JP2006237681A - Color image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To print beautiful image data with no strange feeling by creating optimal black data for every writing object. <P>SOLUTION: The color image processor for processing color image data including a plurality of color components comprises a first black creation means for creating first black data in correspondence with the type of a writing object from first inputted color image data, a logical operation means for creating second color image data by performing logical operation based on the first color image data, and a second black creation means for creating second black data from the second color image data on the basis of the first black data created by the first black creation means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color image processing apparatus that performs processing on color image data including a plurality of color components such as cyan, magenta, and yellow.

  2. Description of the Related Art Conventionally, a color printer uses image data for each color component of cyan (C), magenta (M), and yellow (Y) converted from data expressed in a so-called RGB format as upper-level data such as an application program or a host computer. Based on the image data received from the apparatus, a predetermined multi-valued logical operation is performed on CMY three-color data, and black (K) data is generated based on the generated data.

  As described above, when processing is performed on color image data, the processing is performed on the basis of CMY three-color data. As a technique related to such color image processing, for example, a technique described in Patent Document 1 is proposed.

JP-A-5-276368

  Specifically, Patent Document 1 discloses a color image processing method for converting a luminance image signal into a corresponding density image signal. In particular, in this color image processing method, in the halftone density area, the under color removal and the blackening amount are increased, and in the high density area, the under color removal is reduced and converted into a corresponding density image signal. As a result, in this color image processing method, gray uniformity can be compensated.

  By the way, in the conventional color image processing technique, the mixed color black and the monochrome black based on the CMY three-color plane data are logically the same. However, in the conventional color image processing technique, as described above, the black data is generated for the final data after the logical operation, so that the optimum black data for each drawing object existing in the image data. Could not be generated. For example, let us consider a case where a sunset that is gradation black toward the end of an image is depicted. In the conventional color image processing technology, when drawing such a sunset, the mixed color black based on the plane data of the CMY three colors is replaced with a normal single color black at a certain level. Therefore, image data that is left uncomfortable is generated.

  The present invention has been made in view of such circumstances, and generates optimal black data for each drawing object for data after logical operation, and enables printing of beautiful image data without a sense of incongruity. An object is to provide a color image processing apparatus.

  A color image processing apparatus according to the present invention that achieves the above-described object is a color image processing apparatus that performs processing on color image data including a plurality of color components, and is based on input first color image data. First black generating means for generating first black data corresponding to the type of drawing object, and logical operation for performing logical operation based on the first color image data and generating second color image data And second black generation means for generating the second black data from the second color image data based on the first black data generated by the first black generation means. It is characterized by that.

  In such a color image processing apparatus according to the present invention, black generation is not performed for the entire page obtained by the logical operation, but black generation is performed before the logical operation. The black component can be generated under various conditions. That is, in the color image processing apparatus according to the present invention, the black generation method can be changed for each type of drawing object.

  Here, as the first color image data, data including each color component of cyan, magenta, and yellow can be applied.

  The first black generation means compares the black data generated from each of the pattern, source, and destination of the first color image data, and the one having the maximum gradation value is the first black image data. Mixed color black determination processing means for determining black data.

  Further, the second black generation means is generated by a post-logical operation black generation means for generating black data after a logical operation based on the second color image data, and the post-logical operation black generation means. Third black generation means for generating the second black data based on the black data and the first black data before the logical operation generated by the first black generation means; The third black generation means calculates the gradation value to be left as the second black data, with the gradation value of the first black data as an upper limit. At this time, when the gradation value of the first black data is larger than the gradation value of the second black data, the second black generation means sets the monochrome black.

  Then, the second black generating means compares the black data generated after the logical operation with the first black data for each pixel, and leaves the data having a small gradation value, thereby remaining as black data. Power gradation data is generated, and the second black data is generated by subtracting the gradation data for each pixel from the black data. The second black generation means subtracts the gradation data from the mixed color black data after the logical operation, and subtracts the result from the gradation values of the other colors to generate data of other colors.

  The color image processing apparatus according to the present invention further includes gradation conversion means for converting the number of gradations of the second color image data. Thereby, in the color image processing apparatus according to the present invention, after the logical operation, the second color image data can be set to the number of gradations that can be expressed by the printing apparatus. Therefore, in the color image processing apparatus according to the present invention, it is possible to design a logical operation means that is unaware of the number of gradations that can be expressed by the printing apparatus.

  The first color image data is preferably data obtained by performing color matching on color image data expressed in RGB format and converting it to color image data expressed in CMY format.

  In the present invention, since the black generation method can be changed by changing the black generation method for each type of drawing object even for the data after the logical operation, beautiful image data can be printed without a sense of incongruity. It becomes possible.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  This embodiment is a color image processing apparatus that processes color image data including each color component of cyan (C), magenta (M), and yellow (Y). In particular, this color image processing apparatus generates optimum black (K) data for each drawing object based on CMY three-color plane data.

  First, the color image processing apparatus shown as the first embodiment will be described. As will be described in detail later, this color image processing apparatus has conventionally generated black for each page based on multi-value three-color print data composed of CMY three-color plane data after a so-called raster operation (ROP). However, black generation is performed for each drawing object before the raster operation.

Specifically, as shown in FIG. 1, the color image processing apparatus creates intermediate format data D ₂ for printing from print data D ₁ described in a predetermined page description language (PDL). The edit processing unit 11, the black generation unit 12 that generates black based on the intermediate format data D ₂ created by the edit processing unit 11, and the multi-value four-color print data D _{3 that} is output from the black generation unit 12 And a multi-value logic operation unit 13 for creating image data D ₄ for multi-value four-color printing.

Editing processing unit 11, for example, the color printer image processing apparatus is applied to decrypt the print data D ₁ described in a predetermined page description language can be analyzed, the display list including information of the drawing object, i.e., to create an intermediate format data D ₂ for printing. The intermediate format data _{D 2} are all cyan (C), magenta (M), are unified in the data for yellow (Y). Editing unit 11, the print data D ₁ expressed in the so-called RGB format, cyan (C) by performing color matching, magenta (M), after converting to the three-color data of yellow (Y) to create an intermediate format data _{D 2.} Editing unit 11 supplies the intermediate format data D ₂ created the black generation unit 12.

Black generation unit 12 performs black generation based on the intermediate format data D ₂ created by the editing unit 11, and generates the plain data. At this time, the black generation unit 12 performs optimal black generation depending on the function of the print engine for each type of drawing object. Note that the type of drawing object is a group of objects for which the black generation method is to be changed, such as an image, a graphic, a texture, and a text. For example, the black generation unit 12 converts all mixed color blacks to single color black in the case of text, and converts 20% of mixed color blacks to single color black in the case of graphics. Black generation is performed for each type. The black generation unit 12 generates multi-value four-color print data D ₃ composed of CMY three-color plane data created by performing such black generation and mixed-color black plane data based on the CMY three-color plane data. It supplies to the calculating part 13.

Multivalued logic operation unit 13, to the multi-value 4-color print data D ₃ created by the black generation unit 12, for example, overlapping or the like by the source and destination logical product or logical sum, a predetermined logical operation expression using performs superimposition processing, multi-level 4-color printing image data D ₄ creates and an output for performing multi-value four-color printing.

In such a color image processing apparatus, the multi-value logic operation unit 13 performs a predetermined multi-value logic operation on the basis of CMY _three- color plane data among the multi-value four-color print data D ₃ created by the black generation unit 12. It was carried out, based on the K data before and after the multi-value logical operation, to create a final multi-value four-color printing image data D ₄ to be output.

Specifically, as shown in FIG. 2, the multi-value logic operation unit 13 includes a mixed-color black extraction unit 21 that extracts the extracted mixed-color black data D ₅ from the multi-value four-color print data D ₃ , and multi-value four-color printing. from the data D ₃ and black data reflecting unit 22 to create a multi-level three-color print data D _6, the image data D for multilevel three-color printing from the multi-level three-color print data D ₆ created by the black data reflecting unit 22 ₇ , multi-color multi-value logic operation unit 23 for creating ₇ , multi-value 3-color printing image data D ₇ created by this 3-color multi-value logic operation unit 23, and extracted mixed color black extracted by mixed color black extraction unit 21 A black image data creation unit 24 that creates multi-value four-color printing image data D ₄ from the data D ₅ .

The mixed-color black extraction unit 21 extracts extracted mixed-color black data D _{5 including} pixels represented by the mixed-color black before the logical operation from the multi-value four-color print data D ₃ created by the black generation unit 12. Specifically, as shown in FIG. 3, the mixed color black extraction unit 21 extracts the mixed color black data D _5P from the pattern multi-value four-color print data D _3P, and the source multi-value. A mixed color black extraction processing unit 32 for extracting the mixed color black data D _5S from the four color print data D _3S, and a mixed color black extraction processing unit 33 for extracting the mixed color black data D _5D from the multi-value four-color print data D _{3D of} the destination; Have The mixed color black extraction unit 21 compares the three mixed color black data D _5P , D _5S , and D _5D extracted by each of the three mixed color black extraction processing units 31, 32, and 33 for each pixel, determining those having the tone value as the extraction mixed color black data D ₅ having a color mixing black determination processing unit 34 to be stored in a memory or the like. Such a mixed color black extraction unit 21 supplies the extracted mixed color black data D ₅ to the black image data creation unit 24.

The black data reflecting unit 22 distributes the K data in the multi-value four-color print data D ₃ created by the black generation unit 12 to each of the CMY data, thereby obtaining the multi-value three-color print data D ₆ composed of CMY three colors. create. Specifically, as shown in FIG. 4, the black data reflection unit 22 refers to the multi-value four-color print data D _3P of the pattern, and reflects the black plane data in the other color plane data. Referring to section 41, source multi-value four-color print data D _3S , black data reflection processing section 42 for reflecting black plane data to other color plane data, and destination multi-value four-color print data D _3D And a black data reflection processing unit 43 for reflecting black plane data to plane data of other colors. Note that the reflection processing by these three black data reflection processing units 41, 42, and 43 is as follows: “Pixels existing in the monochrome black plane data are mixed by cyan (C), magenta (M), and yellow (Y). It is based on the idea that it is logically the same as the resulting black pixel. Such a black data reflecting unit 22 includes the pattern multi-value three-color print data D _6P created by the black data reflection processing unit 41 and the source multi-value three-color print data created by the black data reflection processing unit 42. D _6S and supplies the multi-level three-color print data D ₆ consisting of a multi-level three-color print data D _6D of the destination that was created in three colors multivalued logic operation unit 23 by the black data reflection processing unit 43.

The three-color multi-value logic operation unit 23 performs a superimposition process on the multi-value three-color print data D ₆ created by the black data reflection unit 22 using a predetermined logic operation expression, and multi-value three-color print to create a multi-level three-color printing image data D ₇ to perform. The multi-value three-color printing image data D ₇ created by the three-color multi-value logic operation unit 23 needs to generate black. Therefore, the three-color multi-value logic operation unit 23 supplies the created multi-value three-color printing image data D ₇ to the black image data creation unit 24.

The black image data creation unit 24 is based on the multi-value three-color printing image data D ₇ created by the three-color multi-value logic operation unit 23 and the extracted mixed color black data D ₅ extracted by the mixed color black extraction unit 21. Te, to create a multi-level four-color printing for the image data D _4. Specifically, as shown in FIG. 5, the black image data creation unit 24 performs the logical operation based on the multi-value three-color printing image data D ₇ created by the three-color multi-value logic operation unit 23. a mixed color black extraction processing unit 51 for extracting color mixing black data D _8, before the logical operations that are extracted by mixing black data D ₈ and mixed black extraction unit 21 after the logical operation, which is extracted by the mixing black extraction processing unit 51 based on the extracted mixed color black data D _5, and a black plane generating unit 52 for generating the black plane data. Here, the black plane generating unit 52 is operated so as to leave the mixing black data gradation values of mixed color black extraction unit 21 extracts color mixing black data D ₅ extracted by prior logic operation as an upper limit. Then, the black plane generating unit 52, when the mixed color black data exceeding the gradation values of the extracted mixed color black data D ₅ before logic operation is present, or is from the original black black produced by logical operation It is assumed that it was plain data, and is converted to black plain data. Such black image data generation unit 24, a mixed color black data D ₈ extracted by the extracting mixed color black data D ₅ before logic operation compared for each pixel, leaving those small tone values, logic Tone data that should remain as mixed color black data after calculation is created. Then, the black image data generation unit 24, the color mixture black data D ₈ after logical operation by subtracting the gray level data should remain as even mixed color black data after the logical operation for each pixel, finally multilevel four-color printing to create a black plane data constituting use image data D _4. Further, the black image data creation unit 24 subtracts the mixed-color black data that should remain as the mixed-color black data after the logical operation from the mixed-color black data after the logical operation when generating plain data other than black, and obtains the result for each color. It is obtained by subtracting from the gradation value. Black image data generating unit 24, thus creating a multi-value four-color printing image data D _4.

  Specifically, the multi-value logic operation unit 13 performs a raster operation based on an algorithm as shown in FIG. In the figure, a case where data of 256 gradations is handled is shown, and a numerical value described in a rectangle representing the data represents a gradation value of the data.

In other words, the multi-value logic operation unit 13 has three pieces of pixel data (multi-value four-color print data D _3P , D _3S , D) to be subjected to the logic operation of the pattern (PTN), source (SRC), and destination (DST). _3D ), the three multi-value four-color print data D _3P , D _3S , and D _3D are supplied to the mixed-color black extraction processing units 31, 32, and 33, respectively, and how much mixed-color black exists. To extract. This extraction is performed by finding the smallest tone value among the three colors of cyan (C), magenta (M), and yellow (Y). The multi-value logic operation unit 13 compares the extracted three mixed color black data (process black) D _5P , D _5S , D _5D for each pixel by the mixed color black determination processing unit 34, and only those having the maximum gradation value It left as extracting color mixing black data D ₅ is a compensation value, others discarding. The reason why the three extracted mixed color black data D _5P , D _5S , and D _5D are not handled as a single color black is to avoid the determination when, for example, an inverted portion exists in the image.

Thereafter, the multi-value logic operation unit 13 supplies the multi-value four-color print data D _3P , D _3S , D _3D before the logic operation to the black data reflection processing unit 41. Then, the multi-value logic operation unit 13 is caused by the black data reflection processing unit 41 based on the multi-value four-color print data D _3P , D _3S , D _3D .
Cyan (C) gradation value = cyan (C) gradation value + black (K) gradation value magenta (M) gradation value = magenta (M) gradation value + black (K) Tone value Yellow (Y) tone value = yellow (Y) tone value + black (K) tone value is calculated. In other words, the multi-value logic operation unit 13 performs simple addition based on the idea that the black of the single color and the mixed black of the three colors are logically the same, and converts the single black to the mixed color. Convert to mixed color black. Here, depending on the specifications of the black generation processing, as a result of simple addition, the maximum gradation value 255 that can be expressed in 256 gradations may be exceeded. Therefore, the multi-value logic operation unit 13 performs the processing after this addition processing by expanding the number of gradations of one pixel from 8 bits to 16 bits.

When the multi-value logic operation unit 13 creates the multi-value three-color print data D _6P , D _6S , and D _6D by the black data reflection processing unit 41, the multi-value three-color print data D _6P , D _6S , and D _6D are The three-color multi-value logic operation unit 23 superimposes 256-level CMY three-color plane data. Then, the multi-value logic operation unit 13 extracts the mixed-color black data D ₈ by the mixed-color black extraction processing unit 51 from the multi-value three-color printing image data D ₇ after the logic operation.

After that, the multi-value logic operation unit 13 was originally black of a single color. However, in order to make the black component mixed color black as a result of the logic operation, the black plane generation processing unit 52 performs the toner black calculation process. I do. That is, multivalued logic operation unit 13 inputs the extraction mixed color black data D ₅ and mixed color black data D ₈ black plane generating unit 52, as described above, the tone values of the extracted mixed color black data D ₅ The gradation value that should be left as mixed color black data is calculated as the upper limit as follows.
Toner black gray value = gradation value of mixed color black data D ₈ - tone values of the extracted mixed color black data D ₅

However, multi-value logic operation unit 13, if the calculation result is a negative value by this calculation, namely, when the gradation value of the extracted mixed color black data D ₅ is greater than the tone value of the mixed color black data D ₈ Except that the toner black gradation value is 0.

Then, the multi-value logic operation unit 13 performs black return processing by the black plane generation processing unit 52 based on the calculated toner black gradation value D ₉ and the multi-value three-color printing image data D ₇ after the logic operation. It was carried out, to create a multi-value four-color printing image data D ₄ consisting finally be output CMYK4 colors. The black return process is performed by performing the following calculation.
Cyan (C) tone value = cyan (C) tone value-toner black tone value D _{9 in} multi-value three-color printing image data D ₇ after logical operation
Magenta (M) tone value = Magenta (M) tone value-toner black tone value D _{9 in} multi-value three-color printing image data D ₇ after logical operation
Yellow (Y) gradation value = Yellow (Y) gradation value-toner black gradation value D _{9 in} multi-value three-color printing image data D ₇ after logical operation

  Note that the multi-value logic operation unit 13 rounds to the maximum gradation value 255 when the maximum gradation value 255 that can be expressed in 256 gradations is exceeded as a result of this calculation.

The multi-value logic operation unit 13 creates multi-value four-color printing image data D ₄ based on such an algorithm.

  As shown in FIG. 7, the color image processing apparatus provided with such a multi-value logic operation unit 13 performs a series of image processing in a four-color multi-value raster operation. For comparison, FIG. 8 shows a series of image processing in the conventional three-color multi-value raster operation.

First, in the conventional image processing, as shown in FIG. 8, when print data D ₁ ′ such as color image data or texture data expressed in RGB format is input, this print data D ₁ ′ is necessary. After performing compression processing or the like according to the above, color matching is performed for each drawing object, and conversion from the RGB format to the CMY format is performed. The drawing object after conversion to the CMY format is managed as intermediate format data D ₂ ′ as a display list. Thereafter, in the conventional image processing, the intermediate format data D ₂ ′ is subjected to expansion processing or the like as necessary, and then, for example, 256 gradation CMY three-color plane data is overlaid for each drawing object. Processing is performed to create multi-value three-color print data D ₃ ′. In the conventional image processing, black generation is executed for the entire obtained page, and image data for multi-value four-color printing composed of four colors of CMYK is created.

In contrast, in the color image processing apparatus shown as an embodiment, as shown in FIG. 7, in a conventional manner by entering the print data D ₁ of the color image data and the texture data or the like expressed in the RGB format The print data D ₁ is subjected to compression processing or the like as necessary, color matching is performed for each drawing object to convert from RGB format to CMY format, and the CMY format converted drawing object and managed as an intermediate format data D ₂ as a display list. Thereafter, the color image processing apparatus, the intermediate format data D _2, after applying the expansion processing or the like, if necessary, performs black generation for each drawing object, the multi-level 4 consisting CMYK4 color plane data Color print data D ₃ is created, and based on this multi-value four-color print data D ₃ , for example, 256-level CMYK four-color plane data is overlaid, and multi-value four-color print image data D ₄ is obtained. create.

  In this way, in the color image processing apparatus, black is generated for each drawing object, not for each page, and thereafter, three colors are superimposed, and based on this, the value generated for each type of drawing object is generated. Can be reflected to change the method of black generation.

  As described above, in the color image processing apparatus shown as the first embodiment of the present invention, by generating black based on information obtained by color matching, an optimum condition for each type of drawing object Since the black component can be generated by this, it is possible to effectively use monochromatic black plane data. Therefore, in a color image processing apparatus, for example, in the case of an image, mixed color black is frequently used, while for graphics, text, etc., monochromatic black is actively used for each drawing object type. By changing the black generation method, it is possible to print beautiful image data without a sense of incongruity.

  Next, a color image processing apparatus shown as the second embodiment will be described.

  The color image processing apparatus shown as the second embodiment is obtained by adding a function for converting the number of gradations that can be expressed by the printing apparatus to the color image processing apparatus shown as the first embodiment. is there. Therefore, in the description of the second embodiment, the same components as those in the description of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 9, the color image processing apparatus shown as the second embodiment includes a multi-value logic operation unit in addition to the edit processing unit 11, the black generation unit 12, and the multi-value logic operation unit 13 described above. printer multi-value four-color printing image data D ₄ created by 13 comprises a gradation conversion unit 61 for converting the number of gradations that can be expressed.

The gradation converting unit 61 multi-value four-color printing image data D ₁₀ that matches the multi-value four-color printing image data D ₄ created by the multi-value logic operation unit 13 with the number of gradations that can be expressed by the printing apparatus. Convert to and output.

In such a color image processing apparatus, after logical operation by the multi-value logic operation unit 13, the printing device a multi-value four-color printing image data D ₄ can be dropped to the number of gradations that can be expressed. Therefore, in the color image processing apparatus, it is possible to design the multi-value logic operation unit 13 without regard to the number of gradations that can be expressed by the printing apparatus.

  Finally, a color image processing apparatus shown as the third embodiment will be described.

  The color image processing apparatus shown as the third embodiment improves the color image processing apparatus shown as the first embodiment and the second embodiment, and generates black and gray levels immediately after color matching. Correction. Accordingly, in the description of the third embodiment, the same reference numerals are given to the same configurations as those in the first embodiment and the second embodiment, and the detailed description thereof is omitted. To do.

  In the color image processing apparatus, each process can be realized by software, but is generally realized by hardware. The color image processing apparatus shown as the third embodiment is effective when each process is realized by hardware. Specifically, as shown in FIG. 10, the color image processing apparatus performs a series of image processing in a four-color multi-value raster operation.

That is, in the color image processing apparatus shown as the first embodiment and the second embodiment, as shown in FIG. 7 above, black generation and tone correction after decompression of the intermediate format data D ₂ When (MKK) is performed, in the color image processing apparatus shown as the third embodiment, as shown in FIG. 10, immediately after color matching by a predetermined hardware circuit that implements the editing processing unit 11. Then, black generation and gradation correction are performed by a predetermined hardware circuit that implements the black generation unit 12. Thereafter, in the color image processing apparatus, display coding is performed as multi-value four-color print data composed of CMYK four-color plane data obtained by performing black generation and gradation correction. In the color image processing apparatus, the data compressed as multi-value four-color print data is expanded, for example, 256-level CMYK four-color plane data is superimposed, and multi-value four-color print image data is converted. create.

  In this way, in a color image processing apparatus, a display circuit after color matching is implemented via a data bus by combining a hardware circuit that performs color matching with a hardware circuit that performs black generation and gradation correction. There is no need to write to the memory and to read the display list from the real memory via the data bus. Therefore, in the color image processing apparatus, the amount of data written to the real memory and the amount of data read from the real memory can be reduced, so the load on the data bus can be reduced and high-speed development processing is realized. can do.

  The present invention is not limited to the embodiment described above. For example, in the embodiment described above, the number of gradations (levels) that can be handled is not mentioned, but the present invention can be realized with all the gradation numbers including two gradations.

  In addition, the present invention can be applied to any device that performs the above-described image processing. For example, the present invention can be applied to a printer, a facsimile machine, a copying machine, and an apparatus having these functions in combination. It is preferable.

  Thus, it goes without saying that the present invention can be modified as appropriate without departing from the spirit of the present invention.

1 is a block diagram illustrating a configuration of a color image processing apparatus shown as a first embodiment of the present invention. It is a block diagram explaining the structure of the multi-value logic operation part in the color image processing apparatus. It is a block diagram explaining the structure of the mixed color black extraction part in the multi-value logic operation part. It is a block diagram explaining the structure of the black data reflection part in the multi-value logic operation part. It is a block diagram explaining the structure of the black image data preparation part in the multi-valued logic operation part. It is a figure explaining the specific example of the algorithm which performs a raster operation in the multi-value logic operation part. It is a figure explaining a series of image processing in the 4-color multi-value raster operation in the color image processing apparatus. It is a figure explaining a series of image processing in the conventional 3 color multi-value raster operation. It is a block diagram explaining the structure of the color image processing apparatus shown as the 2nd Embodiment of this invention. It is a figure explaining a series of image processing in the 4 color multi-value raster operation in the color image processing apparatus shown as the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Edit processing part 12 Black generation part 13 Multi-value logic operation part 21 Mixed color black extraction part 22 Black data reflection part 23 Three-color multi-value logic operation part 24 Black image data creation part 31, 32, 33 Mixed color black extraction process part 34 Mixed color Black determination processing unit 41, 42, 43 Black data reflection processing unit 51 Mixed color black extraction processing unit 52 Black plane generation processing unit 61 Tone conversion unit D ₁ Print data D ₂ Intermediate format data D ₃ Multi-value 4-color print data D _3D Multi-value 4-color printing data (destination)
D _3P multi-value 4-color printing data (pattern)
D _3S multi-value 4-color printing data (source)
D ₄ , D ₁₀ Multi-value 4-color printing image data D ₅ Extracted mixed color black data D _5D Mixed color black data (destination)
D _5P mixed color black data (pattern)
D _5S mixed color black data (source)
D ₆ multi-value 3-color print data D _6D multi-value 3-color print data (destination)
D _6P multi-value 3-color printing data (pattern)
D _6S multi-value three-color printing data (source)
D ₇ Multi-value 3-color printing image data D ₈ Mixed color black data (after logic operation)
D ₉ Toner Black Tone Value

Claims (9)

A color image processing apparatus for processing color image data including color components of a plurality of colors,
First black generation means for generating first black data corresponding to the type of drawing object from the input first color image data;
Logical operation means for performing logical operation based on the first color image data and generating second color image data;
And second black generation means for generating the second black data from the second color image data based on the first black data generated by the first black generation means. A color image processing apparatus. The color image processing apparatus according to claim 1, wherein the first color image data includes color components of cyan, magenta, and yellow. The first black generation means compares the black data generated from each of the pattern, source, and destination of the first color image data, and the one having the maximum gradation value is the first black data. The color image processing apparatus according to claim 1, further comprising a mixed color black determination processing unit that determines The second black generating means includes
A post-logical operation black generating means for generating black data after the logical operation based on the second color image data;
The second black data is generated based on the black data generated by the black generation means after the logical operation and the first black data before the logical operation generated by the first black generation means. And a third black generating means
2. The color image according to claim 1, wherein the third black generation unit calculates a gradation value to be left as the second black data with the gradation value of the first black data as an upper limit. Processing equipment. 5. The second black generation means, when the gradation value of the first black data is larger than the gradation value of the second black data, makes the monochrome black. Color image processing device. The second black generation means compares the black data generated after the logical operation with the first black data for each pixel, and leaves a data having a small gradation value, thereby leaving the data to be left as black data. The color image processing apparatus according to claim 4, wherein tone data is generated, and the second black data is generated by subtracting the gradation data from the black data for each pixel. The second black generation means subtracts the gradation data from the mixed color black data after the logical operation, and subtracts the result from the gradation values of the other colors to generate data of other colors. A color image processing apparatus according to claim 6. The color image processing apparatus according to claim 1, further comprising a gradation conversion unit that converts the number of gradations of the second color image data. The first color image data is data obtained by performing color matching on color image data expressed in RGB format and converting the color image data into color image data expressed in CMY format. Color image processing device.