JP2011150026A - Image processor, image processing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an image processor that maintains a certain glossiness and suppresses change of desired color information even if the amount of toner is regulated by a total regulation value; an image processing method; and a program. <P>SOLUTION: A CL adhering amount according to the glossiness to an input density of an image reproduced by color toner is determined. When the total of the determined CL adhering amount and the amount of color toner for reproducing the image exceeds the preset total regulation value, gradation processing is applied to the image, and the determined CL adhering amount and the amount of color toner for reproducing the image are reduced. When the CL adhering amount according to the glossiness to the input density of the image after the amount of color toner is reduced is smaller than the CL adhering amount after the amount is reduced, the amount of color toner for reproducing the image after the amount of color toner is reduced is decreased. When the CL adhering amount according to the glossiness to the density of the image after the amount of color toner is reduced is larger than the CL adhering amount after the amount is reduced, the amount of color toner for reproducing the image after the amount of color toner is reduced is increased. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image processing device, an image processing method, and a program.

  Conventionally, in order to give added value to colored toners such as CMYK, image forming apparatuses that use clear toner for the purpose of increasing glossiness, as well as uniform glossiness and graininess as well as increase in glossiness There are image processing devices that improve.

  For example, according to Patent Document 1, as gloss characteristics, generally, the glossiness of white paper or a solid portion is high (particularly, the glossiness of a solid portion is the highest), and the glossiness of intermediate colors tends to be low. For this reason, a process has been proposed in which the amount of clear toner is controlled so that the glossiness of the solid portion is targeted, and the glossiness is uniform over the entire surface.

  By the way, when clear toner is used to add value to colored toner, clear toner is further attached to color-mixed parts such as secondary and tertiary colors with emphasis on color reproducibility and gloss. In this case, the total amount of toner in the color mixture portion may exceed the total amount regulation value on the image forming apparatus side. In this case, there is a concern that an abnormal image due to toner fixing abnormality is output before adding value to the colored toner.

  When an image with higher glossiness is desired, there is a case where clear toner needs to be attached. In this case, due to process restrictions (for example, the total amount regulation value on the image forming apparatus side), the clear toner is required. As a result, an image having a desired glossiness may not be obtained.

  The present invention has been made in view of the above, and maintains a certain glossiness and changes in desired color information (lightness and saturation) even when the amount of toner is regulated by the total amount regulation value. It is an object of the present invention to provide an image processing apparatus, an image processing method, and a program that can suppress the deviation).

  In order to solve the above-described problems and achieve the object, the present invention provides a determining means for determining the amount of clear toner according to the glossiness with respect to the density of an image reproduced with colored toner, and the amount of the determined clear toner. When the total amount of the color toner that reproduces the image exceeds the preset total amount regulation value, the image is subjected to gradation processing, and the determined clear toner amount and the color toner that reproduces the image A reduction means for reducing the amount of the color toner, and when the amount of the clear toner corresponding to the glossiness with respect to the density of the image after the reduction of the amount of the colored toner is smaller than the amount of the clear toner after the reduction, The amount of the color toner that reproduces the image is reduced, and the amount of the color toner is larger than the amount of the clear toner after the reduction according to the glossiness with respect to the density of the image after the reduction. When, characterized by comprising a correction means for increasing the amount of color toner to reproduce the image after reduction of the amount of the color toner.

  The present invention is also an image processing method executed by an image processing apparatus, wherein the determination means determines the amount of clear toner in accordance with the glossiness with respect to the density of an image reproduced with colored toner. And when the total amount of the determined amount of clear toner and the amount of colored toner that reproduces the image exceeds a preset total amount regulation value, gradation processing is performed on the image. A reduction step of reducing the amount of the clear toner determined and the amount of the colored toner that reproduces the image; and the amount of the clear toner corresponding to the glossiness with respect to the density of the image after the reduction means reduces the amount of the colored toner Is less than the amount of the clear toner after the reduction, the amount of the color toner that reproduces the image after the reduction in the amount of the color toner is reduced, and the amount of the color toner is reduced with respect to the density of the image after the reduction. And a correction step of increasing the amount of the colored toner that reproduces the image after the reduction of the amount of the colored toner when the amount of the clear toner corresponding to the degree is larger than the amount of the clear toner after the reduction. And

  According to the present invention, the amount of the clear toner is determined according to the glossiness with respect to the density of the image reproduced with the colored toner, and the total amount of the determined amount of the clear toner and the amount of the colored toner that reproduces the image is preset. If the total amount exceeds the regulation value, the gradation processing is performed on the image, the amount of clear toner determined and the amount of colored toner that reproduces the image are reduced, and the glossiness with respect to the density of the image after the amount of colored toner is reduced If the amount of clear toner is less than the amount of clear toner after reduction, the amount of color toner that reproduces the image after reduction of the amount of color toner is reduced, and the density of the image after reduction of the amount of color toner If the amount of clear toner corresponding to the glossiness is greater than the amount of clear toner after reduction, the amount of color toner is increased to increase the amount of color toner that reproduces the image after reduction. Since the amount of clear toner can be prevented from being reduced more than necessary, even when the amount of toner is regulated by the total amount regulation process, a constant glossiness is maintained and desired color information changes (lightness) And a shift in saturation) can be suppressed.

FIG. 1 is a block diagram showing a configuration of a multifunction machine according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a specific configuration of the image data processing apparatus. FIG. 3 is a block diagram showing a more specific configuration of the toner control processing unit. FIG. 4 is a diagram showing glossiness characteristics in which input density and glossiness are associated with each other. FIG. 5 is a diagram illustrating a CL adhesion amount table. FIG. 6 is a diagram illustrating a change example of the chromaticity of the CMYKCL image due to the influence of the total amount restriction process. FIG. 7 is a diagram for classifying which hue region a2 * and b2 * are in when (a *, b *) = (a1 *, b1 *) is the center. FIG. 8 is a diagram illustrating a reduction balance of the amount of CMY color material in each hue region. FIG. 9 is a block diagram showing a specific configuration of the image data processing apparatus. FIG. 10 is a schematic diagram showing the configuration of the reading device. FIG. 11 is a schematic diagram illustrating the configuration of the glossiness detection unit. FIG. 12 is a diagram showing a gradation pattern of CMYK color materials. FIG. 13 is a diagram illustrating a first gradation pattern and a second gradation pattern.

  Exemplary embodiments of an image processing apparatus, an image processing method, and a program according to the present invention are explained in detail below with reference to the accompanying drawings. In the present embodiment, an example in which the image processing apparatus of the present invention is applied to a multi-function peripheral (MFP) having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function is given. However, the present invention can be applied to any image processing apparatus such as a copying machine, a printer, a scanner apparatus, and a facsimile apparatus.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a multifunction machine according to the first embodiment of the present invention. A multifunction peripheral 100 according to the present embodiment includes a reading device 101, an image data processing device 102, a bus control device 103, an HDD 104, a CPU 105, a memory 106, a plotter I / F device 107, a plotter device 108, an operation display device 109, a line I / F device 110, external I / F device 111, S.I. B. 112, ROM 113, and the like.

  The reading apparatus 101 generates RGB 8-bit digital image data from the density information of the original obtained by scanning the original, and outputs the digital image data to the image data processing apparatus 102.

  The image data processing device 102 performs image processing on the RGB 8-bit digital image data output from the reading device 101 and outputs the digital image data to the bus control device 103.

  The bus control device 103 exchanges various data such as necessary digital image data and control commands in the multifunction peripheral 100.

  An HDD (Hard Disk Drive) 104 is a storage device for accumulating digital image data and accompanying information of the digital image data.

  The CPU 105 is a microprocessor that controls the entire control of the multifunction peripheral 100.

  Memory 106 is a volatile memory used for temporarily storing programs and intermediate processing data when CPU 105 controls MFP 100.

  The plotter I / F device 107 is a clear toner corresponding to the CMYK digital image data (referred to as CMYK image) reproduced by the CMYK color material (colored toner) sent from the CPU 105 or the glossiness with respect to the density of the CMYK image. CMYK digital image data (referred to as CMYKCL image) to which a clear toner signal indicating the amount of toner is added is received and output to a dedicated I / F of the plotter device 108.

  When the plotter device 108 receives the CMYK digital image data, the plotter device 108 outputs an image on the transfer paper by an electrophotographic process using a laser beam.

  S. B. Reference numeral 112 denotes a general-purpose circuit that is a bridge function of a bus called South Bridge.

  A ROM (Read Only Memory) 113 is a memory that stores a program when the CPU 105 controls the multifunction peripheral 100.

  The operation display device 109 is a part that performs a user interface with the multifunction peripheral 100, and includes a liquid crystal display (LCD) and a key switch, and displays various states and operation methods of the device on the liquid crystal display device. The key switch input from the user is detected.

  Note that the multifunction device 100 exchanges image data with a FAX (Facsimile) 114 outside the multifunction device 100 via the telephone line and the line I / F device 110. The multifunction device 100 also performs various controls and digital image data input / output with a PC (Personal Computer) 115 outside the multifunction device 100 via the external I / F device 111.

  FIG. 2 is a block diagram showing a specific configuration of the image data processing apparatus. The image data processing apparatus 102 includes a scanner γ conversion unit 201, a filter processing unit 202, a toner control processing unit 300, a scaling compression unit 205, a compression processing unit 206, a gradation processing unit 207, and the like.

  The scanner γ conversion unit 201 performs γ conversion such that the density is linear with respect to 8-bit digital image data of RGB each having a linear reflectance (hereinafter referred to as RGB image).

  The filter processing unit 202 performs smoothing and edge enhancement processing on the input RGB image.

  The toner control processing unit 300 includes a color correction unit 203 and a printer γ processing unit 204. The color correction unit 203 performs a process of converting the input RGB image into CMYK digital image data (referred to as a CMYK image). The printer γ processing unit 204 corrects an output image such as addition of a clear toner signal, conversion of gradation, total amount regulation, toner control, and the like.

  A scaling compression unit 205 performs reduction and enlargement processing of the CMYK image.

  The compression processing unit 206 performs compression / decompression processing of CMYK images as necessary. The compression / decompression process may be irreversible such as JPEG, or may be a reversible compression method that prevents image degradation such as PNG in the case of decompression.

  The gradation processing unit 207 creates a dot pattern of the CMYK image according to the image forming conditions, and virtually secures the gradation of the CMYK image.

  FIG. 3 is a block diagram showing a more specific configuration of the toner control processing unit. The toner control processing unit 300 includes a 3DLUT unit 301, a UCR / UCA processing unit 302, a printer γ processing unit 303, a clear toner adding unit 304, a total amount regulating unit 305, and an adaptive CL γ processing unit 306. The 3DLUT unit 301 is included in the color correction unit 203 shown in FIG. 2. The UCR / UCA processing unit 302, the printer γ processing unit 303, the clear toner adding unit 304, the total amount regulating unit 305, and the adaptive CLγ processing unit 306 are included in the 3DLUT unit 301. 2 is included in the printer γ processing unit 204 shown in FIG.

  The 3DLUT unit 301 performs gamut mapping in accordance with a color reproduction range reproducible with a CMYK color material, and converts an RGB image into a CMY image (hereinafter referred to as a CMY image). Note that the gamut mapping uses known methods such as saturation preservation, lightness preservation, and minimum color difference.

  The UCR / UCA processing unit 302 performs UCR processing and UCA processing to convert a CMY image into a CMYK version image (CMYK image). The UCR process is a process for replacing an equal amount of CMY with K, and the UCA process is a process for adding a constant CMY to K replaced with CMY.

  The printer γ processing unit 303 reads an arbitrary γ process such as a γ process for correcting the plotter characteristics and a γ process for intentionally controlling the contrast for each plate image of the CMYK image. It can be used.

  The clear toner adding unit 304 (determination unit) determines the amount of clear toner (hereinafter referred to as CL adhesion amount) according to the glossiness with respect to the density of the CMYK image (hereinafter referred to as input density), and determines the determined CL adhesion. A CMYKCL image is created by adding a clear toner signal indicating the amount to the CMYK image.

  FIG. 4 is a diagram showing glossiness characteristics in which input density and glossiness are associated with each other. The glossiness characteristics shown in FIG. 4 indicate the relationship between the input density and the glossiness when a CMYK image that has been subjected to gradation processing according to the plotter characteristics (imaging conditions) is output. As shown in FIG. 4, in the glossiness characteristic, the glossiness is improved as the white portion where the dot pattern is not formed (input density is 0) and the solid portion where the dot pattern is buried (input density is 255). . Note that the glossiness characteristic shown in FIG. 4 has a peak glossiness in the solid portion, but may have a peak glossiness in the white portion depending on the plotter characteristics.

  As described above, since the glossiness characteristic is determined by the plotter characteristic and the gradation processing, it is necessary to manage the CL adhesion amount with respect to this glossiness characteristic. Therefore, in the present embodiment, the CMYK image has a CL adhesion amount table (shown in FIG. 5) indicating the input density of the CMYK image subjected to gradation processing according to the plotter characteristics, and the CL adhesion quantity corresponding to the glossiness with respect to the input density. The CL adhesion amount is managed by creating each image version. FIG. 5 is a diagram illustrating a CL adhesion amount table.

Therefore, in this embodiment, the clear toner adding unit 304 determines the CL adhesion amount for each plate of the CMYK image. Therefore, the CL adhesion amount of a certain pixel is
CL = CL_c + CL_m + CL_y + CL_k
And

Also, depending on the calibration pattern (gradation processing pattern), there are overlapping plates, so the CL adhesion amount of a pixel in that case is
CL = MAX (CL_c + CL_m + CL_y + CL_k)
By doing so, it may be possible to prevent unnecessary use of toner.

  The total amount regulating unit 305 (a weight reducing unit) performs a total amount regulating process on the CMYKCL image. The total amount restriction process reflects process restrictions, and in order to prevent fixing failure, the amount of clear toner indicated by the clear toner signal added to the CMYKCL image and the color material of CMYK that reproduces the CMYKCL image. When the total amount exceeds the preset total amount regulation value, gradation processing is performed on the CMYKCL image, and the amount of clear toner indicated by the clear toner signal added to the CMYKCL image and the CMYK image that reproduces the CMYKCL image This is a process for reducing the amount of the color material.

For example, the total amount regulation unit 305, when the total amount (Max = C ′ + M ′ + Y ′ + K ′ + CL) exceeds the total amount regulation value (Max_toner) (Max> Max_toner),
C ″ = (C ′ * (Max_toner−K ′)) / (C ′ + M ′ + Y ′ + CL)
M ″ = (M ′ * (Max_toner−K ′)) / (C ′ + M ′ + Y ′ + CL)
Y ″ = (Y ′ * (Max_toner−K ′)) / (C ′ + M ′ + Y ′ + CL)
K ″ = K ′
CL ″ = Max_toner-C ″ -M ″ -Y ″ -K ″
And

The weight loss of each plate is
ΔC = C′−C ″
ΔM = M′−M ″
ΔY = Y′−Y ″
ΔK = K′−K ″
ΔCL = CL−CL ″
It becomes.

  The adaptive CLγ processing unit 306 (correction unit) obtains C ″, M ″, Y ″, K ″, CL ″ (the color material for reproducing the CMYKCL image after reducing the total amount). Amount) is corrected so as to maintain a uniform glossiness.

Specifically, the adaptive CLγ processing unit 306 first refers to the CL adhesion amount table shown in FIG. 5 and applies the CL adhesion according to the glossiness with respect to the input density of the CMYKCL image after reducing the amount of the CMYK color material. The quantity (CL ″ ″) is determined. Next, the adaptive CLγ processing unit 306 determines a difference (ΔCL_t) between the determined CL ″ and the CL adhesion amount (CL ″) indicated by the clear toner signal added to the CMYKCL image after the decrease.
ΔCL_t = CL ″ ″ − CL ″

  Then, the adaptive CLγ processing unit 306, when ΔCL_t = 0 (C ″ ″, M ″ ″, Y ″ ″, K ″ ″, CL ″ ″ = C ″, M ″, Y ′). ′, K ″, CL ″), and the CMYKCL image after the weight reduction is in a state where the glossiness is maintained, no particular correction is performed.

  On the other hand, when ΔCL_t> 0 (when CL ″ is less than CL ″), the adaptive CLγ processing unit 306 lacks the amount of the CMYKCL image after the reduction relative to the amount of the color material that makes the gloss level uniform. Therefore, correction processing A is performed to reduce the amount of CMYK color material (C ″, M ″, Y ″) that reproduces the CMYKCL image after the reduction.

  In addition, when ΔCL_t <0 (when CL ″ is greater than CL ″), the adaptive CLγ processing unit 306 has a surplus with respect to the amount of the color material that makes the glossiness uniform in the CMYKCL image after reduction. Therefore, the correction process B for increasing the amount of CMYK color material (C ″, M ″, Y ″) for reproducing the CMYKCL image after the reduction is performed.

  Here, the correction process A will be described in detail. First, the adaptive CLγ processing unit 306 uses the color material simulation, and CMYK color material amounts and CL adhesion amounts (C ′, M ′, Y ′, K ′, CL) for reproducing the CMYKCL image before the total amount restriction processing. The chromaticity value L1 * a1 * b1 * is calculated.

  As a method for calculating the chromaticity value L1 * a1 * b1 *, for example, a color material simulation is created in advance using a known technique such as a multiple regression analysis method or a neural network method that is well known as a black box model in a halftone model. The chromaticity value L1 * a1 * b1 * may be determined using the color material simulation.

  Further, the adaptive CLγ processing unit 306 uses the color material simulation, and the amount of CMYK color material and the amount of CL adhesion (C ″, M ″, Y ″, K) for reproducing the CMYKCL image after the total amount regulation processing. The chromaticity value L2 * a2 * b2 * for “″, CL ″) is calculated.

  FIG. 6 is a diagram illustrating a change example of the chromaticity of the CMYKCL image due to the influence of the total amount restriction process. The chromaticity values a * and b * of the CMYKCL image are both negatively shifted due to the influence of the total amount restriction process. In order for the chromaticity value L2 * a2 * b2 * and the chromaticity value L1 * a1 * b1 * to be close to each other, the amount of CMYK color material must be controlled. There is a restriction that the amount of CMYK color material and the amount of attached CL (C ″, M ″, Y ″, K ″, CL ″) for reproducing the CMYKCL image after reduction must be reduced. Therefore, as a method of reducing the amount of the color material, the amount of CMYK color material that reproduces the CMYKCL image after the decrease and the adhesion of CL by lowering C, lowering M and C and increasing Y, lowering Y, etc. A method of reducing the amount (C ″, M ″, Y ″, K ″, CL ″) can be considered.

  Further, the range in which the amount of the color material can be reduced (hereinafter referred to as a correction request range) is only ΔCL_t. That is, the correction request range is ΔCL_t = (C_ex + M_ex + Y_ex). Accordingly, the adaptive CLγ processing unit 306 can control the amount of the CMYK color material that reproduces the CMYKCL image after the reduction by a total of ΔCL_t. For example, ΔCL_t is defined as follows.

  FIG. 7 is a diagram for classifying which hue region a2 * and b2 * are in when (a *, b *) = (a1 *, b1 *) is the center. The adaptive CLγ processing unit 306 determines a reduction balance of the amount of CMY color material depending on which hue region a2 * and b2 * are in.

  FIG. 8 is a diagram illustrating a reduction balance of the amount of CMY color material in each hue region. The weight loss balance shown in FIG. 8 indicates at what ratio each plate is to be reduced, with ΔCL_t being the total amount of CMY color materials to be reduced. For example, when a2 * and b2 * are in HUEH0, C is not reduced, M is reduced by 40% of ΔCL_t, and Y is reduced by 60% of ΔCL_t.

  As described above, the adaptive CLγ processing unit 306 determines C_ex, M_ex, and Y_ex for each pixel. In this embodiment, C_ex, M_ex, and Y_ex are simply determined. However, in order to make the hue continuity more natural, the number of circuits is increased, and the HUEH attribute information of adjacent pixels is reduced. The color material may be fed back to the determination of the amount of the color material so that the gradation is emphasized.

  Next, the correction process B will be described in detail. In the correction process B, the CL excess Abs (ΔCL_t) and the amount of the CMYK color material may be increased relative to the amount of the color material that makes the glossiness of the CMYKCL image after the reduction uniform.

That is, the amount of increase in the CMY color material (C_add, M_add, Y_add) is in the direction of feeding back the total amount regulation value.
C_add = Abs (ΔCL_t) * (C ″ + M ″ + Y ″)
M_add = Abs (ΔCL_t) * (C ″ + M ″ + Y ″)
Y_add = Abs (ΔCL_t) * (C ″ + M ″ + Y ″)
Can be determined. Since the correction process B is performed when the amount of the CMY color material is excessively decreased, the amount of the CMY color material that has been excessively decreased is increased to bring the CMYKCL image closer to the originally intended chromaticity. be able to.

  As described above, according to the MFP 100 according to the present embodiment, the CL adhesion amount corresponding to the glossiness with respect to the input density of the CMYK image reproduced by the CMYK color material is determined, and the determined CL adhesion amount and the CMYK image are determined. When the total amount of the CMYK color material to be reproduced exceeds a preset total amount regulation value, the CMYK image is subjected to gradation processing, and the determined CL adhesion amount and the CMYK color material amount for reproducing the CMYK image When the CL adhesion amount corresponding to the glossiness with respect to the input density of the CMYK image after reducing the amount of the CMYK color material is smaller than the CL adhesion amount after the reduction, the amount of the CMYK color material is reduced. When the amount of CMYK color material that reproduces the image is reduced, and the amount of CMYK color material is less than the amount of CL adhesion after the reduction, according to the glossiness with respect to the density of the CMYK image after reduction, By increasing the amount of the CMYK color material that reproduces the CMYK image after reducing the amount of the MYK color material, it is possible to prevent the CL adhesion amount from being reduced more than necessary by the total amount control processing. Even if the CL adhesion amount is regulated by the above, it is possible to maintain a certain glossiness and suppress a change in desired color information (shift in brightness or saturation).

  In this embodiment, the amount of CMYK color material that reproduces a CMYK image after reduction is reduced or increased with emphasis on the glossiness of the CMYK image. However, the brightness and saturation of the CMYK image are saved. It is also possible to reduce or increase the amount of the CMYK color material that reproduces the CMYK image after the weight reduction. In this case, it is possible to correct an image with higher accuracy by linking known methods such as brightness preservation and saturation preservation by gamut mapping of the 3DLUT unit 301 with correction in the adaptive CLγ processing unit 306. For example, when the 3DLUT unit 301 performs lightness preservation, the adaptive CLγ processing unit 306 also attaches importance to lightness preservation, and reduces or increases the amount of the CMYK color material that reproduces the reduced CMYK image.

(Second Embodiment)
In this embodiment, the character part and the picture part of the RGB image are detected, and the CL adhesion amount corresponding to the glossiness with respect to the input density of the CMYK image reproduced by the color material of CMYK is applied to each of the detected character part and the picture part. It is an example to determine. Note that the description of the same parts as those of the MFP 100 according to the first embodiment is omitted, and only the parts different from those of the MFP 100 according to the first embodiment will be described.

  FIG. 9 is a block diagram showing a specific configuration of the image data processing apparatus. The image data processing apparatus 900 includes an image area separation processing unit 901, a scanner γ conversion unit 201, a filter processing unit 202, a toner control processing unit 902, a scaling compression unit 205, a compression processing unit 206, a gradation processing unit 207, and the like. .

  The image area separation processing unit 901 (detection unit) detects a character part and a picture part from the RGB image by extracting feature values of the input RGB image, and detects the character part and the picture part in the RGB image. Detection information is added as incidental information.

  The printer γ processing unit 903 (clear toner adding unit 304) included in the toner control processing unit 902 calculates the CL adhesion amount according to the glossiness with respect to the input density of the CMYK image converted from the RGB image in the UCR / UCA processing unit 302. A CMYKCL image is created by determining the character part and the picture part indicated by the detection information added to the CMYK image, and adding a clear toner signal indicating the CL adhesion amount of the decided character part and picture part to the CMYK image.

  For example, when the glossiness is improved only in the character part, the clear toner adding unit 304 determines the CL adhesion amount only in the character part, and adds a clear toner signal indicating the determined CL adhesion amount of the character part. Create Further, the total amount restriction unit 305 performs a total amount restriction process on the character part of the CMYKCL image, and the adaptive CLγ processing unit 306 further determines the amount of the color material that reproduces the character part of the CMYKCL image after reducing the total amount. Correct in a direction to maintain uniform gloss. When the glossiness is improved only in the character part, the CL toner amount of the pattern part is not determined in the clear toner adding part 304 and the correction in the adaptive CLγ processing part 306 is not performed, and only the total amount restricting part 305 has the picture of the CMYK image. It is assumed that the total amount restriction process is performed on the part. As a result, the glossiness of only the character portion is improved to improve the character quality, and the clear toner is not attached to the pattern portion, thereby reducing the amount of clear toner used.

  When the glossiness is improved only in the pattern portion, the clear toner adding unit 304 determines the CL adhesion amount only in the pattern portion, and adds a CMYKCL image to which the clear toner signal indicating the determined CL adhesion amount of the pattern portion is added. Create Further, the total amount restriction unit 305 performs total amount restriction processing on the pattern portion of the CMYKCL image, and the adaptive CLγ processing unit 306 performs total amount restriction processing on the pattern portion of the CMYKCL image after the reduction of the total amount, Further, the adaptive CLγ processing unit 306 corrects the amount of the color material that reproduces the pattern portion of the CMYK image after reducing the total amount in a direction in which uniform glossiness is maintained. When the glossiness is improved only in the pattern portion, the CL toner amount is not determined in the clear toner adding portion 304 and the adaptive CLγ processing portion 306 is not corrected, and only the total amount restricting portion 305 is the character in the CMYK image. It is assumed that the total amount restriction process is performed on the part. As a result, even when it is desired to give more importance to the glossiness of the pattern portion, such as when copying photographic paper, the amount of clear toner used can be reduced.

(Third embodiment)
The present embodiment detects the glossiness of the output gradation pattern, creates a glossiness characteristic in which the detected glossiness is associated with the input density of the gradation pattern, and creates the input density of the gradation pattern In this glossiness characteristic, an adhesion amount table is created in which the CL adhesion amount corresponding to the glossiness associated with the input density of the gradation pattern is associated with the input density of the CMYK image in the created adhesion amount table. This is an example in which the obtained CL adhesion amount is determined as a CL adhesion amount to be adhered to a CMYK image reproduced by a CMYK color material. Note that the description of the same parts as those of the MFP 100 according to the first embodiment is omitted, and only the parts different from those of the MFP 100 according to the first embodiment will be described.

  FIG. 10 is a schematic diagram showing the configuration of the reading device. In this embodiment, an example in which the double-sided simultaneous reading device is applied to the reading device 1000 will be described. However, the present invention is not limited to the double-sided simultaneous reading device.

  Inside the reading apparatus 1000, a first traveling body 1112 including a light source 1111 that can arbitrarily change the exposure amount composed of a xenon lamp or a fluorescent lamp, a white plate 1110 that receives exposure, and a mirror 1113, Second traveling body 1115 provided with mirrors 1114 and 1116, lens 1117, one-dimensional photoelectric conversion device (CCD) 1118, sheet-through document feeder (SDF) unit 1104, and document table 1101 A white reference plate 1107, a back surface reading lamp 1108, a contact sensor 1109, and a glossiness detection unit 1120. It is assumed that the SDF unit 1104 is provided on the upper part of the document pressing plate provided in the reading apparatus 1000.

  When the stepping motor 1106 controlled by the CPU 105 is driven, the SDF unit 1104 transports the document 1100 set on the document table 1101 via the separation roller 1102 and the transport roller 1105, and the first traveling body. 1111 is conveyed to a predetermined reading position. At that time, the document 1100 is conveyed at a constant speed, and the first traveling body 1112 reads digital image data of the document surface of the document 1100 in a stopped state by the CCD 1118. At the time of double-sided reading, the SDF unit 1104 reads the white reference plate 1107 by the CCD 1118, then irradiates the back side of the original 1100 with light from the back side reading lamp 1108, reads the reflected light with the contact sensor 1109, and outputs digital image data. obtain. Thereby, digital image data of the front and back sides of the document can be obtained simultaneously.

  The glossiness detection unit 1120 (detection unit) detects the glossiness of the gradation pattern printed on the recording medium (original 1100). FIG. 11 is a schematic diagram illustrating the configuration of the glossiness detection unit. The glossiness detection unit 1120 includes a light emitting unit 10a made of a tungsten filament lamp or the like, a light receiving unit 10b made of a photodiode element, or the like. Then, the recording medium P is irradiated with the light emitted from the light emitting unit 10a at the incident angle θ1 (60 °), and the regular reflection light reflected at the emission angle θ2 (60 °) is received by the light receiving unit 10b. Then, the glossiness (60 degree glossiness) of the recording medium P is detected based on the magnitude of the regular reflection light received by the light receiving unit 10b.

  A process for determining the CL adhesion amount in the multifunction machine 100 including the above-described glossiness detection unit 1120 will be described below.

  First, the CPU 105 (output unit) outputs a CMYK color material gradation pattern (shown in FIG. 12) from the plotter device 108 via the plotter I / F device 107. FIG. 12 is a diagram showing a gradation pattern of CMYK color materials.

  Next, the CPU 105 passes the document 1100 printed with the gradation pattern output from the plotter device 108 to the reading device 1000, and the glossiness detection unit 1120 detects the glossiness of the gradation pattern of the CMYK color material. . Further, the CPU 105 obtains the digital image data of the gradation pattern of the CMYK color material by the CCD 1118 and calculates the input density of the digital image data.

Since the CCD 1118 obtains digital image data displayed in RGB, the input density of the digital image data can be defined as follows from tristimulus values XYZ determined from RGB.
C = X * α_c + Y * β_c + Z * γ_c
M = X * α_m + Y * β_m + Z * γ_m
Y = X * α_y + Y * β_y + Z * γ_y
K = X * α_k + Y * β_k + Z * γ_k
Note that α, β, and γ of each version of CMYK are determined by spectral characteristics when the CCD 1118 receives light.

  Next, the CPU 105 (first creation unit) associates the glossiness of the CMYK gradation pattern detected by the glossiness detection unit 112 with the input density of the calculated digital image data (CMYK gradation pattern). Glossiness characteristics (shown in FIG. 4) are created.

  If the glossiness characteristics are stored in advance in the HDD 104, the CPU 105 updates the glossiness characteristics stored in the HDD 104 with the created glossiness characteristics. By updating the glossiness characteristic at the time of calibration of the multifunction peripheral 100, a glossiness characteristic that takes into account the glossiness of the document 1100 can be created.

  Further, the CPU 105 (second creation unit) determines the input density of the CMYK gradation pattern and the CL adhesion amount corresponding to the glossiness associated with the input density of the CMYK gradation pattern in the created glossiness characteristic. An associated adhesion amount table is created.

  The clear toner addition unit 304 uses the CL adhesion amount associated with the input density of the CMYK image in the created adhesion amount table as the CL adhesion amount according to the glossiness with respect to the input density of the CMYK image reproduced by the CMYK color material. Shall be determined.

  In general, the glossiness of paper varies and is unique depending on the paper type. For this reason, the input density of the CMYK image is influenced by the glossiness of the paper, particularly at a gradation close to that of blank paper. For this reason, the desired glossiness characteristic changes according to the paper used by the user of the multifunction peripheral 100.

  Therefore, in the present embodiment, the glossiness of the output CMYK gradation pattern is detected, and a glossiness characteristic in which the detected glossiness is associated with the input density of the CMYK gradation pattern is created. An adhesion amount table that associates the input density of the tone pattern with the CL adhesion amount according to the glossiness associated with the input density of the CMYK gradation pattern in the created glossiness characteristic, and creates the created adhesion amount By determining the CL adhesion amount associated with the input density of the CMYK image in the table as the CL adhesion amount according to the glossiness with respect to the input density of the CMYK image reproduced by the CMYK color material, a desired gloss depending on the paper Since the degree characteristic can be changed, it is possible to determine the CL adhesion amount more suited to the user's environment.

(Fourth embodiment)
In this embodiment, a different adhesion amount table is created for each of the character part and the pattern part of the CMYK image, and the CL associated with the input density of the character part or the pattern part in the created character part or pattern part adhesion amount table. In this example, the adhesion amount is determined as the CL adhesion amount according to the glossiness with respect to the input density of the character portion or the pattern portion. Note that the description of the same parts as those of the MFP 100 according to the third embodiment is omitted, and only the parts different from those of the MFP 100 according to the third embodiment will be described.

  First, when the image data processing apparatus 102 includes the image area separation processing unit 901, the character part and the picture part can be detected from the RGB image, so that the image processing can be changed between the character part and the picture part. For example, in the tone processing of the character part, an error diffusion process is performed so that the character reproduction is improved, and in the tone processing of the pattern part, a dither process is performed. Image processing is possible.

  By the way, when the dot pattern changes, the gradation characteristics and graininess change according to the dot pattern, so the glossiness also changes accordingly. Therefore, it is desirable to create glossiness characteristics according to the dot pattern.

  Therefore, the CPU 105 (output unit), via the plotter I / F device 107, performs the first CMYK gradation pattern (shown in FIG. 13) and the pattern part subjected to the gradation process (error diffusion process) of the character part. The CMYK second gradation pattern (shown in FIG. 13) subjected to the gradation processing (error diffusion processing) is output from the plotter device 108. FIG. 13 is a diagram illustrating a first gradation pattern and a second gradation pattern.

  Next, the CPU 105 passes the original 1100 printed with the first gradation pattern and the second gradation pattern output from the plotter device 108 to the reading device 1000, and the glossiness detection unit 1120 generates the first gradation pattern. The glossiness and the glossiness of the second gradation pattern are detected. Further, the CPU 105 obtains the digital image data of the first gradation pattern and the digital image data of the second gradation pattern by the CCD 1118, and calculates the input density of the digital image data. Note that the method for calculating the input density of the digital image data for each of the first gradation pattern and the second gradation pattern is the same as in the third embodiment.

  Next, the CPU 105 (first creation unit) associates the glossiness of the first gradation pattern detected by the glossiness detection unit 112 with the calculated input density of the first gradation pattern. Create Further, the CPU 105 creates a second glossiness characteristic in which the glossiness of the second gradation pattern detected by the glossiness detection unit 112 is associated with the calculated input density of the second gradation pattern.

  Further, the CPU 105 (second creation unit) determines the CL adhesion amount according to the input density of the first gradation pattern and the glossiness associated with the input density of the first gradation pattern in the created first glossiness characteristic. The first adhesion amount table is created in accordance with the input density of the first gradation pattern and the glossiness associated with the input density of the first gradation pattern in the created second glossiness characteristic. A second adhesion amount table in which the CL adhesion amount is associated is created.

  Then, the clear toner adding unit 304 uses the CL adhesion amount associated with the input density of the character portion in the first adhesion amount table created by the CPU 105 as the CL adhesion amount according to the glossiness with respect to the input density of the character portion. Further, the CL adhesion amount associated with the input density of the pattern portion in the second adhesion amount table created by the CPU 105 is determined as the CL adhesion amount according to the glossiness with respect to the input density of the pattern portion.

  As described above, according to the multifunction peripheral 100 according to the present embodiment, different adhesion amount tables are created for the character portion and the pattern portion of the CMYK image, and the character portion or the pattern in the created character portion or the attachment amount table of the pattern portion. By determining the CL adhesion amount associated with the input density of the portion as the CL adhesion amount according to the glossiness with respect to the input density of the character portion or the pattern portion, an appropriate CL adhesion amount for each of the character portion and the pattern portion is determined. Therefore, the clear toner can be more appropriately attached to the character portion and the pattern portion.

  Note that the program executed by the MFP 100 according to the above-described embodiment is provided by being incorporated in advance in a ROM or the like.

  The program executed by the multifunction peripheral 100 of the above-described embodiment is a file in an installable format or an executable format, and is a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk). For example, the program may be recorded on a computer-readable recording medium.

  Furthermore, the program executed by the MFP 100 according to the above-described embodiment may be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. In addition, the program executed by the MFP 100 according to the above-described embodiment may be provided or distributed via a network such as the Internet.

  The program executed by the MFP 100 according to the above-described embodiment includes the above-described units (decision unit, weight reduction unit, correction unit, detection unit, detection unit, output unit, first creation unit, second creation unit, and the like). As the actual hardware, the CPU 105 (processor) reads out the program from the ROM and executes it to load each of the above units on the main storage device. The determining unit, the reducing unit, the correcting unit, A detection unit, a detection unit, an output unit, a first creation unit, a second creation unit, and the like are generated on the main storage device.

100 MFP 102,900 Image Data Processing Device 105 CPU
300, 902 Toner control processing unit 203 Color correction unit 204, 903 Printer γ processing unit 304 Clear toner addition unit 305 Total amount regulating unit 306 Adaptive CLγ processing unit 901 Image area separation processing unit 1120 Gloss degree detection unit

JP 2007-183593 A

Claims (9)

Determining means for determining the amount of clear toner in accordance with the glossiness with respect to the density of the image reproduced by the colored toner;
When the total amount of the determined amount of clear toner and the amount of colored toner that reproduces the image exceeds a preset total amount regulation value, gradation processing is performed on the image, and the determined amount of clear toner and A weight reducing means for reducing the amount of the colored toner for reproducing the image;
When the amount of clear toner corresponding to the glossiness with respect to the density of the image after reducing the amount of color toner is less than the amount of clear toner after reduction, the amount of color toner that reproduces the image after reducing the amount of color toner If the amount of the clear toner corresponding to the glossiness with respect to the density of the image after the reduction of the color toner is larger than the amount of the clear toner after the reduction, the amount of the color toner is reduced. Correction means for increasing the amount of colored toner to be reproduced;
An image processing apparatus comprising: It further comprises detection means for detecting a character part and a picture part of the image,
The image processing apparatus according to claim 1, wherein the determining unit determines the amount of clear toner corresponding to the glossiness with respect to the density of the image for each of the detected character portion and pattern portion. An output means for outputting a gradation pattern of the colored toner;
Detecting means for detecting the glossiness of the gradation pattern output by the output means;
A first creation means for creating a glossiness characteristic in which the detected glossiness and the density of the gradation pattern are associated with each other;
A second creation unit that creates an adhesion amount table that associates the density of the gradation pattern with the amount of clear toner corresponding to the glossiness associated with the density of the gradation pattern in the glossiness characteristic; Further comprising
2. The determination unit according to claim 1, wherein the amount of the clear toner associated with the image density in the adhesion amount table is determined as the amount of the clear toner corresponding to the glossiness with respect to the image density. Or the image processing apparatus of 2. Output means for outputting a first gradation pattern of colored toner subjected to gradation processing of a character portion and a second gradation pattern of colored toner subjected to gradation processing of a pattern portion;
Detecting means for detecting the glossiness of the first gradation pattern and the glossiness of the second gradation pattern output by the output means;
A first gloss characteristic that associates the detected glossiness of the first tone pattern with the density of the first tone pattern, and the detected glossiness of the second tone pattern and the second tone pattern. First creating means for creating a second glossiness characteristic in association with the density of
A first adhesion amount table associating the density of the first gradation pattern with the amount of clear toner corresponding to the glossiness associated with the density of the first gradation pattern in the first glossiness characteristic; And a second adhesion amount table in which the density of the second gradation pattern and the amount of clear toner corresponding to the glossiness associated with the density of the second gradation pattern in the second glossiness characteristic are associated with each other. A second creation means for creating
The determining means determines the amount of the clear toner associated with the detected character portion density in the first adhesion amount table as the amount of the clear toner corresponding to the glossiness with respect to the detected character portion density. The amount of clear toner associated with the detected density of the pattern portion in the second adhesion amount table is determined as the amount of clear toner corresponding to the glossiness with respect to the detected density of the pattern portion. The image processing apparatus according to claim 2. An image processing method executed by an image processing apparatus,
The image processing apparatus includes:
A determining step for determining the amount of the clear toner according to the glossiness with respect to the density of the image reproduced by the colored toner;
When the total amount of the determined amount of clear toner and the amount of colored toner that reproduces the image exceeds a preset total amount regulation value, the reducing unit performs gradation processing on the image and performs the determined clear toner A weight reduction step for reducing the amount of toner and the amount of colored toner that reproduces the image;
When the amount of the clear toner corresponding to the glossiness with respect to the density of the image after reducing the amount of the colored toner is smaller than the amount of the clear toner after the reduction, the correcting unit reproduces the image after reducing the amount of the colored toner. When the amount of the color toner is reduced, and the amount of the clear toner corresponding to the glossiness with respect to the density of the image after the amount of the color toner is reduced is larger than the amount of the clear toner after the reduction, the amount of the color toner is reduced. A correction process for increasing the amount of colored toner that reproduces the later image;
An image processing method comprising: The detection means further includes a detection step of detecting a character part and a picture part of the image,
6. The image processing method according to claim 5, wherein the determining step determines the amount of clear toner corresponding to the glossiness with respect to the density of the image for each of the detected character portion and pattern portion. An output step in which the output means outputs a gradation pattern of the colored toner;
A detecting step for detecting a glossiness of the output gradation pattern;
A first creating step for creating a glossiness characteristic in which the first creating means associates the detected glossiness with the density of the gradation pattern;
The second creating means creates an adhesion amount table in which the density of the gradation pattern is associated with the amount of clear toner corresponding to the glossiness associated with the density of the gradation pattern in the glossiness characteristic. A second creation step,
6. The determining step, wherein the amount of clear toner associated with the density of the image in the adhesion amount table is determined as the amount of clear toner corresponding to the glossiness with respect to the density of the image. Or the image processing method of 6. An output step of outputting a first gradation pattern of the colored toner on which the gradation processing of the character portion has been performed and a second gradation pattern of the colored toner on which the gradation processing of the pattern portion has been performed;
A detecting step for detecting a glossiness of the output first gradation pattern and a glossiness of the output second gradation pattern;
The first creation means includes a first glossiness characteristic that associates the detected glossiness of the first gradation pattern with the density of the first gradation pattern, and the detected glossiness of the second gradation pattern. A first creation step of creating a second glossiness characteristic that associates the density of the second gradation pattern;
The second creating means associates the density of the first gradation pattern with the amount of clear toner corresponding to the glossiness associated with the density of the first gradation pattern in the first glossiness characteristic. The first adhesion amount table and the density of the second gradation pattern are associated with the amount of clear toner corresponding to the glossiness associated with the density of the second gradation pattern in the second glossiness characteristic. A second creation step of creating a second adhesion amount table,
In the determining step, the amount of the clear toner associated with the detected density of the character portion in the first adhesion amount table is determined as the amount of the clear toner corresponding to the glossiness with respect to the detected density of the character portion. The amount of clear toner associated with the detected density of the pattern portion in the second adhesion amount table is determined as the amount of clear toner corresponding to the glossiness with respect to the detected density of the pattern portion. The image processing method according to claim 6.   A program for causing a computer to execute the image processing method according to any one of claims 5 to 8.

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