Image formation apparatus, image formation method, and program

Abstract

To provide an image formation apparatus which causes attachment of a color material of a proper color material amount onto a recording medium, and prevents the recording medium from becoming unclear.SOLUTION: An image formation apparatus includes: a color information acquisition section for acquiring color information indicating a color value, for each pixel in a target area composed of target pixels among a plurality of constituting pixels and at least one reference pixel different from the target pixels among the plurality of pixels; a determination section for determining whether or not to apply color material total amount regulation of a color material to be attached with regard to the target pixels, on the basis of the color information; and an image formation section for forming an image on a recording medium by attaching a color material to the recording medium according to a determination result of the determination section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus, an image forming method, and a program. [Background technology]

[0002] Patent document 1 discloses a technique for determining whether the total amount of color materials falls within a predetermined total amount regulated value based on the density value of each color after gradation correction, and if the total amount of color materials based on the density value of each color after gradation correction is equal to or greater than the total amount regulated value, uniformly increasing or decreasing the density value of each CMYK color component before gradation correction until the total amount of color materials falls within the predetermined total amount regulated value.

[0003] Patent document 2 discloses a technology in which the sum of the C, M, Y, and K values ​​of each pixel is updated to the amount of usable ink based on a weight parameter calculated based on the relative weights of saturation and darkness and a total ink amount regulated value according to the recording medium, and then pseudo-toning is performed on the updated CMYK data to create print data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-125225 A [Patent Document 2] JP 2006-281445 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the techniques disclosed in Patent Documents 1 and 2, the total amount of coloring material is restricted for each pixel. Therefore, in the techniques described in Patent Documents 1 and 2, when the total amount of coloring material is restricted for a relatively small area, the area may become unclear on the recording medium on which an image is formed. Therefore, an object of one aspect of the present disclosure is to provide an image forming apparatus, an image forming method, and a program that can apply an appropriate amount of coloring material to a recording medium and prevent the image from becoming unclear. [Means for solving the problem]

[0006] An image forming apparatus according to one embodiment of the present disclosure includes a color information acquisition unit that acquires color information indicating a color value for each pixel of a region of interest consisting of a pixel of interest among a plurality of pixels constituting an image and at least one reference pixel different from the pixel of interest among the plurality of pixels, a judgment unit that judges based on the color information whether or not to apply a total amount restriction on color material to be applied to the pixel of interest, and an image forming unit that applies color material to a recording medium based on a judgment result by the judgment unit to form the image on the recording medium.

[0007] An image forming method according to one embodiment of the present disclosure includes a color information acquisition step of acquiring color information indicating a color value for each pixel of a region of interest consisting of a pixel of interest among a plurality of pixels constituting an image and at least one reference pixel different from the pixel of interest among the plurality of pixels, a determination step of determining based on the color information whether or not to apply a total amount restriction on color material to be applied to the pixel of interest, and an image forming step of applying color material to a recording medium based on a determination result by the determination step to form the image on the recording medium.

[0008] A program according to one embodiment of the present disclosure causes a computer to execute a color information acquisition function that acquires color information indicating a color value for each pixel of a region of interest consisting of a pixel of interest among a plurality of pixels that constitute an image and at least one reference pixel different from the pixel of interest among the plurality of pixels, a judgment function that judges based on the color information whether or not to apply a total color material amount restriction on the color material to be attached to the pixel of interest, and an image formation function that attaches color material to a recording medium based on a judgment result by the judgment function to form the image on the recording medium. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an example of a configuration of an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 4 is a diagram illustrating an example of color material total amount management information. [Diagram 3] 5 is a flowchart showing an example of an operation of the image forming apparatus according to the first embodiment. [Figure 4] 1 is a diagram showing an example of a pixel region to which a total color material amount restriction is applied; [Diagram 5] 10 is a flowchart showing an example of an operation of an image forming apparatus according to a second embodiment. [Figure 6] A figure showing an object included in an image output when the total color material amount restriction is not applied, an example of an object included in an image output by an image forming device related to a first embodiment, and an example of an object included in an image output by an image forming device related to a second embodiment. [Figure 7] FIG. 13 is a block diagram showing an example of a configuration of an image forming apparatus according to a fourth embodiment. [Figure 8A] 11 is a graph showing an example of the relationship between the color difference from paper white, the amount of adhesion, and the color information value of an output color channel. [Figure 8B] 11 is a graph showing an example of the relationship between the color information value of an output color channel and the amount of adhesion. [Figure 9] 13 is a flowchart showing an example of an operation of an image forming apparatus according to a fourth embodiment. [Figure 10A] 13 is a flowchart showing an example of an operation of an image forming apparatus according to a fifth embodiment. [Figure 10B] 10B is a flowchart showing an example of the operation of the image forming apparatus according to the fifth embodiment, subsequent to FIG. 10A. [Figure 11A] FIG. 4 is a diagram showing an example of an area where a coloring material is attached to a recording medium. [Figure 11B] FIG. 4 is a diagram showing an example of an area where a coloring material is attached to a recording medium. [Figure 12A] 13A and 13B are diagrams illustrating an example of a relationship between a pixel of interest and pixels other than the pixel of interest in a region of interest in an image forming apparatus according to a seventh embodiment. [Figure 12B] FIG. 13 is a diagram showing an example of a recording medium on which printer's marks for managing printed products are printed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment A first embodiment will be described with reference to Figures 1 to 4. In the drawings, the same or similar elements are given the same reference numerals, and duplicated explanations will be omitted.

[0011] 1 is a block diagram showing an example of the configuration of an image forming apparatus 100 according to this embodiment. The image forming apparatus 100 includes a display unit 101, an operation unit 102, an image input unit 103, an image forming unit 104, an image output unit 105, a storage unit 106, and a control unit 107.

[0012] The display unit 101 displays information to be presented to a user. For example, the display unit 101 is configured with a liquid crystal panel, an organic EL (Electro-Luminescence) panel, or the like.

[0013] The operation unit 102 receives operations from a user and is configured with, for example, hard keys, buttons, a touch panel, and the like.

[0014] The image input unit 103 receives input of image information 111. The image information 111 indicates pixel values ​​of a plurality of pixels that form an image 113.

[0015] Alternatively, the image input unit 103 may receive an input of a printed document and generate image information 111 from the input printed document. For example, when the image input unit 103 receives an input of a printed document, the image input unit 103 generates image information 111 by reading the printed document with an image sensor such as a CCD (Charged Coupled Device) or a CIS (Contact Image Sensor).

[0016] Furthermore, the image input unit 103 accepts input of recording medium information 112. The recording medium information 112 indicates the type of recording medium, etc. For example, the type of recording medium is the type of paper.

[0017] The image forming unit 104 adheres coloring material to the recording medium to form an image 113 based on the image information 111 on the recording medium. For example, the image forming unit 104 can be configured as a laser printer using an electrophotographic method, or an inkjet printer using an inkjet method. When the image forming unit 104 is configured as a laser printer, it adheres toner, which is a coloring material, to the recording medium to form an image 113 on the recording medium. When the image forming unit 104 is configured as an inkjet printer, it adheres ink, which is a coloring material, to the recording medium to form an image 113 on the recording medium.

[0018] The image output unit 105 outputs the recording medium on which the image 113 is formed. That is, the image output unit 105 outputs the recording medium on which the image 113 is printed.

[0019] The storage unit 106 is a recording medium capable of recording various data, programs, etc. Specifically, the storage unit 106 stores color material total amount management information 114 (see FIG. 2).

[0020] The control unit 107 executes various processes according to the programs and data stored in the storage unit 106. For example, the control unit 107 is configured with a processor such as a CPU (Central Processing Unit). The control unit 107 includes a color information acquisition unit 121, a determination unit 122, and a total amount restriction unit 123.

[0021] The color information acquisition unit 121 acquires color information 115 indicating a color value for each pixel of a target region R consisting of a target pixel P among the multiple pixels constituting the image 113 and at least one reference pixel P2 different from the target pixel P1 among the multiple pixels constituting the image 113. For example, the color value indicated by the color information 115 indicates the color density.

[0022] The determination unit 122 determines whether or not to apply the total color material amount restriction for the color material to be applied to the pixel of interest P1 based on the color information 115. That is, the determination unit 122 determines whether or not to restrict the amount of color material to be applied to the pixel of interest P1 based on the color information 115. Specifically, when a first representative value V1 of the color value indicated by the color information 115 acquired for the pixel of interest P1 and at least one reference pixel P2 is greater than a total color material amount restriction value TH set according to the recording medium, the determination unit 122 determines that the total color material amount restriction is to be applied to the pixel of interest P1. On the other hand, when the first representative value V1 is equal to or less than the total color material amount restriction value TH, the determination unit 122 determines that the total color material amount restriction is not to be applied to the pixel of interest P1. For example, the first representative value V1 is an average value of the color value indicated by the color information 115 acquired for the pixel of interest P1 and at least one reference pixel P2.

[0023] When it is determined that the total color material amount restriction is to be applied to the pixel of interest P1, the total amount restriction unit 123 sets the total color material amount restriction based on the total color material amount restriction value TH, and applies the total color material amount restriction to the pixel of interest P1. Specifically, when it is determined that the total color material amount restriction is to be applied to the pixel of interest P1, the total amount restriction unit 123 restricts the amount of color material used for the pixel of interest P1 to be equal to or less than the total color material amount restriction value TH.

[0024] FIG. 2 is a diagram showing an example of the color material total amount management information 114. As shown in FIG.

[0025] When the image forming unit 104 forms an image 113 by applying color materials to a recording medium, the adhesive strength of the color materials differs depending on the type of recording medium. Therefore, the appropriate total amount of color materials differs depending on the type of recording medium. Therefore, the type of recording medium and the total color material amount limit value TH are registered in association with each other in the total color material amount management information 114.

[0026] For example, the color material total amount limit TH indicates the upper limit of the amount of color material in a unit area, which is set to prevent poor fixing and wrapping caused by the recording medium with the color material adhering to the roller that transports the recording medium. For example, when the recording medium is colored by depositing multiple color materials on the recording medium in layers, the color material total amount limit TH indicates the total value of the concentration of the multiple color materials.

[0027] For example, the type of recording medium, which is plain paper, is associated with the total color material amount limit value TH, which is TH1, and is registered in the total color material amount management information 114. Also, for example, the type of recording medium, which is glossy paper, is associated with the total color material amount limit value TH, which is TH2, and is registered in the total color material amount management information 114.

[0028] FIG. 3 is a flowchart showing an example of the operation of the image forming apparatus 100 according to the present embodiment.

[0029] In step S301, the image input unit 103 receives the input of the image information 111, thereby acquiring the image information 111.

[0030] In step S302, the image input unit 103 receives the input of the recording medium information 112, thereby acquiring the recording medium information 112.

[0031] In step S303, the color information acquisition unit 121 identifies a color material total amount limit value TH corresponding to the type of recording medium. Specifically, the color information acquisition unit 121 identifies a color material total amount limit value TH associated with the type of recording medium indicated by the recording medium information 112 in the color material total amount management information 114.

[0032] In step S304, the color information acquisition unit 121 selects a pixel of interest P1 from the multiple pixels indicated by the image information 111 acquired in step S301.

[0033] In step S305, the color information acquisition unit 121 acquires color information 115 for each pixel in a region of interest R consisting of a pixel of interest P1 and at least one reference pixel P2. The color information 115 indicates a color value of each pixel in the region of interest R. For example, the color value indicated by the color information 115 indicates a color density. The color density may be indicated by the density of a color material applied to a recording medium.

[0034] In step S306, the determination unit 122 calculates a first representative value V1 of the color information 115. For example, the first representative value V1 is the average value of the color values ​​indicated by the color information 115. In this case, the first representative value V1 is the average value of the density of the color material adhered to the recording medium within the region of interest R.

[0035] In step S307, the determination unit 122 determines whether the first representative value V1 is greater than the color material total amount restriction value TH specified in step S303. If the first representative value V1 is equal to or less than the color material total amount restriction value TH in step S307, the total amount restriction unit 123 does not apply color material total amount restriction to the pixel of interest P1 in step S308. In this case, the total amount restriction unit 123 determines the color material amount C1 at the position of the pixel of interest P1 from the color value indicated by the color information 115 for the pixel of interest P1. Then, the control unit 107 proceeds to step S310.

[0036] On the other hand, if the first representative value V1 is greater than the color material total amount limit value TH in step S307, the total amount limiting unit 123 applies a color material total amount limit to the pixel of interest P1 in step S309, thereby determining the color material amount C2 for the pixel of interest P1 so that it is equal to or less than the color material total amount limit value TH. Specifically, the total amount limiting unit 123 subtracts a predetermined color material amount from the color material amount C1 determined from the color value indicated by the color information 115 for the pixel of interest P1, to determine the color material amount C2 so that it is equal to or less than the color material total amount limit value TH.

[0037] For example, when the output color channel is composed of C (Cyan), M (Magenta), Y (Yellow), and K (Key Plate=black), the image 113 is formed on the recording medium using color materials of four colors, C, M, Y, and K. In this case, for example, color materials having a density of C=M=Y=K=100% are adhered to the recording medium in an overlapping manner, so that the recording medium is colored black. In other words, color materials having a total density of 400% of the four colors, C, M, Y, and K, are adhered to the recording medium in an overlapping manner, so that the recording medium is colored black. However, when color materials having a total density of 400% of C, M, Y, and K are adhered to a relatively wide area of ​​the recording medium, an excessive amount of color materials are adhered to the area, so that the recording medium to which the color materials are adhered may adhere to a roller that conveys the recording medium, resulting in poor fixing and winding.

[0038] Therefore, in order to prevent poor fixing and winding due to the recording medium adhering to the roller, it is assumed that a color material total amount restriction value TH of 250% is registered in the color material total amount management information 114 in association with the type of recording medium. In this case, the total amount restriction unit 123 applies the color material total amount restriction to the pixel of interest P1, thereby determining the color material amount C2 having a density of C=M=Y=K=62.5% instead of the color material amount having a density of C=M=Y=K=100%. Then, the image forming unit 104 adheres the color material of the color material amount C2 having a density of C=M=Y=K=62.5% to the position of the pixel of interest P1 on the recording medium. In this way, the image forming apparatus 100 can color the recording medium black while avoiding excessive adhesion of color material to the position of the pixel of interest P1.

[0039] In step S310, the color information acquisition unit 121 determines whether or not all pixels indicated by the image information 111 have been selected as the pixel of interest P1. If all pixels indicated by the image information 111 have not been selected as the pixel of interest P1 in step S310, the color information acquisition unit 121 selects a new pixel of interest P1 from the multiple pixels indicated by the image information 111 in step S311. Then, the control unit 107 returns the process to step S305.

[0040] On the other hand, if all pixels indicated by the image information 111 are selected as the pixel of interest P1 in step S310, the image forming unit 104 forms an image 113 based on the image information 111 on a recording medium in step S312. Specifically, the image forming unit 104 forms the image 113 such that a color material having an amount of color material C1 determined in step S307 or an amount of color material C3 determined in step S309 is attached to the recording medium at the position of each pixel indicated by the image information 111. That is, the image forming unit 104 forms an image 133 on the recording medium by attaching a color material to the recording medium based on the determination result by the determination unit 122. Then, the image output unit 105 outputs the recording medium on which the image 113 has been formed.

[0041] 4 is a diagram showing an example of a pixel region to which the total color material amount restriction is applied. An image 401 shows an image made up of a plurality of pixels represented by the image information 111.

[0042] For example, it is necessary to apply coloring material to the positions of each pixel in a region of interest 402 included in an image 401. On the other hand, in a region of interest 403 included in an image 401, pixels to which coloring material is to be applied and pixels to which coloring material is not to be applied are mixed. Therefore, the first representative value V1 calculated for the region of interest 402 is larger than the first representative value V1 calculated for the region of interest 403.

[0043] For example, it is assumed that the first representative value V1 calculated for the region of interest 402 is greater than the color material total amount restriction value TH. In this case, the total amount restriction unit 123 applies the color material total amount restriction to the pixel of interest P1 included in the region of interest 402.

[0044] On the other hand, it is assumed that the first representative value V1 calculated for the region of interest 403 is equal to or less than the color material total amount restriction value TH. In this case, the total amount restriction unit 123 does not apply the color material total amount restriction to the pixel of interest P1 included in the region of interest 403.

[0045] Moreover, the target region 404 includes a registration mark, that is, a printer's mark. Here, since the region to which the coloring material is applied for the printer's mark is relatively narrow, the target region 404 includes a mixture of pixels to which the coloring material is applied and pixels to which the coloring material is not applied. Here, it is assumed that the first representative value V1 calculated for the target region 404 is equal to or less than the coloring material total amount restriction value TH. In this case, the total amount restriction unit 123 does not apply the coloring material total amount restriction to the target pixel P1 included in the target region 404.

[0046] For example, the image forming apparatus 100 does not apply the total amount of color material restriction when applying color material to a relatively small area such as a registration mark such as a dragonfly or a star mark, etc. This allows the image forming apparatus 100 to prevent the area from becoming unclear on the recording medium on which the image 113 is formed.

[0047] Image 405 is an image formed on a recording medium by total amount restriction unit 123 determining whether or not to apply total amount restriction of color material to each pixel shown in image 401. For example, total amount restriction of color material is applied to pixels located inside area 406 included in image 405. On the other hand, total amount restriction of color material is not applied to pixels located at the boundary of area 406. This allows image forming apparatus 100 to prevent the boundary of area 406 from becoming unclear.

[0048] Similarly, the color material total amount restriction is not applied to the printer's marks, which are registration marks, shown at the four corners of the image 405. This allows the image forming apparatus 100 to prevent the printer's marks shown at the four corners of the image 405 from becoming unclear.

[0049] As a result, the image forming apparatus 100 can apply an appropriate amount of colorant to the recording medium and prevent the image from becoming unclear.

[0050] Second Embodiment The second embodiment will be described with reference to Figures 5 and 6. In the drawings, the same or similar elements are given the same reference numerals, and duplicated explanations are omitted. Configurations and processes having substantially the same functions as the other embodiments are referred to by the same reference numerals, and explanations are omitted, and differences from the other embodiments are described.

[0051] The configuration of an image forming apparatus 100 according to this embodiment is as shown in FIG.

[0052] The determination unit 122 according to the present embodiment determines that the total color material amount restriction is to be applied to each pixel of the object including the pixel of interest P1 when the first representative value V1 is greater than the total color material amount restriction value TH. On the other hand, the determination unit 122 according to the present embodiment determines that the total color material amount restriction is not to be applied to each pixel of the object including the pixel of interest P1 when the first representative value V1 is equal to or less than the total color material amount restriction value.

[0053] When the total amount control unit 123 in this embodiment determines that a color material total amount control should be applied to each pixel of an object including the target pixel P1, it sets a color material total amount control based on a color material total amount control value TH and applies a color material total amount control to each pixel of the object.

[0054] Fig. 5 is a flowchart showing an example of the operation of the image forming apparatus 100 according to this embodiment. The processes in steps S501 to S506 are similar to those in steps S301 to S306 shown in Fig. 3, and therefore detailed description thereof will be omitted.

[0055] In step S507, the determination unit 122 determines whether the first representative value V1 is greater than the color material total amount regulation value TH. If the first representative value V1 is equal to or less than the color material total amount regulation value TH in step S507, the control unit 107 moves the process to step S510.

[0056] On the other hand, if the first representative value V1 is greater than the color material total amount limit value TH in step S507, the determination unit 122 in step S508 identifies an object that includes the pixel of interest P1 and includes a pixel whose first representative value V1 is greater than the color material total amount limit value TH.

[0057] In step S509, the total amount restriction unit 123 applies a color material total amount restriction to each pixel in the specified object.

[0058] In step S510, the color information acquisition unit 121 determines whether or not all pixels to which the total color material amount restriction is not applied have been selected as the pixel of interest P1 among all pixels represented by the image information 111. If all pixels to which the total color material amount restriction is not applied have not been selected as the pixel of interest P1 among all pixels represented by the image information 111 in step S510, the color information acquisition unit 121 selects a new pixel of interest P1 from the multiple pixels represented by the image information 111 in step S511. Note that if an object is specified in step S508, the new pixel of interest P1 that is selected is a pixel different from the pixels in the specified object. Then, the control unit 107 returns the process to step S505.

[0059] On the other hand, if all pixels to which the total color material amount restriction is not applied are selected as the pixel of interest P1 among all pixels represented by the image information 111 in step S510, then in step S512 the image forming unit 104 forms an image 113 based on the image information 111 on a recording medium, and the image output unit 105 outputs the recording medium on which the image 113 has been formed. The process of step S512 is similar to the process of step S312 exemplified in FIG. 3, and therefore a detailed description thereof will be omitted.

[0060] FIG. 6 shows an example of an object 601 included in an image output when the total color material amount restriction is not applied, an example of an object 602 included in an image 113 output by the image forming apparatus 100 according to the first embodiment, and an example of an object 603 included in the image 113 output by the image forming apparatus 100 according to the present embodiment.

[0061] For example, when the total amount restriction unit 123 according to the first embodiment applies color material total amount restriction to an object 601, there will be a mixture of parts to which color material is attached due to the application of the total amount restriction and parts to which color material is attached without the application of the total amount restriction, as exemplified by an object 602. As a result, as exemplified by the object 602, even if the color value indicated by the color information 115 is uniform, the saturation and brightness will be non-uniform within the object included in the image 113.

[0062] On the other hand, when the total amount restriction unit 123 according to the present embodiment applies the color material total amount restriction to the object 601, the total amount restriction is applied to the entire object 603, as exemplified by the object 603. As a result, the image forming apparatus 100 according to the present embodiment can color the recording medium so that the saturation and brightness are uniform when the color value indicated by the color information 115 is uniform within the object included in the image 113.

[0063] As described above, the image forming apparatus 100 according to this embodiment determines whether or not to apply the total color material amount restriction for each object composed of a plurality of pixels indicated by the image information 111. As a result, the image forming apparatus 100 according to this embodiment can apply an appropriate amount of color material to the recording medium and prevent blurring, and can also avoid unevenness in the amount of color material applied to objects filled with the same color.

[0064] Third embodiment A third embodiment will be described. In the drawings, the same or similar elements are denoted by the same reference numerals, and duplicated explanations will be omitted. Configurations and processes having substantially the same functions as those of the other embodiments will be denoted by the same reference numerals, and explanations will be omitted. Differences from the other embodiments will be described.

[0065] The configuration of an image forming apparatus 100 according to this embodiment is as shown in FIG.

[0066] For example, when the pixel value of each pixel indicates the R value, G value, and B value in the RGB (Red, Green, Blue) color space, the R value, G value, and B value indicated by the image information 111 do not indicate the amount of color material. Alternatively, when the image information 111 indicates the color name of a spot color defined by a color sample, the color name indicated by the image information 111 does not indicate the amount of color material.

[0067] Therefore, for example, when the output color channels are C, M, Y, and K, the storage unit 106 according to the present embodiment stores information for converting values ​​represented by the RGB color space into values ​​represented by the CMYK color space. For example, the information for converting values ​​represented by the RGB color space into values ​​represented by the CMYK color space indicates a conversion table for converting R values, G values, and B values ​​into C values, M values, Y values, and K values. Alternatively, the storage unit 106 according to the present embodiment may store information for converting the color name of a spot color defined by a color sample into C values, M values, Y values, and K values.

[0068] Note that the image information 111 may represent image data to which halftone processing is applied. When halftone processing is applied to the image data, the value represented by the CMYK color space for each pixel represented by the image data is represented by a binary value.

[0069] The amount of color material for the same pixel differs between the image data represented by the image information 111 when halftone processing is applied and when halftone processing is not applied. Furthermore, in image data to which halftone processing is applied, the total density of color materials may locally exceed the total color material amount restriction value TH due to local overlapping of multiple color materials with relatively high density. As a result, in image data to which halftone processing is applied, image degradation may occur due to the application of total amount restriction to areas where the total density of color materials exceeds the total color material amount restriction value TH.

[0070] Therefore, the color material total amount limit value TH for image data to which halftone processing is applied may be set higher than the color material total amount limit value TH for image data to which halftone processing is not applied. This allows the image forming apparatus 100 to prevent excessive application of color material total amount restrictions when the image information 111 indicates image data to which halftone processing is applied.

[0071] Fourth embodiment The fourth embodiment will be described with reference to Figures 7 to 9. In the drawings, the same or similar elements are denoted by the same reference numerals, and duplicated explanations will be omitted. Configurations and processes having substantially the same functions as the other embodiments will be denoted by the same reference numerals, and explanations will be omitted, and differences from the other embodiments will be described.

[0072] Fig. 7 is a block diagram showing an example of the configuration of the image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 shown in Fig. 7 is different from the image forming apparatus 100 shown in Fig. 1 in that the image forming apparatus 100 shown in Fig. 7 includes an adhesion amount conversion unit 701 and stores adhesion amount conversion information 702 in the storage unit 106.

[0073] The adhesion amount conversion information 702 indicates the relationship between the color information value indicating the color value of the output color channel and the adhesion amount of the color material.

[0074] In the image forming apparatus 100 according to this embodiment, color information 115 acquired for the pixel of interest P1 and at least one reference pixel P2 indicates color values ​​converted into output color channels for the pixel of interest P1 and at least one reference pixel P2.

[0075] The adhesion amount converter 701 converts the color information 115 acquired for the pixel of interest P1 and at least one reference pixel P2 into an adhesion amount 703 of color material to be adhered to the recording medium for the pixel of interest P1 and at least one reference pixel P2.

[0076] The determination unit 122 according to this embodiment determines whether or not to apply the color material total amount restriction to the pixel of interest P1 based on the adhesion amount 703 converted for the pixel of interest P1 and at least one reference pixel P2. Specifically, when a second representative value V2 of the adhesion amount 703 converted for the pixel of interest P1 and at least one reference pixel P2 is greater than the total color material amount restriction value TH, the determination unit 122 determines to apply the color material total amount restriction to the pixel of interest P1. On the other hand, when the second representative value V2 is equal to or less than the total color material amount restriction value TH, the determination unit 122 determines not to apply the color material total amount restriction to the pixel of interest P1. For example, the second representative value V2 is an average value of the adhesion amount 703 for the pixel of interest P1 and at least one reference pixel P2.

[0077] FIG. 8A is a graph showing an example of the relationship between the color difference from the paper white, the adhesion amount, and the color information value of the output color channel. In the graph 801 shown in FIG. 8A, the horizontal axis represents the color difference from the paper white, and the vertical axis represents the color information value of the output color channel. In the graph 802 shown in FIG. 8A, the horizontal axis represents the color difference from the paper white, and the vertical axis represents the adhesion amount. The color information value of the output color channel shown in FIG. 8A indicates one of the C value, M value, Y value, and K value. Therefore, the color difference from the paper white shown in FIG. 8A indicates the color of the object surface determined from the perceived lightness and saturation for the color of the value indicated by the color information value of the output color channel. Similarly, the adhesion amount shown in FIG. 8A indicates the adhesion amount of the color material for the color of the value indicated by the color information value of the output color channel.

[0078] As shown in graph 802, there is a linear relationship between the color difference from the paper white and the color information value of the output color channel, and as the color difference from the paper white increases, the color information value of the output color channel increases linearly. On the other hand, as shown in graph 802, there is a non-linear relationship between the color difference from the paper white and the adhesion amount. Here, the perceived lightness and chroma do not exceed the maximum lightness and maximum chroma of the colorant. Therefore, as shown in FIG. 8A, when the adhesion amount increases, the perceived lightness and chroma converge to a color difference E determined from the maximum lightness and maximum chroma of the colorant.

[0079] Fig. 8B is a graph showing an example of the relationship between the color information value indicating the color value of the output color channel and the adhesion amount. In Fig. 8B, the horizontal axis represents the color information value indicating the color value of the output color channel, and the vertical axis represents the adhesion amount. As shown in Fig. 8B, the lightness and saturation calculated from the maximum color information value of the output color channel do not exceed the maximum lightness and maximum saturation of the colorant. Therefore, as shown in Fig. 8B, when the adhesion amount increases, the color information value of the output color channel converges to a predetermined maximum value L.

[0080] 9 is a flowchart showing an example of the operation of the image forming apparatus 100 according to the present embodiment. The processes from step S901 to step S905 are similar to the processes from step S301 to step S305 shown in FIG.

[0081] In step S906, the adhesion amount conversion unit 701 converts the color information 115 for each pixel in the region of interest R into an adhesion amount 703. Specifically, the adhesion amount conversion unit 701 converts the color value indicated by the color information 115 for each pixel in the region of interest R into the color value of the output color channel. Then, the adhesion amount conversion unit 701 determines the adhesion amount 703 for each pixel in the region of interest R from the relationship between the color value of the output color channel and the adhesion amount indicated by the adhesion amount conversion information 702.

[0082] In step S907, the determination unit 122 calculates a second representative value V2 of the adhesion amount 703 for the region of interest R. For example, the second representative value V2 is the average value of the adhesion amount 703 for each pixel in the region of interest R.

[0083] In step S908, the determination unit 122 determines whether the second representative value V2 is greater than the color material total amount restriction value TH. If the second representative value V2 is equal to or less than the color material total amount restriction value TH in step S908, the total amount restriction unit 123 does not apply the color material total amount restriction to the pixel of interest P1 in step S909. Then, the control unit 107 proceeds to step S911.

[0084] On the other hand, if the second representative value V2 is greater than the color material total amount restriction value TH in step S908, the total amount restriction unit 123 applies color material total amount restriction to the pixel of interest P1 in step S910. The process of step S910 is similar to step S309 illustrated in FIG. 3, and will be described in detail. Then, the control unit 107 proceeds to step S911. The process from step S911 onwards is similar to the process from S310 onwards illustrated in FIG. 3, and will not be described in detail.

[0085] As described above, the image forming apparatus 100 according to this embodiment determines whether or not to apply the total color material amount restriction to the pixel of interest P1 based on the amount of color material substantially required for each pixel in the region of interest R. This allows the image forming apparatus 100 according to this embodiment to apply the total color material amount restriction more effectively.

[0086] Fifth embodiment The fifth embodiment will be described with reference to Figures 10A and 10B. In the drawings, the same or similar elements are denoted by the same reference numerals, and duplicated descriptions will be omitted. Configurations and processes having substantially the same functions as the other embodiments will be denoted by the same reference numerals, and descriptions will be omitted, and differences from the other embodiments will be described.

[0087] The configuration of an image forming apparatus 100 according to this embodiment is as shown in FIG.

[0088] The determination unit 122 according to this embodiment determines that the total color material amount restriction is to be applied to each pixel of the object including the pixel of interest P1 when the second representative value V2 is greater than the total color material amount restriction value TH. On the other hand, the determination unit 122 determines that the total color material amount restriction is not to be applied to each pixel of the object including the pixel of interest P1 when the second representative value V2 is equal to or less than the total color material amount restriction value TH.

[0089] When the total amount control unit 123 in this embodiment determines that a total amount control of color material should be applied to each pixel of an object including the target pixel P1, it sets a total amount control of color material based on a total amount control value and applies the total amount control of color material to each pixel of the object.

[0090] 10A and 10B are flowcharts showing an example of the operation of image forming apparatus 100 according to the present embodiment. The processes of steps S1001 to S1005 shown in FIG. 10A are similar to the processes of steps S301 to S305 shown in FIG. 3, and therefore detailed descriptions thereof will be omitted. Also, the processes of steps S1006 and S1007 shown in FIG. 10A and step S1008 shown in FIG. 10B are similar to the processes of steps S906 to S908 shown in FIG. 9, and therefore detailed descriptions thereof will be omitted.

[0091] In step S1008, the determination unit 122 determines whether the second representative value V2 of the adhesion amount 703 is greater than the color material total amount limit value TH. If the second representative value V2 is equal to or less than the color material total amount limit value TH in step S1008, the control unit 107 transitions to step S1011.

[0092] On the other hand, if the second representative value V2 is greater than the color material total amount limit value TH in step S1008, the determination unit 122 in step S1009 identifies an object that includes the pixel of interest P1 and includes a pixel whose second representative value V2 is greater than the color material total amount limit value TH.

[0093] In step S1010, the total amount restriction unit 123 applies a color material total amount restriction to each pixel in the identified object.

[0094] In step S1011, the color information acquisition unit 121 determines whether or not all pixels to which the total color material amount restriction is not applied have been selected as pixels of interest among all pixels represented by the image information 111. If all pixels to which the total color material amount restriction is not applied have not been selected as pixels of interest among all pixels represented by the image information 111 in step S1011, the color information acquisition unit 121 selects a new pixel of interest P1 from the multiple pixels represented by the image information 111 in step S1012. Note that if an object is specified in step S1009, the new pixel of interest P1 to be selected is a pixel different from the pixel in the specified object. Then, the control unit 107 returns the process to step S1005 illustrated in FIG. 10A.

[0095] On the other hand, if all pixels to which the total color material amount restriction is not applied are selected as pixels of interest among all pixels indicated by image information 111 in step S1011, then in step S1013 image forming unit 104 forms image 113 based on image information 111 on a recording medium, and image output unit 105 outputs the recording medium on which image 113 has been formed. The process of step S1013 is similar to the process of step S312 exemplified in FIG. 3, and therefore a detailed description thereof will be omitted.

[0096] As described above, the image forming apparatus 100 according to this embodiment can achieve the same effects as the image forming apparatus 100 according to the second embodiment, and can also achieve the same effects as the image forming apparatus 100 according to the fourth embodiment.

[0097] Sixth embodiment The sixth embodiment will be described with reference to Figures 11A and 11B. In the drawings, the same or similar elements are denoted by the same reference numerals, and duplicated descriptions will be omitted. Configurations and processes having substantially the same functions as the other embodiments will be denoted by the same reference numerals, and descriptions will be omitted, and differences from the other embodiments will be described.

[0098] Fig. 11A is a diagram showing an example of an area 1102 where a coloring material is adhered to a recording medium 1101. Fig. 11B is a diagram showing an example of an area 1103 where a coloring material is adhered to a recording medium 1101.

[0099] The image forming apparatus 100 includes a roller 1104, which is a conveying unit, arranged so that an area in contact with the recording medium is perpendicular to a first direction, which is a conveying direction of the recording medium. The area 1102 has a length shorter in a second direction perpendicular to the first direction than the first direction in which the recording medium is conveyed. When coloring material adheres to the area 1102 of the recording medium 1101, the coloring material adheres to a part of the roller 1104 along the second direction. As exemplified by the area 1102, even if an area with a relatively large amount of coloring material adhered has a length extending in the first direction, if the length along the second direction is relatively short, poor fixing and wrapping due to the recording medium 1101 adhering to the roller 1104 are unlikely to occur.

[0100] On the other hand, the region 1103 has a length that covers the entire roller 1104 along the second direction. When the coloring material adheres to the region 1103 in the recording medium 1101, the coloring material adheres to the entire roller 1104 along the second direction. As exemplified in the region 1103, even if a region with a relatively large amount of adhered coloring material has a length extending in the first direction, if the length along the second direction is relatively short, poor fixing and winding due to the recording medium 1101 adhering to the roller 1104 are likely to occur. Therefore, when the coloring material adheres to the region 1103 in the recording medium 1101, there is a risk that poor fixing and winding will occur due to the coloring material adhering more to the roller 1104 than when the coloring material adheres to the region 1102 in the recording medium 1101.

[0101] Here, the region of interest R according to this embodiment is rectangular, and has a length in the second direction longer than the length in the first direction on the recording medium on which the image 113 is formed. This allows the determination unit 122 to determine whether or not an excessive amount of coloring material may adhere to the roller 1104. If an excessive amount of coloring material may adhere to the recording medium 1101, the total amount restriction unit 123 applies a total amount restriction on the coloring material, so that the image forming apparatus 100 can prevent poor fixing and wrapping caused by the recording medium 1101 adhering to the roller 1104.

[0102] In addition, when an excessive amount of coloring material adheres to the end of the recording medium 1101 on the first direction side, poor fixing and winding are likely to occur due to the end of the recording medium 1101 adhering to the roller 1104 starting from the end of the recording medium 1101. Therefore, the area of ​​the attention area R, which is a position on the first direction side of the recording medium 1101, may be larger than the area of ​​the attention area R, which is a position on the opposite side of the first direction of the recording medium 1101. This allows the determination unit 122 to more appropriately determine whether or not the amount of coloring material adhered to the end of the recording medium 1101 on the first direction side is relatively large. As a result, when an excessive amount of coloring material may adhere to the end of the recording medium 1101 on the first direction side, the total amount control unit 123 can more effectively prevent poor fixing and winding caused by the end of the recording medium 1101 adhering to the roller 1104.

[0103] Seventh embodiment The seventh embodiment will be described with reference to Figures 12A and 12B. In the drawings, the same or similar elements are given the same reference numerals, and duplicated explanations will be omitted. Configurations and processes having substantially the same functions as the other embodiments will be referred to by the same reference numerals, and explanations will be omitted, and differences from the other embodiments will be described.

[0104] Fig. 12A is a diagram showing an example of the relationship between a pixel of interest P1 and a reference pixel P2 in the image forming apparatus 100 according to this embodiment. As shown in Fig. 12A, in the image forming apparatus 100 according to this embodiment, on a recording medium on which an image 113 is formed, the position of at least one reference pixel P2 is not aligned along the second direction or the first direction with respect to the position of the pixel of interest P1.

[0105] FIG. 12B is a diagram showing an example of a recording medium 1201 on which registration marks for managing printed products are printed. The image forming apparatus 100 includes a roller 1202, which is a conveying unit arranged so that an area in contact with the recording medium is perpendicular to a first direction, which is a conveying direction of the recording medium. A registration mark for managing printed products is printed in an area 1203 included in the recording medium 1201. When coloring material adheres to a thin line portion such as the registration mark included in the area 1203, poor fixing and winding due to adhesion of the recording medium 1201 to the roller 1202 are unlikely to occur. However, when the total amount restriction unit 123 determines that the total amount restriction of the coloring material amount should be applied to a thin line such as the registration mark included in the area 1203, the coloring material may not be sufficiently attached to the thin line, resulting in blurring.

[0106] However, in the image forming apparatus 100 according to this embodiment, the position of at least one reference pixel P2 is not aligned with the second direction or the first direction relative to the position of the pixel of interest P1, so that it is possible to prevent the application of the total color material amount restriction to thin lines such as a register mark. Furthermore, when a rectangular area is referenced, a relatively large number of pixels must be referenced. On the other hand, the image forming apparatus 100 according to this embodiment only needs to reference limited pixels at predetermined positions, so the number of reference pixels is smaller than when a rectangular area is referenced. This allows the image forming apparatus 100 according to this embodiment to reduce memory capacity and increase processing speed, and efficiently determine the target of the total amount restriction.

[0107] The processes executed in the above-described embodiments are not limited to the process modes exemplified in the above-described embodiments. The above-described functional blocks may be realized using either a logic circuit (hardware) formed in an integrated circuit or the like, or software using a CPU. The above-described implementation may be executed by multiple computers. For example, the processes executed in each functional block of the control unit 107 of the image forming apparatus 100 may be partially executed by another computer, or all of the processes may be shared and executed by multiple computers.

[0108] The present disclosure is not limited to the above-mentioned embodiment, and may be replaced with a configuration substantially the same as the configuration shown in the above-mentioned embodiment, a configuration having the same action and effect, or a configuration capable of achieving the same purpose. The present disclosure also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Furthermore, by combining the technical means disclosed in each embodiment, a new technical feature can be formed. [Explanation of symbols]

[0109] 100 image forming apparatus, 101 display unit, 102 operation unit, 103 image input unit, 104 image forming unit, 105 image output unit, 106 storage unit, 107 control unit, 111 image information, 112 recording medium information, 113 image, 114 color material total amount management information, 115 color information, 121 color information acquisition unit, 122 judgment unit, 123 total amount control unit, 401 image, 402 area of ​​interest, 403 area of ​​interest, 404 area of ​​interest, 405 image, 406 area, 601 object, 602 object, 603 object, 701 adhesion amount conversion unit, 702 adhesion amount conversion information, 703 adhesion amount, 1101 recording medium, 1102 area, 1103 area, 1104 roller, 1201 recording medium, 1202 Roller, 1203 area

Claims

1. a color information acquisition unit that acquires color information indicating a color value for each pixel in a region of interest that includes a pixel of interest among a plurality of pixels that constitute an image and at least one reference pixel different from the pixel of interest among the plurality of pixels; a determination unit that determines whether or not to apply a total amount restriction of coloring material to be applied to the pixel of interest based on the color information; an image forming unit that forms the image on a recording medium by applying a coloring material to the recording medium based on a result of the determination by the determination unit; Equipped Image forming device.

2. the determination unit determines that the total color material amount restriction is to be applied to the pixel of interest when a first representative value of color values ​​indicated by color information acquired for the pixel of interest and the at least one reference pixel is greater than a total color material amount restriction value set in accordance with the recording medium, and determines that the total color material amount restriction is not to be applied to the pixel of interest when the first representative value is equal to or less than the total color material amount restriction value; a total amount restriction unit that sets the total amount restriction of color materials based on the total amount restriction value of color materials and applies the total amount restriction of color materials to the pixel of interest when it is determined that the total amount restriction of color materials is to be applied to the pixel of interest; Further equipped The image forming apparatus according to claim 1 .

3. the determination unit determines that the total color material amount restriction is to be applied to each pixel of the object including the pixel of interest when the first representative value is greater than the total color material amount restriction value, and determines that the total color material amount restriction is not to be applied to each pixel of the object when the first representative value is equal to or less than the total color material amount restriction value, When it is determined that the total color material amount restriction is to be applied to each pixel of the object, the total amount restriction unit sets the total color material amount restriction based on the total color material amount restriction value, and applies the total color material amount restriction to each pixel of the object. The image forming apparatus according to claim 2 .

4. The first representative value is an average value of color values ​​indicated by color information obtained for the pixel of interest and the at least one reference pixel.

4. The image forming apparatus according to claim 2 or 3.

5. The color information obtained for the pixel of interest and the at least one reference pixel indicates color values ​​converted into output color channels for the pixel of interest and the at least one reference pixel. The image forming apparatus according to claim 1 .

6. an adhesion amount conversion unit that converts the color information acquired for the pixel of interest and the at least one reference pixel into adhesion amounts of color material to be adhered to the recording medium for the pixel of interest and the at least one reference pixel; Further equipped with The determining unit determines whether or not to apply a total color material amount restriction to the pixel of interest based on the converted adhesion amounts for the pixel of interest and the at least one reference pixel. The image forming apparatus according to claim 1 .

7. the determination unit determines that the total color material amount restriction is to be applied to the pixel of interest when a second representative value of the adhesion amounts converted for the pixel of interest and the at least one reference pixel is greater than a total color material amount restriction value set in accordance with the recording medium, and determines that the total color material amount restriction is not to be applied to the pixel of interest when the second representative value is equal to or less than the total color material amount restriction value; a total amount restriction unit that sets the total amount restriction of color materials based on the total amount restriction value of color materials and applies the total amount restriction of color materials to the pixel of interest when it is determined that the total amount restriction of color materials is to be applied to the pixel of interest; Further equipped 7. The image forming apparatus according to claim 6.

8. the determination unit determines that the total color material amount restriction is to be applied to each pixel of the object including the pixel of interest when the second representative value is greater than the total color material amount restriction value, and determines that the total color material amount restriction is not to be applied to each pixel of the object when the second representative value is equal to or less than the total color material amount restriction value, When it is determined that the total color material amount restriction is to be applied to each pixel of the object, the total amount restriction unit sets the total color material amount restriction based on the total color material amount restriction value, and applies the total color material amount restriction to each pixel of the object. The image forming apparatus according to claim 7.

9. The second representative value is an average value of the adhesion amounts for the pixel of interest and the at least one reference pixel.

9. The image forming apparatus according to claim 7 or 8.

10. A conveying section arranged so that an area in contact with the recording medium is perpendicular to a first direction which is a conveying direction of the recording medium. Further equipped with The region of interest is rectangular, and has a length along a second direction perpendicular to the first direction that is longer than a length along the first direction on the recording medium on which the image is formed. The image forming apparatus according to claim 1 .

11. A conveying section arranged so that an area in contact with the recording medium is perpendicular to a first direction which is a conveying direction of the recording medium. Further equipped with On the recording medium on which the image is formed, the position of the at least one reference pixel is in a position that is not aligned with the first direction and in a second direction perpendicular to the first direction with respect to the position of the target pixel. The image forming apparatus according to claim 1 .

12. a color information acquiring step of acquiring color information indicating a color value for each pixel in a region of interest that includes a pixel of interest among a plurality of pixels that constitute an image and at least one reference pixel that is different from the pixel of interest among the plurality of pixels; a determining step of determining whether or not to apply a total amount restriction of coloring material to be applied to the pixel of interest based on the color information; an image forming step of forming the image on the recording medium by applying a coloring material to the recording medium based on the result of the determination step; Includes Image forming method.

13. On the computer, a color information acquisition function that acquires color information indicating a color value for each pixel in a region of interest that includes a pixel of interest among a plurality of pixels that constitute an image and at least one reference pixel that is different from the pixel of interest among the plurality of pixels; a determining function for determining whether or not to apply a total amount restriction of a color material to be applied to the pixel of interest based on the color information; an image forming function for forming the image on a recording medium by applying a coloring material to the recording medium based on a result of the determination function; Run program.

Images