese Unexamined Patent Publication No. 2000-341547, the ROP process is performed with multi-valued CMY data as in the technique disclosed in Japanese Unexamined Patent Publication No. 11-164164.
It takes a lot of time and memory to process.

The present invention has been made in consideration of the above-mentioned circumstances, and the ROP process can be accurately performed on print data, and the ROP process can be performed according to the characteristics of the output device without impairing the tint. An object of the present invention is to provide an image processing device that generates CMYK data from CMY data at high speed, a program for executing the functions of the image processing device, and a computer-readable recording medium that records the program.

[0009]

In order to solve the above-mentioned problems, an image processing apparatus according to claim 1 of the present invention is an image processing apparatus for generating binary CMYK color print data from multi-valued color image data. In the above, the multivalued color image data is color-converted into device-dependent CMY data to obtain density-corrected image data, and binarization processing is performed on the image data corrected by the color correction unit. Binarization processing means to perform, gray area determination means for calculating a gray area for black generation based on each CMY data obtained by the binarization processing means, and each C obtained by the binarization processing means.
And a black generating unit for generating black in the gray region determined by the gray region determining unit based on each CMY data obtained by the drawing unit. Characterize.

According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the black generation means is CMY3 within the gray area obtained by the gray area determination means.
The gray value G is calculated from the logical sum of binary data of colors, the primary gray value G1 is calculated from this gray value G, the secondary gray value G2 is calculated from this primary gray value G1, and the gray value G is calculated.
The gray value G3 of the boundary portion is calculated from
OR result of the gray value G3 and the gray value G
It is characterized in that it is generated by obtaining a black color by AND operation with.

According to a third aspect of the present invention, in the image processing apparatus according to the second aspect, the gray value G is set with 32 bits in the main scanning direction and 4 lines in the sub scanning direction as one block.
With that block, for all separated blocks

[0012]

[Equation 2]

According to a fourth aspect of the present invention, in the image processing apparatus according to the second or third aspect, the gray value G1 is obtained.
All 32 bit units and pattern 2 ({0x5555555
5}) and the result of the AND operation as GC, and all 32 bit units of the gray value G1 and the pattern 3 ({0xaaaaa
and the gray value G2 is the result of the AND operation of the GC and the result of logically shifting the GA by 1 bit to the right for each line.

Further, claim 5 of the present invention includes claims 2, 3
Or the gray value G3 of the boundary portion is ANDed with a result of logically shifting the gray value G by 2 bits to the left for each line and the gray value G.
It is characterized in that the operation result, the result of logically shifting the gray value G by 2 bits to the right for each line, and the AND operation result of the gray value G are used as the result of the OR operation.

The program according to claim 6 of the present invention is
It is a program for causing a computer to function as the image processing device according to any one of claims 1 to 5. A recording medium according to claim 7 of the present invention is a computer-readable recording medium recording the program according to claim 6.

With the above-described configuration, a mask is applied so that the overlapping components of the C, M, and Y components are gradually replaced with K (black) without simply replacing the overlapping of the colors of CMY data with K (black). By substituting it, black color can be generated without impairing the tint. Also, ROP
Since the processing is performed on the binarized CMY data,
Accurate ROP processing can be performed. In addition, 2
Since the black color is generated from the binarized CMY data, it is possible to generate the print data that does not impair the tint. Further, a candidate for a region for which black generation is to be performed (gray region) is determined from the binarized CMY data, and black generation is performed only for this gray region, so high-speed calculation can be performed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an image processing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example in which the image processing apparatus of the present invention is installed in a printer device as a printer controller. In FIG. 1, this embodiment shows a printer device 10.
The host computer 30 and the host computer 30 are connected by an interface such as a parallel port or a serial port (USB, IEEE1394, etc.). This printer device 10
It is composed of an I / F control unit 11, an image processing device (printer controller) 20, and an image forming engine 12. Further, the image processing device (printer controller) 20 is
DL interpretation means 21, color correction means 22, binarization processing means 2
3, gray area determination means 24, drawing means 25, and black generation means 26.

The host computer 30 supplies a PDL command described in the printer description language (PDL) as drawing data in the RGB color space to the printer device 10.
The printer device 10 uses the P from the host computer 30.
The DL command is input to the image processing apparatus (printer controller) 20 via the I / F control unit 11, subjected to predetermined image processing, and then output to the image forming engine 12 to obtain a color image.

The image processing apparatus 20 includes an I / F control means 11
The PDL command received in step 1 is interpreted by the PDL interpreting means 21 and expanded into an intermediate language (display list), and this intermediate language is expanded into drawing data in the RGB color space. This is a convenient format for expanding in band units,
Multiple interpreters (eg PCL (PrinterCo
control language (Language) and PS (PostSc)
(i.e., "ript) etc.", the code size of the renderer (expansion unit) can be suppressed and development can be efficiently performed by dropping the intermediate language common to the languages.

The color correction means 22 color-matches the drawing data in the RGB color space to perform device-dependent CMY.
The color conversion is performed on the drawing data in the color space, the gamma correction is performed on the drawing data, and the density of the image is corrected so as to be faithfully reproduced according to the device.

The binarization processing means 23 binarizes the multi-valued CMY data output from the color correction means 22 by a dither matrix corresponding to each color, and performs binarization processing corresponding to each color for one page. Output the binarized data to the memory. At this time, the output memories of the respective colors are referred to as C plane, M plane, and Y plane, respectively.

The gray area determining means 24 performs an AND operation on each plane and stores the gray area in the memory (K plane) as a candidate area for generating black. this is,
Even when trying to discriminate the gray area of multi-valued data, it is not known whether it will eventually become gray when binarized.
The gray area is judged after binarization.

The drawing means 25 is used by the binarization processing means 23.
P for each binarized CMY color (per plane)
ROP processing such as AND operation and OR operation of CMY data is performed according to the instruction content included in the DL command. CMY
ROP processing is performed by CMYK (4 Color
When ROP processing is performed in Model, RGB (3 Col
or) The compatibility with the ROP processing of the model may not be maintained in some cases.

The black generating means 26 is the RO of the drawing means 25.
K (black) is generated from the P-processed CMY color space data. Here, K (black) is generated at high speed from CMY data that has fallen to 1 bit without losing the tint. The meaning of masking with the calculation shown below is that if you simply replace all of the C, M, and Y component overlaps with K (black), the tint will be greatly impaired. K is the overlapping component of CMY
By replacing with (black), black can be generated without impairing the tint.

FIG. 2 is a flow chart for explaining the processing procedure when performing black generation. First, an AND operation is performed on the C plane, M plane, and Y plane, which store binary data of three colors, to calculate a gray value, and the calculation result is stored in a memory (hereinafter, referred to as G) (step S
1). For the memory of this gray value G, the main scanning direction 3
2 bits, 4 lines in the sub-scanning direction are divided as one block (see FIG. 3), and the result of mask operation (AND operation) with pattern 1 is stored in a memory (hereinafter referred to as G1) for all the divided blocks. Yes (Step S
2). Here, the primary gray value G1 for calculating the final gray value in the gray area is calculated. Here, as the pattern 1, a pattern represented by the following hexadecimal number (prefixed with 0x) is used.

[0026]

[Equation 3]

The above calculation is performed in the main scanning direction 3 as shown in FIG.
2 bits, 4 lines in the sub-scanning direction are divided into one block (in FIG. 3, blocks A1, A2, ..., An, B
, B2, ..., Bn, ...). The divided block and the pattern 1 and the result of the mask calculation are stored in the same block position of the memory (G1), and the same mask calculation is performed while shifting the next mask target block by one block in the main scanning direction. When it reaches the last block in the main scanning direction, it is shifted in the sub-scanning direction, the above calculation is performed, and the operation is continued until the last block in the memory G is reached.

Next, the calculated memory G1 is divided into 32-bit units for each line, and the following calculation is performed for all units and stored in the memory (hereinafter referred to as G2) (step S3). ((G1 32-bit unit) ∧ Pattern 2)) ∧ (((G1 32-bit unit) ∧ Pattern 3) logically right-shifted by 1 bit) Here, pattern 2 and pattern 3 are the following hexadecimal numbers. (0x
Prefixed in) is used. Further, ∧ means a mask operation (AND operation). Pattern 2 = {0x55555555} Pattern 3 = {0xaaaaaaaa} Here, the secondary gray value G2 for obtaining the final gray value in the gray area is calculated.

In the above calculation, the memory (G1) is divided into 32-bit units for each line, and the AND operation of the two patterns 2 and 3 is performed for each 32-bit unit. Of these, the logical shift is performed to the right by 1 bit for the entire line obtained by ANDing the pattern 3. The result of the AND operation of these two results (the AND operation result with pattern 2 and the result of right-shifting by 1 bit) becomes the secondary gray value G2 for one line. By repeating this up to the last line of the memory (G1), the secondary gray value G2 is obtained.

Next, the memory (G) is line by line,
(G ∧ (Result of logically shifting G to the left by 2 bits)) ∨
(G∧ (the result of logically shifting G to the right by 2 bits)) is calculated and stored in the memory (hereinafter referred to as G3) (step S4). Here, ∨ means an OR operation. This is to prevent the loss of gray at the boundary of the gray area.

The memory (G, G2,
The following calculation is performed from G3) and the gray area (K plane) to generate K (black) (step S5). K = G∧ (G2∨G3∨K)

Further, since the AND operation with the K plane is finally performed from the above equation, a portion where a bit is set in the K plane (a portion where the same position of CMY after binarization becomes 1 is 1). , The calculation process can be minimized by applying the above-mentioned processing steps only to a place where the color can be black even after the ROP process.

Next, the operation of the image processing apparatus having the above configuration will be described. FIG. 4 is a flow chart for explaining the processing procedure of the image processing apparatus of the present invention. The I / F control means 11 of the printer device 10 receives the PDL command sent from the host computer 30, interprets this PDL command, develops it into an intermediate language (display list), and from this intermediate language to the RGB color space. To the drawing data (step S11).

Color matching is performed on the drawing data in the RGB color space to perform color conversion into drawing data in the device-dependent CMY color space (step S12). Gamma correction is performed on the color-converted drawing data to correct the density of the image so as to faithfully reproduce it according to the device (step S13).

The density-corrected CMY data is binarized by multiplying it by the dither matrix corresponding to each color, and the binarized data corresponding to each color for one page is output to the memory (step S14). At this time, the output memories of the respective colors are referred to as C plane, M plane, and Y plane, respectively.

An AND operation of each plane is performed and the result is stored in the memory (K plane) (step S15). In advance
K from the data of the CMY color space that has been density-corrected and binarized
Find the area (gray area) that seems to be (black),
When black is generated, black is generated only for this gray area to ensure high calculation speed.

For each color of the binarized CMY calculated above (for each plane), ROP processing such as AND operation or OR operation of CMY data is performed according to the instruction content included in the PDL command (step S16).

K (black) is generated from the ROP-processed CMY color space data by the process described in FIG. 2 (step S17). Finally, the image forming engine 1 generates the CMYK drawing data consisting of the CMY and the generated K up to now.
2 to obtain a color image.

Furthermore, the present invention is not limited to the above embodiment. FIG. 5 is a block diagram showing the configuration of a general-purpose computer system for implementing the image processing apparatus of the present invention. In FIG. 5, a central processing unit (CPU) 41, an input device 42 such as a keyboard, a mouse or a touch panel, and a display device 4 such as a display.
3, an output device 44 such as a printer, a memory 45, a storage device 46 such as a hard disk, and a medium reading device 47.
And are connected by a data bus 48. The program code for executing the functions of the above-described embodiment of the image processing apparatus is recorded in a recording medium, the program code recorded in the recording medium is read from the medium reading device 47 or the storage device 46, and the computer shown in FIG. The present invention can be easily implemented by installing the program on the CPU 41 and executing the program on the CPU 41. In this case, the program code itself read from the recording medium also realizes the functions of the above-described embodiments, and the program code and the recording medium storing the code constitute the present invention.

The recording medium is a semiconductor medium (eg, ROM, non-volatile memory card, etc.), optical medium (eg, DVD, MO, MD, CD-R, etc.), magnetic medium (eg, magnetic tape, flexible disk). Etc.) and the like.

Further, not only the function of the above-described embodiment is realized by executing the loaded program, but also the operating system or the like performs a part or all of the actual processing based on the instruction of the program, and It also includes the case where the functions of the above-described embodiments are realized by the processing.

Further, the program code for executing the functions of the above-described embodiments is loaded into the memory provided in the function expansion board or the function expansion unit, and the CPU provided in the function expansion board or the function expansion unit based on the instruction of the program. Include the case where some or all of the actual processing is performed and the processing realizes the functions of the above-described embodiments.

When the above-mentioned program is stored in a storage device such as a magnetic disk of a server computer and is distributed in a format such as download from a user's computer connected by a communication network such as the Internet, the program of the server computer A storage device is also included in the recording medium of the present invention.

[0044]

As described above, according to the present invention, the components of the CMY data which are overlapped little by little by K (black) are not replaced by simply replacing the overlap of the colors of CMY data by K (black). By replacing it with (black), black can be generated without impairing the tint. Further, since the ROP processing is performed on the binarized CMY data, accurate ROP processing can be performed. In addition, since the black color is generated from the CMY data that has been binarized by performing the density correction, it is possible to generate print data that does not impair the tint. Further, a candidate for a region for which black generation is to be performed (gray region) is determined from the binarized CMY data, and black generation is performed only for this gray region, so high-speed calculation can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration when an image processing apparatus of the present invention is attached to a printer device.

FIG. 2 is a flowchart for explaining a processing procedure when performing black generation.

FIG. 3 is a diagram for explaining the order in which pattern 1 is applied.

FIG. 4 is a flowchart for explaining a processing procedure of the image processing apparatus of the present invention.

FIG. 5 is a block diagram showing a hardware configuration when the image processing apparatus of the present invention is implemented by a general-purpose computer system.

[Explanation of symbols]

10 ... Printer device, 11 ... I / F control means, 12 ... Image forming engine, 20 ... Image processing device, 21 ... PDL interpreting means, 22 ... Color correction means, 23 ... Binarization processing means, 24 ...
Gray area determination means, 25 ... Drawing means, 26 ... Black generation means, 30 ... Host computer, 41 ... CPU, 42 ...
Input device, 43 ... Display device, 44 ... Output device, 45 ... Memory, 46 ... Storage device, 47 ... Medium reading device, 48 ... Data bus.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C262 AA24 AB19 AC02 BA02 BA07                       BA09 EA04 EA08                 5B057 AA11 CA01 CA08 CA12 CA16                       CB01 CB08 CB12 CB16 CC01                       CE17 CE18 CH07 CH08                 5C077 LL19 MP08 NN08 PP32 PP33                       PP37 PP38 PP48 PP68 PQ12                       TT02                 5C079 HB01 HB03 HB12 LA21 LB02                       LC04 MA11 NA11 PA03

Claims (7)

[Claims] 1. A binary CM from multivalued color image data
In an image processing apparatus for generating YK color print data, the multivalued color image data is converted into a device-dependent CM.
Color correction means for color-converting Y data to obtain density-corrected image data, binarization processing means for performing binarization processing on the image data corrected by the color correction means, and the binarization processing A gray area determination means for calculating a gray area for black generation based on each CMY data obtained by the means; a drawing means for performing a drawing processing on each CMY data obtained by the binarization processing means; An image processing apparatus comprising: a black generation unit that generates black in the gray area determined by the gray area determination unit based on each CMY data obtained by the drawing unit. 2. The image processing device according to claim 1, wherein the black generation unit calculates a gray value G from a logical sum of binary data of three colors of CMY within the gray region obtained by the gray region determination unit. Then, the primary gray value G1 is calculated from the gray value G, the secondary gray value G2 is calculated from the primary gray value G1, and the gray value G at the boundary portion is calculated from the gray value G.
The image processing apparatus is characterized by calculating 3 and calculating a black value by an AND operation of the OR value of the gray value G2 and the gray value G3 and the gray value G. 3. The image processing apparatus according to claim 2, wherein 32 bits in the main scanning direction and 4 lines in the sub scanning direction are set as one block, and the gray value G is divided by the block, and all the blocks are divided. [Equation 1] An image processing apparatus, wherein the gray value G1 is the result of an AND operation using the. 4. The image processing device according to claim 2, wherein the result of ANDing all 32-bit units of the gray value G1 and the pattern 2 ({0x55555555}) is GC, and the gray value G1. The result of ANDing all 32 bit units of and the pattern 3 ({0xaaaaaaaa}) is set as GA, and the gray value G2 is obtained by ANDing the result of logically shifting the GA by 1 bit to the right and the GC. An image processing apparatus, which is a calculation result. 5. The image processing apparatus according to claim 2, 3 or 4, wherein the gray value G3 of the boundary portion is the result of logically shifting the gray value G by 2 bits to the left for each line and the gray value G. And an AND operation result of the gray value G logically shifted by 2 bits to the right for each line, and an AND operation result of the gray value G. 6. A program for causing a computer to function as the image processing apparatus according to claim 1. 7. A computer-readable recording medium on which the program according to claim 6 is recorded.