JP5959815B2 - Image processing apparatus and method - Google Patents

Description

  The present invention relates to image processing when a transparent color material is used for image formation.

  Digital printing technology has been steadily increasing its utility value in recent years in the on-demand printing market and the small number of document printing market. In particular, full-color printing using an electrophotographic method is superior to other printing technologies in terms of productivity, printing cost, and ease of maintenance, and the market is rapidly expanding.

  Under such circumstances, not only full-color printing by electrophotography using CMYK colored toner but also printing using special toner is attracting attention. For example, there is a printing method using CMYK colored toner and transparent toner. The transparent toner is a toner using a substantially colorless and transparent color material having no specific hue. Gloss uniformity can be improved by using a transparent toner, and watermark characters and watermark figures can be added to printed matter by using gloss difference.

  In the electrophotographic system, generally, when the total amount of toner increases, transfer failure and fixing failure tend to occur, and the total amount of toner is often limited in units of pixels or small areas. When using transparent toner, it is necessary to consider the total amount of toner, and various techniques have been proposed for limiting the total amount of colored toner and transparent toner.

  For example, Patent Document 1 discloses a technique for reducing the total amount of colored toner in an area where transparent toner is used. Further, for example, Patent Document 2 discloses a technique for suppressing the color difference between the use area and the non-use area of the transparent toner by changing the color conversion within the range of the total toner amount limit.

  In addition, there is a printing method in which unevenness is provided on the surface of an output product by reprinting the transparent toner a plurality of times. That is, the image forming process in which the transparent toner is superimposed on the surface of the printed material after fixing the colored color material is repeated, and the transparent color material is thickly expressed to express the unevenness, thereby increasing the added value of the printed material.

  When the transparent toner is overprinted multiple times, an area where the amount of transparent color material used is relatively large (hereinafter referred to as a “used area”) and an area where the amount of transparent color material used is relatively small or unused (hereinafter referred to as “unused area”). , A non-useful area) occurs. The color reproducibility in the multi-use area and the color reproducibility in the non-use area are clearly different. The color reproducibility depends on the amount of applied toner, the number of reprints, and the fixing conditions (heat quantity, pressure, process speed) ), Depending on various conditions such as the type of recording paper and basis weight. In particular, in the multi-use area, the colored material located in the lower layer of the multi-use area tends to be more crushed and spread. For this reason, the density of the heavily used region is higher than that of the non-used region, and the change in color reproducibility is visually noticeable.

  The techniques disclosed in Patent Documents 1 and 2 do not take into account the various conditions and phenomena described above in the reprinting of transparent toner, and thus suppress the difference in color reproducibility between the heavily used area and the unusable area of the transparent color material. I can't.

JP 2007-155963 A JP 2010-194979

The present invention, when using a transparent color material to the image forming, an object of intensive region and suppression of the difference color reproducibility in non-intensive areas such as transparent coloring material.

  The present invention has the following configuration as one means for achieving the above object.

The image processing according to the present invention is formed using the first color material when generating image data for forming an image on a recording medium using the first color material and the second color material. Input image data of an image to be input, input image data of a pattern formed using the second color material, and at least the second color material when forming an image represented by the input image data The condition for inputting the pattern forming condition indicating the number of times of image formation for forming the pattern using the image data, and using the conversion table corresponding to the forming condition, the image data of the image is converted to the first color material. The image data is converted into image data corresponding to the usage amount, and the image data of the pattern is converted into image data corresponding to the usage amount of the second color material.

According to the present invention, it is possible to suppress a difference in color reproducibility between a frequently used area and a non-usable area such as a transparent color material when a transparent color material or the like is used for image formation.

1 is a block diagram illustrating a configuration example of an image processing apparatus according to an embodiment. The figure explaining the external appearance of an image processing apparatus. The block diagram explaining the functional structural example of the image process of a controller part. 6 is a flowchart for explaining print processing. The figure explaining the UI example which designates a transparent pattern. The figure which shows an example which added the transparent pattern to the image. The figure explaining the UI example which sets the formation conditions of a transparent image. 6 is a flowchart for explaining an example of a procedure for creating a color separation LUT.

  Hereinafter, image processing according to an embodiment of the present invention will be described in detail with reference to the drawings.

[Device configuration]
A configuration example of the image processing apparatus 1000 according to the embodiment will be described with reference to the block diagram of FIG. Hereinafter, a digital multifunction peripheral (MFP) having a scanner function, a copy function, a print function, a facsimile function, and the like will be described as an example of the image processing apparatus 1000.

  In the image processing apparatus 1000, the scanner unit 1001 reads a document image. The controller unit 1002 performs various types of image processing on the image data output from the scanner unit 1001 and stores the image data in the memory 1005. The printer unit 1003 forms a visible image on a recording medium by electrophotography according to various printing conditions set via the operation unit 1004 and image data read from the memory 1005.

  The image processing apparatus 1000 is connected to a server 1007 that manages image data and a personal computer (PC) 1008 that instructs the image processing apparatus 1000 to execute printing via a network 1006 such as a LAN. The That is, the controller unit 1002 of the image processing apparatus 1000 scans a document image or executes image formation based on image data output from the PC 1008 or image data stored in the server 1007 in accordance with an instruction from the PC 1008.

[Overview of the device]
An overview of the image processing apparatus 1000 will be described with reference to FIG.

  In the scanner unit 1001, the light of the lamp 205 is irradiated on the original 204 placed between the specular pressure plate 200 and the original table glass 203. Reflected light from the original 204 is guided to mirrors 206, 207 and 208, and an image is formed on a three-line image sensor (hereinafter, CCD) 210 by a lens 209. Three image signals of red (R), green (G), and blue (B) output from the CCD 210 are sent to the controller unit 1002. The lamp 205 and the mirror 206 are moved at a speed V, and the mirrors 207 and 208 are moved at a speed V / 2 in a direction perpendicular to the electrical scanning (main scanning) direction of the CCD 210, thereby Are scanned (sub-scanned).

  The image of the original 204 is read at a resolution of, for example, 600 dpi for both main scanning and sub scanning. A controller unit 1002 inputs an image signal from the scanner unit 1001 and performs image processing for each page of a document. In other words, the input image signal is electrically processed and separated into magenta (M), cyan (C), yellow (Y), and black (K) process color components, and the CMYK image signal is stored in the memory 1005. Stored in a predetermined area. Then, the CMYK image signal stored in the memory 1005 is sent to the printer unit 1003 in frame order.

  Although details will be described later, the controller unit 1002 has a function of generating an image for a transparent color material (CL), generates a plurality of image signals CL0, CL1, and CL2 in units of pixels and outputs them to the printer unit 1003. . The image signal CL0 represents a transparent image T0 that is formed simultaneously with the image formation with the CMYK color material. Further, the image signal CL1 represents the transparent image T1 to be additionally printed after the formation of the transparent image T0, and the image signal CL2 represents the transparent image T2 to be additionally printed after the formation of the transparent image T1. In other words, the image signals CL0, CL1, and CL2 are image data corresponding to the usage amount of the transparent color material at each time of image formation using the transparent color material.

  In the printer unit 1003, the C, M, Y, K, or CL0 image signal input from the controller unit 1002 is sent to the laser driver 212. The laser driver 212 modulates and drives the semiconductor laser element 213 according to the input image signal. The laser beam output from the semiconductor laser element 213 scans the photosensitive drum 217 through the polygon mirror 214, the f-θ lens 215, and the mirror 216, and the electrostatic latent image of 600 dpi, for example, is scanned on the photosensitive drum 217 in both main scanning and sub scanning. Form an image.

  The rotary developing unit 218 includes an M developing unit 219, a C developing unit 220, a Y developing unit 221, a K developing unit 222, and a CL developing unit 223, and five developing units are alternately in contact with the photosensitive drum 217, and the photosensitive drum The electrostatic development formed on 217 is developed with toner of each color. A recording sheet supplied from a recording sheet cassette 225 or 226 is wound around the transfer drum 224, and a toner image formed on the photosensitive drum 217 is transferred to the recording sheet.

  In this manner, the five color toner images of M, C, Y, K, and CL are sequentially transferred onto the recording paper, and then the recording paper passes through the fixing device 227 to fix the color material. When the transparent image T1 is not formed, the recording paper is discharged out of the apparatus. When the transparent image T1 is formed, the recording paper is returned to the first stage of the paper path, and the transparent image T1 is transferred and fixed. Further, when forming the transparent image T2, the recording paper is returned again to the first stage of the paper path, and after the transparent image T2 is transferred and fixed, it is discharged out of the apparatus.

[Image processing]
A functional configuration example of image processing of the controller unit 1002 will be described with reference to the block diagram of FIG.

  The image data input unit 101 performs various image processing such as background processing and gamma correction on the image signal received from the scanner unit 1001, and stores the processed image data in a predetermined area of the memory 1005 in units of pages. When a print job is received from the PC 1008, image data included in the print job is stored in a predetermined area of the memory 1005 in units of pages. The input image data is representative of signals of three colors of red (R), green (G), and blue (B) and 256 gradations for each color, but is not limited thereto.

  The transparent pattern designating unit 102 is a user interface (UI) that accepts designation of a transparent image formation pattern from the user. As the transparent pattern designating unit 102, for example, a UI displayed on the touch panel of the operation unit 1004 or a UI provided by software such as a printer driver running on the PC 1008 can be used.

  In the following, an example will be described in which the transparent toner is overprinted a plurality of times to provide unevenness on the surface of the printed material (color image region or paper surface of the printed material). For example, the user designates a pattern such as a texture, a specific pattern, a character, or a graphic as the unevenness on the surface of the printed material. Alternatively, a pattern corresponding to the image data input by the image data input unit 101 can be specified.

  The transparent image generation unit 103 inputs information on the transparent pattern designated by the transparent pattern designation unit 102. Then, in accordance with the input transparent pattern information, bitmap format image data CL representing an image to be formed with transparent toner is generated, and the CL data is stored in a predetermined area of the memory 1005.

  The formation condition setting unit 104 sets various conditions related to the formation of a transparent image. Various conditions include the number of transparent image formations, fixing conditions for transparent toner (heat quantity, pressure, printing speed), and characteristics of the recording medium (type, basis weight). The set formation conditions are stored in a predetermined area of the memory 1005. As the formation condition setting unit 104, a UI of the operation unit 1004 or a UI provided by software such as a printer driver running on the PC 1008 can be used. Further, the fixing condition may be acquired from an internal setting value of the image processing apparatus 100, a recording mode, sensor information, or the like. The characteristics of the recording medium can include not only the type and basis weight but also parameters that affect the formation of a transparent image, such as paper thickness (paper thickness) and surface smoothness.

  The transparent pattern may be specified before scanning the document image or when instructing to print the image. Of course, the transparent pattern is specified, the transparent image is generated, and the formation conditions are set in advance and stored in the memory 1005. The user selects the desired transparent pattern and formation conditions, and the transparent corresponding to the selected transparent pattern. Images and selected formation conditions may be used.

  When the image forming process is started under the control of the controller unit 1002, the color conversion unit 105 inputs the forming conditions from the memory 1005, and inputs RGB data and CL data in units of pixels. Then, RGB data in the device color space of the scanner 201 or a standard RGB color space (for example, sRGB) is converted into CMYK data in the device color space of the printer unit 1003. Further, the CL data is converted into CL0, CL1, and CL2 data for forming a transparent image based on the input formation conditions.

  The gradation correction unit 106 performs gradation correction on the CMYK data and the CL0, CL1, and CL2 data output from the color conversion unit 105 so that appropriate gradation characteristics can be obtained in the printed material. The halftone processing unit 107 performs pseudo-halftone processing such as dithering and error diffusion on the CMYK data and CL0, CL1, and CL2 data output from the gradation correction unit 106, and generates CMYK data and CL0, CL1, and CL2. Reduce the number of data gradations.

  Based on the image data input from the halftone processing unit 107, the printer unit 1003 generates a printed matter in which a full-color image using a CMYK color material and a transparent image using a transparent color material are formed on a recording medium. .

[Print processing]
The printing process will be described with reference to the flowchart of FIG. The process shown in FIG. 4 is executed under the control of the controller unit 1002.

  The controller unit 1002 accepts a transparent pattern designation by the transparent pattern designation unit 102 (S401), and the transparent image generation unit 103 generates CL data of the transparent image (S402). Further, the forming condition setting unit 104 sets the forming condition of the transparent image (S403).

  Next, the controller unit 1002 inputs image data to be printed by the image data input unit 101 (S404), and starts an image forming process.

  When the image forming process is started, the color conversion unit 105 executes the above-described color conversion process in the surface order (S405), and the gradation correction unit 106 executes the above-described gradation correction process (S406). The tone processing unit 107 executes the above-described pseudo halftone processing (S407). The controller unit 1002 outputs the image data subjected to the color conversion process, the gradation correction process, and the pseudo halftone process to the printer unit 1003 in units of pixels (S408).

  Next, the controller unit 1002 determines whether or not the image forming process of each color component and each transparent component is completed (S409), and if there is a color component or a transparent component for which the image forming process has not been completed, the process is performed. Return to S405.

[Specify transparent pattern]
An example of a UI for designating a transparent pattern will be described with reference to FIG.

  The UI shown in FIG. 5 includes a graphic pattern designation unit 501, a specific character string designation unit 502, an arbitrary character string designation unit 503, a date designation unit 504, a size designation unit 505, an inclination designation unit 506, and a thickness designation unit 507. . Depending on whether or not a check box associated with each designated portion is checked, the validity of the designated portion can be set (not used for designating a transparent pattern).

  The user selects a graphic pattern registered in advance from the drop-down menu of the graphic pattern designating unit 501. Also, a specific character string (for example, “Hello”, “Happy New Year”, etc.) registered in advance is selected from the drop-down menu of the specific character string designating unit 502. Further, the user registers a new graphic pattern or specific character string by pressing a “registration” button in the graphic pattern specifying unit 501 or the specific character string specifying unit 502.

  The user presses an “input” button of the arbitrary character string designating unit 503 to display a software keyboard on the UI, and inputs an arbitrary character string using the software keyboard. The input character string is displayed in a text box of the arbitrary character string specifying unit 503.

  In the text box of the date designation unit 504, the date of the internal clock of the image processing apparatus 1000 is displayed. The user can also specify an arbitrary date by operating the “input” button of the date specifying unit 504.

  In the example shown in FIG. 5, the graphic pattern designation unit 501 and the arbitrary character string designation unit 503 are set to be valid. Accordingly, a graphic corresponding to the selection in the graphic pattern designation unit 501 and a character string corresponding to the input in the arbitrary character string designation unit 503 are displayed in the preview unit 513.

  The size designation unit 505, the inclination designation unit 506, and the thickness designation unit 507 are designation units for designating the characteristics of the parts constituting the transparent pattern. That is, the user selects the entire image representing the transparent pattern displayed on the preview unit 513 or each image corresponding to the component of the transparent pattern by a pointing device or a touch panel operation. Then, the size, inclination, and thickness of the selected image are designated by a drop-down menu of each designation unit.

  In addition, it is possible to select a transparent pattern component displayed in the preview unit 513 by a pointing device or a touch panel operation, and to change the size or inclination of moving the position.

  When the user presses an “image display” button 514, a document image read by the scanner unit 1001 and an image represented by image data to be printed are displayed on the preview unit 513. The user can also specify a transparent pattern by drawing a pattern directly on the preview unit 513 by a pointing device or a touch panel operation. When the user presses an “OK” button 515, the designation of the transparent pattern is completed.

  FIG. 6 shows an example in which a transparent pattern is added to the image. The original image 601 includes a character string 602, a figure 603, and a figure 604. An image 605 is an image in which the original image 601 is read by the scanner unit 1001, the read image is printed (copied) by the printer unit 1003, and a transparent pattern is added.

  A character string 606 in the image 605 is a convex character string in which the image of the character string 602 is covered with a transparent color material. The figure 607 has concave portions 607d formed at predetermined intervals after the image of the figure 603 is covered with a transparent color material. The figure 608 includes a convex portion of a transparent color material that borders the edge portion of the image of the figure 604.

[Generate transparent image]
The transparent image generation unit 103 generates a bitmap-format transparent image according to information indicating the designated transparent pattern. When the transparent pattern is a binary value indicating the presence / absence of a pattern, the CL data is 1 bit for each pixel. For example, “0” is assigned to a pixel that does not form a transparent image, and “1” is assigned to a pixel that forms a transparent image. Further, the transparent pattern can be multivalued, and thickness information can be given to the transparent pattern. In this case, CL data is set to 2 bits for each pixel, for example, '00' for pixels that do not form a transparent image, '01' for pixels that form a thin transparent image, and pixels that form a transparent image with an intermediate thickness. '10', '11' is assigned to pixels that form a thick transparent image. For example, the thin transparent image corresponds to the recess 607d shown in FIG.

  The transparent image generating unit 103 generates a transparent image having a size corresponding to each size of the recording medium that can be used by the printer unit 1003. Alternatively, a transparent image having a certain size (for example, for A4 size) may be generated, and the transparent image may be enlarged or reduced according to the size of the recording medium used for printing.

[Transparent image formation condition settings]
A UI example for setting the transparent image forming conditions will be described with reference to FIG.

  7 includes a transparent image formation number setting unit 701, a fixing condition (heat amount) setting unit 702, a fixing condition (pressure) setting unit 703, a fixing condition (process speed) setting unit 704, and a paper type setting unit 705. A paper basis weight setting unit 706 is provided.

  The user can set the number of image formations using the transparent color material by the formation number setting unit 701. Transparent image formation using CL0 data once, transparent image formation using CL0 and CL1 data twice (reprinting once), and transparent image formation using CL0, CL1 and CL2 data three times (reprinting) 2 times). If zero is set, only image formation with the CMYK color material is executed, and a transparent image is not formed.

  The user can set the amount of heat in fixing by using a fixing condition (heat amount) setting unit 702. Further, a fixing condition (pressure) setting unit 703 can set a pressure in fixing. The setting is selected from three levels, for example, strong, normal, and weak.

  The user can further set a process speed (recording medium conveyance speed) by a fixing condition (process speed) setting unit 704. The setting is selected from three stages, for example, fast, normal, and slow.

The user can set the type of the recording medium using the paper type setting unit 705. As the type of recording medium, for example, plain paper, matte paper, gloss paper, special paper, or the like can be selected. The paper basis weight setting unit 706 can set the basis weight of the recording medium. Weighing, for example, ^{64-105g / m 2, 105-157g / m} 2, can be selected such as ^{150-209g / m 2, 209g / m} 2 greater.

  Note that the forming conditions shown in FIG. 7 are merely examples. In addition to this, if the conditions are related to the formation of a transparent image, such as the thickness of the paper and the environmental temperature and humidity during image formation, they are added to the forming conditions. be able to. Further, it is not necessary to have all the formation conditions shown in FIG. 7, and only some of the conditions may be set.

  As the parameters based on the formation conditions and the number thereof are increased, the formation conditions of the transparent image can be set in detail, and the effects of the present invention can be further enhanced. However, as the parameters and the number thereof increase, the color conversion tables prepared in the color conversion unit 105 increase. In other words, a setting condition that can be set may be provided by balancing the effect and the load necessary for preparing the color conversion table.

[Color converter]
In the following, for the sake of simplicity, it is assumed that the formation conditions set by the formation condition setting unit 104 are two types of the number N of transparent image formations and the fixing condition (heat amount) Q.

The color conversion unit 105 converts the RGBCL data into CMYKCL0CL1CL2 data using the color separation look-up table (LUT) and interpolation calculation stored in the memory 1005 according to the following equation.
D_C = LUT _C (R, G, B, CL, N, Q)… (1)
D_M = LUT _M (R, G, B, CL, N, Q)… (2)
D_Y = LUT _Y (R, G, B, CL, N, Q)… (3)
D_K = LUT _K (R, G, B, CL, N, Q)… (4)
D_CL0 = LUT _CL0 (R, G, B, CL, N, Q)… (5)
D_CL1 = LUT _CL1 (R, G, B, CL, N, Q)… (6)
D_CL2 = LUT _CL2 (R, G, B, CL, N, Q)… (7)

  The functions defined on the right side of the equations (1) to (7) correspond to the contents of the color separation LUT and conversion LUT. In other words, the color separation LUT for colored color materials and the conversion LUT for transparent color materials are based on four input values of RGBCL, the number N of transparent image formations, and the fixing condition (heat amount) Q. This is a 6-input 1-output configuration that obtains any of the 3 plane output values. The reason why the RGB value is input to the conversion LUT for transparent color material is to prevent the total use amount of the color material from exceeding the limit value. The conversion LUT for transparent color material is created in advance and stored in the memory 1005.

  When N = 0, the color conversion unit 105 is a pre-designed color separation LUT (hereinafter referred to as a reference LUT) having a three-input one-output configuration that is stored in the memory 1005 and is used when a transparent image is not formed. ) And the conversion processing corresponding to equations (5)-(7) is not performed. Similarly, when N = 1, the conversion process corresponding to Expressions (6) and (7) is not performed, and when N = 2, the conversion process corresponding to Expression (7) is not performed.

In the above, an example in which color conversion processing is performed using seven six-input one-output color separation LUTs has been described. However, a four-input one-output color separation LUT and conversion LUT may be used for each combination of the number N of transparent image formations and the fixing condition (heat quantity) Q as shown in the following equation.
D_C = LUT _NQ C (R, G, B, CL)… (8)
D_M = LUT _NQ M (R, G, B, CL)… (9)
D_Y = LUT _NQ Y (R, G, B, CL)… (10)
D_K = LUT _NQ K (R, G, B, CL)… (11)
D_CL0 = LUT _NQ CL0 (R, G, B, CL)… (12)
D_CL1 = LUT _NQ CL1 (R, G, B, CL)… (13)
D_CL2 = LUT _NQ CL2 (R, G, B, CL)… (14)

LUT _NQ is a color separation table corresponding to the combination of the number of formations N and the fixing condition (heat amount) Q. The reason why the RGB value is input to the conversion LUT _NQ for transparent color material is to prevent the total use amount of the color material from exceeding the limit value. The conversion LUT _NQ for transparent color material is created in advance and stored in the memory 1005.

  Further, when N = 0, the reference LUT is used, and the conversion processing corresponding to the equations (12) to (14) is not necessary. Similarly, when N = 1, the conversion processing corresponding to equations (13) and (14) is unnecessary, and when N = 2, the conversion processing corresponding to equation (14) is unnecessary.

[Procedure for creating a color separation LUT]
A procedure for creating a color separation LUT will be described with reference to the flowchart of FIG. This creation procedure is a process executed by the controller unit 1002, and an example of creating a color separation LUT in the form of equations (8) to (11) will be described. Further, the transparent image forming conditions are set to general values (normal) except for the number N of forming times and the fixing condition (heat amount) Q.

  The controller unit 1002 sets the fixing condition (heat amount) Q of the fixing device 227 to normal (S801), and sets the reference LUT to the color conversion unit 105 (S802).

  Next, the controller unit 1002 inputs the color chart data stored in the memory 1005 to the color conversion unit 105 (S803), and starts the image forming process. The printer unit 1003 prints a color chart including a plurality of color charts having different colors corresponding to the color chart data (S804). The color chart data includes, for example, data for 729 colors corresponding to nine values for each of RGB.

  Next, the controller unit 1002 acquires (measures) RGB data (device RGB values) of each color chart of the color chart by the scanner unit 1001. Then, the colorimetric values of each color chart of the color chart are calculated, and the colorimetric values are stored as reference colorimetric values in a predetermined area of the memory 1005 (S805). The calorimetric value calculation may be performed by, for example, converting a device RGB value into an sRGB value in the sRGB space and converting the sRGB value into an Lab value (colorimetric value) in the CIELab space.

  Next, the controller unit 1002 sets conditions for forming a transparent image (S806). That is, the fixing condition (amount of heat) Q is increased and is set to either normal or weak, and the number of formations N is set to any one of 1-3. Then, the color chart data stored in the memory 1005 and the CL data (= “11”) for overlaying the transparent color material on the color chart are input to the color conversion unit 105 (S807), and the image forming process is started. The printer unit 1003 prints a color chart corresponding to the color chart data and including a plurality of color charts having different colors on which the transparent color material is superimposed once, twice or three times (S808).

  Next, the controller unit 1002 acquires (measures) the RGB data of each color chart of the color chart by the scanner unit 1001, calculates the colorimetric value of each color chart of the color chart, and stores the colorimetric value in a predetermined memory 1005 Store in the area (S809). Then, it is determined whether or not the printing and measurement of the color chart corresponding to the combination of the transparent image forming conditions has been completed (S810), and if not completed, the process returns to step S806.

When printing and measurement of the color chart are completed, the controller unit 1002 corrects the output value of the reference LUT so that the reference colorimetric value of the color chart and the color measurement value of the color chart on which the transparent color material is superimposed match. A color separation LUT _NQ X is created (S811). A known method may be used to create the color separation LUT, and “X” in the LUT _NQ X is any one of C, M, Y, and K. Then, the created color separation LUT _NQ X is stored in a predetermined area of the memory 1005 (S812).

  In this way, the controller unit 1002 creates a color separation table corresponding to the transparent image forming conditions, and executes the image forming process using the color separation table. Therefore, when using a transparent color material for image formation, it is possible to suppress the difference in color reproducibility between the frequently used area and the non-used area of the transparent color material by using a color separation table according to the transparent image forming conditions. it can.

[Modification]
According to the above embodiment, when copying a document image, a transparent image can be superimposed on the copy image. Of course, when printing an electronic document included in a print job received from the PC 1008, a transparent image can be superimposed on the document image. At that time, the image data input unit 101 executes so-called RIP (raster image processing) for rendering image data (PDL data) described in a page description language or the like into a raster image.

  The transparent pattern and transparent image forming conditions may be specified and set via a UI provided by a printer driver operating on the PC 1008. In this case, the UI shown in FIGS. 5 and 7 is displayed as a setting screen provided by the printer driver.

  In the above, the image formation using the transparent color material that is the second color material in addition to the CMYK color material that is the first color material has been described. However, the present invention can also be applied to image formation using a special color material (for example, a special color material) as the second color material. For example, even in printing that uses a fluorescent color or an orange color material as a special color material, printing is performed with a relatively large usage amount of the special color material, and the use amount of the special color material is relatively A difference in color reproducibility in a small or unused non-use area can be suppressed. As a special color material, among the process color materials of cyan, magenta, yellow, and black, the saturation is higher than the color obtained by mixing two or more colors (for example, red, green, blue). A color material having a high color can be used.

[Other Examples]
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. It is a process to be executed.

Claims (10)

An image processing apparatus for generating image data for forming an image on a recording medium using a first color material and a second color material,
An image input means for inputting image data of an image formed using the first color material;
A pattern input means for inputting image data of a pattern formed using the second color material;
The condition for inputting the pattern formation condition indicating the number of times of image formation for forming the pattern using at least the second color material when forming the image represented by the image data input by the image input means. Input means;
Using the conversion table corresponding to the formation condition, the image data of the image is converted into image data corresponding to the usage amount of the first color material, and the image data of the pattern is converted to the second color material. An image processing apparatus comprising: conversion means for converting into image data corresponding to a usage amount.   2. The image processing apparatus according to claim 1, wherein the first color material is a colored color material, and the second color material is a substantially colorless and transparent transparent color material.   The first color material is a process color color material, and the second color material has a higher saturation than a color obtained by mixing a special color material or two or more color materials of the process color. 2. The image processing device according to claim 1, wherein the image processing device is a color material.   The conversion means color-separates the image data of the image based on the image data of the image and the image data of the pattern using a conversion table corresponding to the formation conditions and the image data of the image. 4. The image processing device according to any one of claims 1 to 3.   5. The image according to claim 1, wherein the formation condition further includes at least one of a fixing condition of the second color material and a characteristic of the recording medium. Processing equipment.   The converting means converts the image data of the image based on the image data of the image and the image data of the pattern using the conversion table corresponding to the image data of the formation condition and the pattern, and the second color material. 6. The method according to claim 1, wherein the image data is converted into image data corresponding to a use amount of the second color material in each image forming time corresponding to the number of image forming times to be used. Image processing device.   2. The image processing apparatus according to claim 1, further comprising an output unit that outputs image data output from the conversion unit to an image forming apparatus that performs an image forming process using the first color material and the second color material. The image processing device according to claim 6.   8. The image processing apparatus according to claim 1, wherein the pattern represents unevenness on a surface of a printed material. An image processing method of an image processing apparatus for generating image data for forming an image on a recording medium using a first color material and a second color material,
An image input means inputs image data of an image formed using the first color material,
The pattern input means inputs pattern image data formed using the second color material,
When the condition input means forms an image represented by the input image data , it inputs the pattern formation condition indicating the number of times of image formation for forming the pattern using at least the second color material ,
A conversion unit converts the image data of the image into image data corresponding to the amount of the first color material used using a conversion table corresponding to the formation condition, and converts the image data of the pattern into the second image data. An image processing method comprising: converting the image data into image data corresponding to the amount of color material used.   A program for causing a computer to function as each unit of the image processing apparatus according to any one of claims 1 to 8.