JP2012245707A - Apparatus, method, and program for image processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce the consumption of color materials depending on the size of an object formed on a recording medium.SOLUTION: An image processing apparatus 16 calculates a visual angle to the object printed on the recording medium, on the basis of an intensive number and the magnification set as a printing method. In the image processing apparatus 16, the object having a visual angle smaller than limit visual angle information is determined as an object whose color material amount is to be reduced, and the object determined is subjected to color-material-amount reduction processing.

Description

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

  In an image forming apparatus that forms an image using a color material such as toner or ink, a technique for reducing the amount of color material used is known. As this technique, for example, there are aggregate printing in which image data of a plurality of pages is reduced and printed on one recording medium, reduced printing in which an image is reduced and printed, and the like.

  Further, in Patent Document 1, it is determined that color printing is possible when an aggregation number equal to or greater than a predetermined value is set, and it is determined that color printing is not possible when an aggregation number less than a predetermined value is set. It is disclosed.

  However, in Patent Document 1, color printing is also performed on objects such as characters and images that are printed in a size that makes it difficult for a person to perceive color through aggregate printing. For this reason, a plurality of kinds of color materials have been consumed for printing an object of an unperceived color.

  The present invention has been made in view of the above, and an image processing apparatus and an image that can effectively reduce the amount of color material used according to the size of an object when formed on a recording medium. It is an object to provide a processing method and an image processing program.

  In order to solve the above-described problems and achieve the object, the present invention provides a designation unit that receives printing method information including at least one of an aggregation number and a scaling factor, and a limit viewing angle that indicates a limit viewing angle at which a person can perceive color. Based on storage means that stores information in advance, image data including color data of one or more objects, and the printing method information, a viewing angle for the object when printed on a recording medium is calculated, and the calculated viewing angle is Determining means for determining an object that is equal to or less than the limit viewing angle information as a color material amount reduction target, and reducing the color material usage amount of the object determined as the color material amount reduction target among the objects in the image data The image processing apparatus further includes conversion means for converting the color data of the object in the image data.

  The present invention is also an image processing method executed by an image processing device, the image processing device comprising storage means that stores in advance limit viewing angle information indicating a limit viewing angle at which a person can perceive color, and is consolidated. A step of receiving printing method information including at least one of a number and a scaling ratio; image data including color data of one or more objects; and a viewing angle with respect to the object when printed on a recording medium based on the printing method information And determining an object whose calculated viewing angle is equal to or less than the limit viewing angle information as a color material amount reduction target, and among the objects in the image data, the color of the object determined as the color material amount reduction target Converting the color data of the object in the image data so as to reduce material usage. An image processing method.

  Further, the present invention is an image processing program to be executed by a computer, and the computer includes storage means that stores in advance limit viewing angle information indicating a limit viewing angle at which a person can perceive color, and includes an aggregation number and a variable number. Based on the step of receiving printing method information including at least one of magnifications, image data including color data of one or more objects and the printing method information, a viewing angle for the object when printed on a recording medium is calculated. Determining an object whose calculated viewing angle is equal to or less than the limit viewing angle information as a color material amount reduction target, and among the objects in the image data, the color material usage amount of the object determined as the color material amount reduction target The step of converting the color data of the object in the image data is reduced. When a image processing program for causing the computer to perform.

  According to the present invention, there is an effect that the amount of color material used can be effectively suppressed according to the size of an object when formed on a recording medium.

FIG. 1 is a block diagram illustrating the overall configuration of the image forming apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of limit viewing angle information stored in the storage unit. FIG. 2A is a diagram illustrating an example of limit viewing angle information stored in association with RGB hue information. ) Is a diagram illustrating an example of limit viewing angle information stored in association with RGB hue information and lightness information. FIG. 3 is a block diagram illustrating the overall configuration of the image forming apparatus according to the first embodiment. 4A and 4B are schematic diagrams illustrating an example of image data. FIG. 4A is a schematic diagram illustrating image data before monochrome processing, and FIG. 4B is a schematic diagram illustrating image data after monochrome processing. is there. FIG. 5 is a schematic diagram showing the calculation of the viewing angle. FIG. 6 is a sequence diagram illustrating a procedure of image processing according to the first embodiment. FIG. 7 is a schematic diagram illustrating an example of an input screen. FIG. 8 is a schematic diagram showing an example of the input screen. FIG. 9 is a schematic diagram illustrating an example of an input screen. FIG. 10 is a block diagram illustrating the overall configuration of the image forming apparatus according to the second embodiment. FIG. 11 is a schematic diagram illustrating an example of an input screen. FIG. 12 is a block diagram illustrating a hardware configuration example of the image processing apparatus according to the first embodiment and the second embodiment.

  Exemplary embodiments of an image processing apparatus and an image processing method according to the present embodiment will be described below in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating an overall configuration of an image processing apparatus according to the first embodiment and an image forming apparatus 10 using the same. The image forming apparatus 10 includes an image processing device 16 and an image forming unit 14.

  The image processing device 16 performs various image processing on the image data to be printed. The image processing device 16 includes a designation unit 12, a processing unit 18, and a storage unit 20.

  The designation unit 12 receives printing method information indicating a printing method. The printing method information includes information indicating presence / absence of aggregate printing, the number of aggregations, presence / absence of variable magnification printing, variable magnification, and presence / absence of color material amount reduction processing. In the present embodiment, a case will be described in which the printing method information includes information indicating presence / absence of aggregate printing, the number of aggregations, presence / absence of variable magnification printing, variable magnification, and presence / absence of color material amount reduction processing. However, the printing method information may be information including at least one of the aggregation number and the scaling ratio.

  The designation unit 12 receives printing method information when an operation instruction is given by the user. Examples of the designation unit 12 include known input devices such as a touch panel, a keyboard, and a mouse.

  The storage unit 20 stores in advance limit viewing angle information indicating a limit viewing angle at which a person perceives color, in association with hue information. That is, the memory | storage part 20 memorize | stores beforehand the information which shows the person's limit visual angle with respect to each hue. The limit viewing angle refers to a limit viewing angle at which a person can distinguish colors when an object such as a character is observed from a predetermined distance f. Distinguishing colors means distinguishing between achromatic colors and chromatic colors. The viewing angle is an angle formed by an object projected on the human eye. Specifically, the viewing angle indicates an angle formed by the object projected on the human eye when an object such as a character is observed from a predetermined distance f. In the present embodiment, the limit of the size with which a person can distinguish the color is defined by the viewing angle. In the present embodiment, it is assumed that the distance f used when determining the limit viewing angle is the same as the distance f used when determining the viewing angle. As the distance f, the storage unit 20 stores in advance the distance between the recording medium and the human eye when the person visually recognizes the object printed on the recording medium. Examples of the distance f include 50 cm, but are not limited thereto.

  Here, human vision will be briefly described. On the retina of the human eye, there are three types of cells called cones (L cone, M cone, S cone) and cells called rods. The cones have the property of feeling light stimuli of red, green and blue, respectively. The body has the property of feeling brightness. Humans perceive color by light stimulation incident on each cone cell. The number of rods and cones is about 100 million and 7 million, respectively, and the ratio of the number of the above three types of cone cells is generally 32 to 16 to 1, although there are individual differences. Yes. Cones are overwhelmingly smaller in number than cones, and it is difficult to perceive color unless sufficiently strong light is incident. In addition, among the cones, the number of S cones is particularly small. For this reason, human sensitivity to blue light is low. Therefore, for example, when there is a very small character, it becomes difficult for a human to feel the color in the order of blue> green> red. That is, the human limit viewing angle for objects such as blue (B) characters is larger than the human limit viewing angle for green (G) and red (R) objects (see FIG. 2A). Details of the object will be described later.

  For this reason, the memory | storage part 20 is shown to FIG. 2 (A) as limit visual angle information corresponding to each of R (red), G (green), and B (blue) which is the information which shows each hue, for example. Store information. In FIG. 2, the limit viewing angle information is indicated by the unit 'min'. 1 min corresponds to 1/60 degrees.

  Note that the limit viewing angle information shown in FIG. 2 (A) is a statistical analysis of the limit viewing angle in which a plurality of types of black characters and color characters having different sizes are prepared and visually recognized by a plurality of people, and the difference in color is hardly understood. It is an obtained example. That is, the limit viewing angle information illustrated in FIG. 2A is an example, and the limit viewing angle information stored in the storage unit 20 is not limited to the value illustrated in FIG.

  Further, in the present embodiment, the storage unit 20 describes the case of storing the limit viewing angle information in association with the hue information, but may further store the brightness information in association with it.

  For example, even if the hue is the same, if the lightness is different, the limit viewing angle is different. For this reason, for example, as shown in FIG. 2B, the storage unit 20 stores the limit viewing angle information in association with information indicating the hue and brightness (high brightness and low brightness in FIG. 2B). May be.

  Returning to FIG. 1, the processing unit 18 receives image data to be printed. This image data includes information indicating a drawing command for one or more objects. An object is a drawing target indicated by the same color and size, and examples thereof include characters, tables, straight lines, and figures. This drawing command includes information indicating the printing position of each object, information indicating the size of the object, and color data indicating the color of the object.

  Note that the processing unit 18 may receive image data from a storage unit (not shown), or may receive image data from an external device such as a personal computer via a wireless or wired communication line (not shown). . When the image forming apparatus 10 includes a known scanner device, the processing unit 18 may accept image data read by the scanner device.

  As shown in FIG. 3, the processing unit 18 includes a determination unit 18A and a conversion unit 18B. Based on the image data, the printing method information, and the limit viewing angle information, the determination unit 18A determines whether or not each of one or more objects included in the image data is a color material amount reduction target object ( Details will be described later). The conversion unit 18B changes the color data of the object so as to reduce the color material usage amount of the object determined as the color material amount reduction target by the determination unit 18A.

  Specifically, the determination unit 18A prints each object in the image data on a recording medium from information indicating the size of each object indicated in the image data and the aggregation number and scaling factor included in the printing method information. The size of each object (that is, the size on the recording medium) is calculated. Then, the determination unit 18A calculates the viewing angle for each object of the size from the size of each object at the time of printing.

  The determination unit 18A calculates the viewing angle as follows.

  FIG. 4A shows an example of image data described in a page description language. The determination unit 18A first searches the image data for a place where information indicating the size of each object is described. Specifically, when the image data is the image data shown in FIG. 4A, the determination unit 18A receives a command such as FontSize, RectFill, LineWidth, and the like indicating the designation of character size, drawing, and line width. Search the described part.

  Next, the determination unit 18A calculates the viewing angle for each object when the corresponding object is printed on the recording medium with the information indicating the size.

  Specifically, first, the determination unit 18A calculates information indicating the size at the time of printing in a case where collective printing or scaling printing is not performed, from information indicating the size of each object in the image data.

  For example, the determination unit 18A uses reference information and a conversion table for calculating information indicating the size at the time of printing when aggregate printing or scaling printing is not performed from information indicating the size of each object in the image data. And conversion formulas are stored in advance. Then, the determination unit 18A calculates information indicating the size of each object at the time of printing when aggregate printing or scaling printing is not performed, from information indicating the size of each object indicated in the image data.

  For example, in C101 of FIG. 4A, 10 points are designated as the character size. Usually, a character size of 10 points corresponds to a character height of about 2.25 mm when printed on a recording medium. Generally, when not performing collective printing or reduced printing, size information such as the number of character points designated by word processing software and size information such as character size on a recording medium are uniquely determined. For this reason, in the present embodiment, the determination unit 18A holds reference information serving as a reference in advance, and in comparison with the reference information, the size at the time of printing of each object when aggregate printing or reduced printing is not performed. Is calculated.

  For example, the determination unit 18A associates the information indicating 20 points as the size information specified in the image data with the size 4 on the recording medium at the time of printing when the collective printing or the reduced printing is not performed. . Information indicating .5 mm is stored. Then, when 10 points are specified as the size information of the object in the image data, the determination unit 18A uses the following formula (A) to calculate 2.25 mm that is the size when the object is printed. calculate.

  4.5 × (10/20) = 2.25 mm Formula (A)

  Next, the determination unit 18A performs aggregate printing and scaling printing using the aggregation number and scaling ratio included in the printing method information from information indicating the size of each object when printing is not performed. Information indicating the size of the recording medium when it is performed is calculated.

  For example, it is assumed that the printing method information includes information indicating the aggregation number “2” and the scaling factor “80%”. Assume that a certain object has a size of 2.25 mm on the recording medium when the collective printing and the variable magnification printing are not performed. In this case, the determination unit 18A uses the following equation (B), and is 0, which is the size when the object is printed when aggregate printing and scaling printing are performed with the aggregation number and scaling ratio included in the printing method information. Calculate 09 cm.

  2.25 × (1/2) × 0.8 = 0.9 mm = 0.09 cm Formula (B)

  Then, the determination unit 18A performs the same calculation for all objects included in the image data.

  Next, the determination unit 18A obtains information indicating the size of each object on the recording medium when printing is performed with aggregate printing and scaling printing at the aggregation number and scaling ratio included in the printing method information. Convert to viewing angle.

  For example, assume that the object P shown in FIG. 5 is formed on the recording medium. In this case, the determination unit 18A calculates θ from the following formulas (1) and (2). Then, the viewing angle 2θ with respect to the object P is obtained by doubling the calculated θ.

tan θ = d / f (1)
θ = tan ⁻¹ (d / f) (2)

  In Expressions (1) and (2), d indicates a value that is ½ of the length of the object P (see the distance d between AMs in FIG. 5). In Expressions (1) and (2), f indicates an observation distance (the shortest distance between the eyes and the object) (see the distance f between OMs in FIG. 5). In the expressions (1) and (2), θ represents a value that is ½ of the viewing angle (2θ).

  In the formulas (1) and (2), θ is a radian unit. For this reason, the determination unit 18A multiplies the value of 2θ by 180 / π to convert the value to a degree used for the visual angle notation.

  For example, the viewing angle 2θ is calculated for the above-mentioned object in which the size at the time of printing of the object is 0.09 cm when aggregate printing and scaling printing are performed at the aggregation number and scaling ratio included in the printing method information calculated above. When determining, the determination unit 18A calculates the viewing angle 2θ by the following equation (C).

  2θ = arctan (0.09 / 2/50) * 180 / π * 2≈0.1 deg. ≒ 6.2min Formula (C)

  Next, the determination unit 18A determines an object whose viewing angle with respect to each object when formed on the recording medium is less than the limit viewing angle information corresponding to the hue of each object as a color material amount reduction target. Then, the determination unit 18A sends the image data and the determination results of all the objects included in the image data to the conversion unit 18B.

  Specifically, the determination unit 18A first determines the hue of the object from the color data of the object to be determined included in the image data. It is assumed that the storage unit 20 stores the limit viewing angle information corresponding to each position on the hue circle of the hue. In this case, the determination unit 18A reads the limit viewing angle information corresponding to the determined hue from the storage unit 20. Then, the determination unit 18A determines the object as a color material amount reduction target when the viewing angle information when the object is formed on the recording medium is less than the read limit viewing angle information.

  It is assumed that the storage unit 20 stores limit viewing angle information corresponding to each of the three primary colors (R (red), G (green), and B (blue)) of light in the hue. In this case, the determination unit 18A determines from the color data of each object whether the hue is closest to red, green, or blue, and can read the limit viewing angle information corresponding to the determined hue from the storage unit 20. That's fine.

  Further, it is assumed that the storage unit 20 stores the limit viewing angle information in association with both the hue and the brightness. In this case, the determination unit 18A may determine the hue and brightness of each object from the color data of each object, and read the limit viewing angle information corresponding to the determined hue and brightness from the storage unit 20.

  Specifically, it is assumed that the image data is the image data shown in FIG. In this case, the determination unit 18 </ b> A reads “113, 88, 143”, which is specified by the RGB value as FontColor in C102 as the color data of a certain object. Then, from this value, the determination unit 18A determines the hue of the object. For example, the determination unit 18A determines B (blue) having the largest gradation value as the hue of the object as a simple process. As described above, the determination unit 18A may convert the RGB value into an HSL or HSV color space using a unique conversion formula, and determine the hue (or lightness) of the object based on the hue angle or lightness. .

  Then, the determination unit 18A reads the limit viewing angle information corresponding to the hue of each object from the storage unit 20, and when the viewing angle information when the object is formed on the recording medium is less than the read limit viewing angle information, The object is determined as a color material amount reduction target.

  Specifically, it is assumed that the limit viewing angle information shown in FIG. In this case, the determination unit 18A reads 15.1 min that is the limit viewing angle information corresponding to the blue hue (B). In this case, the determination unit 18A determines the object as a color material amount reduction target because the viewing angle 6.2 min with respect to the object is less than the limit viewing angle information 15.1 min.

  In the image data shown in FIG. 4A, an instruction to fill a rectangular area is described in C302 as a certain object with the coordinates of the start point and the number of points in the vertical and horizontal directions. The size of this object shown in the image data is 15 points in each direction. When calculated in the same manner as described above, the viewing angle of this object is 23.3 min. For this reason, the determination unit 18A determines that this object is not subject to color material amount reduction.

  Then, when the determination unit 18A performs the above process on all the objects included in the image data received by the processing unit 18, the determination unit 18A sends the image data received by the processing unit 18 and the determination result to the conversion unit 18B. . As a determination result, the determination unit 18A sends object identification information in the image data and reduction target information or non-reduction target information corresponding to each object to the conversion unit 18B.

  Returning to FIG. 3, the conversion unit 18 </ b> B uses the color material only for the object determined as the color material amount reduction target among the objects in the image data based on the image data received from the determination unit 18 </ b> A and the determination result. The color data of the object is changed so as to reduce the amount.

  In the present embodiment, as the color material usage amount reduction process, the conversion unit 18B converts the color of the color data of the object determined as the color material amount reduction target into a monochrome (achromatic color). For example, the conversion unit 18B changes the color data of the object so that the hue of the object determined as the color material amount reduction target is monochrome.

  For example, assume that the image data is the image data shown in FIG. In this case, the conversion unit 18B changes “113, 88, 143” designated by the RGB value as FontColor in C102 as the color data of a certain object. Specifically, the gradation value of R (red) and the gradation value of B (blue) are replaced with the gradation value of G (green) and changed to “88, 88, 88” (FIG. 4). (See (B)).

  Note that the monochrome processing method by the conversion unit 18B is not limited to such conversion of gradation values as long as the conversion is monochrome. For example, all of the gradation values of RGB color components indicated as color data may be converted into information of luminance Y. However, among the RGB color components, the G component has the largest contribution to brightness. For this reason, in the present embodiment, the conversion unit 18B performs monochromeization by replacing the R (red) gradation value and the B (blue) gradation value with the G (green) gradation value. Explain the case.

  Then, the conversion unit 18B sends the image data after the color of the color data of the object determined as the color material amount reduction target is converted to monochrome to the color conversion unit 22. For this reason, the color conversion unit 22 receives monochrome image data for the color data of the object determined as the color material amount reduction target.

  The color conversion unit 22 performs rasterization by a known method based on the image data received from the processing unit 18 and the printing method information received from the designation unit 12 and can be formed by the image forming unit 14. Data is converted into data (usually CMYK data). Then, the converted print data is sent to the image forming unit 14.

  The image forming unit 14 is a known image forming apparatus that forms (that is, prints) an image using a toner including a color material, an ink including a color material, or the like. When receiving the printing data, the image forming unit 14 prints an image on the recording medium based on the received printing data.

  Next, image processing by the image processing apparatus 16 of the present embodiment configured as described above will be described. FIG. 6 is a sequence diagram illustrating a procedure of image processing according to the present embodiment.

  First, the designation unit 12 receives printing method information indicating a printing method (step S100). Then, the designation unit 12 sends the received printing method information to the processing unit 18.

  In step S <b> 100, the designation unit 12 receives printing method information including information indicating presence / absence of aggregate printing, the number of aggregations, presence / absence of variable magnification printing, variable magnification, and presence / absence of color material amount reduction processing. These pieces of information are input to the designation unit 12 when an input screen for inputting the various information is displayed on the designation unit 12 and each item displayed on the display screen is selected and instructed by the user.

  For example, the input screen shown in FIG. The user indicates the presence / absence of aggregated printing by instructing the setting unit 40 for setting the presence / absence of aggregated printing and the number of aggregations displayed on the input screen displayed on the designation unit 12 via a mouse or a touch panel. And the aggregation number. In the example shown in FIG. 7, there is shown a case in which aggregate printing is performed and the aggregation number “2” (two pages of image data are printed on one page of the recording medium) is designated.

  Further, for example, the input screen shown in FIG. The user operates the setting unit 42 for designating the presence / absence of magnification / magnification printing and the magnification / magnification shown in the input screen displayed on the designation unit 12 by operating the mouse / touch panel, etc. Set the presence or absence and scaling factor. The example shown in FIG. 8 shows a case where scaling printing is performed and a scaling ratio “80%” is designated.

  Further, for example, the input screen shown in FIG. The user reduces the color material amount by operating the setting box 44 for designating the presence / absence of the color material amount reduction process shown on the input screen displayed on the designation unit 12 via a mouse or a touch panel. Set whether or not to process. In the example shown in FIG. 9, the case where the color material amount reduction processing is specified is shown.

  Next, the determination unit 18A determines whether or not the color material amount reduction mode is set (step S102). When the printing method information received from the specifying unit 12 includes information indicating that there is a color material amount reduction process, the determination unit 18A determines that the color material amount reduction mode is in effect (step S102: Yes), and proceeds to step S104. move on.

  On the other hand, when the printing method information received from the specifying unit 12 includes information indicating that there is no color material amount reduction processing, the determination unit 18A determines that the color material amount reduction mode is not set (step S102: No), and the step Proceed to S114.

  Then, the following processing from step S104 to step S110 is repeated for each object by the number of objects in the image data received by the processing unit 18.

  The determination unit 18A calculates a viewing angle with respect to the object in the image data based on the image data and information indicating the aggregation number and the magnification ratio included in the printing method information (step S104).

  Next, the determination unit 18A determines whether or not the object whose viewing angle is calculated in step S104 is a color material amount reduction target based on the calculated viewing angle, image data, printing method information, and limit viewing angle information. Is determined (step S106).

  If the determination unit 18A determines that the object whose viewing angle has been calculated in step S104 is a color material amount reduction target (step S106: Yes), the determination unit 18A proceeds to step S108, and the determination unit 18A calculates the viewing angle in step S104. The identification information for uniquely identifying the object and the reduction target information indicating that the object is the color material amount reduction target are associated with each other and stored in the memory not shown in the determination unit 18A (step S108). .

  On the other hand, when the determination unit 18A determines that the object whose viewing angle has been calculated in step S104 is not a color material amount reduction target (step S106: No), the determination unit 18A proceeds to step S110, and the determination unit 18A performs the viewing angle in step S104. The identification information for uniquely identifying the calculated object and the non-reduction information indicating that the object is not the color material amount reduction target are associated with each other and stored in a memory (not shown) of the determination unit 18A ( Step S110).

  When the processing from step S104 to step S110 is completed for all objects included in the image data received by the processing unit 18, the determination unit 18A corresponds to the image data, the object identification information, and each object. The reduction target information or non-reduction target information to be sent is sent to the conversion unit 18B.

  The conversion unit 18B performs monochrome processing (step S112). Specifically, the conversion unit 18B performs the above-described monochrome processing on the color data of the object associated with the reduction target information among the objects in the image data received from the determination unit 18A.

  Then, the conversion unit 18 </ b> B sends the image data after the monochrome process is performed on the color data of the object associated with the reduction target information to the color conversion unit 22.

  The color conversion unit 22 performs rasterization by a known method based on the image data described in the page description language after the monochrome processing and the information indicating the scaling factor and the aggregation number included in the printing method information. After being converted into an image forming signal, it is sent to the image forming unit 14 (steps S114 to S120).

  Specifically, the color conversion unit 22 determines whether to perform collective printing (step S114). The color conversion unit 22 determines to perform aggregate printing when the print method information includes information indicating that aggregate printing is present (step S114: Yes). Next, the color conversion unit 22 performs aggregation processing on the image data by a known method (step S116). Then, the process proceeds to step S118. On the other hand, if the printing method information includes information indicating that there is no aggregated printing, the color conversion unit 22 determines that aggregate printing is not performed (step S114: No), and proceeds to step S118.

  Next, the color conversion unit 22 determines whether or not to perform variable magnification printing (step S118). When the printing method information includes information indicating the presence of scaling printing, the color conversion unit 22 determines to perform scaling printing (step S118: Yes). Next, the color conversion unit 22 performs a scaling process on the image data by a known method (step S120). On the other hand, when the printing method information includes information indicating no scaling printing, the color conversion unit 22 determines that scaling printing is not performed (step S118: No). Then, the color conversion unit 22 converts the signal into an image forming signal and sends the converted image data to the image forming unit 14, and then ends this routine.

  As described above, according to the image processing apparatus 16 of the present embodiment, the viewing angle with respect to the object when formed on the recording medium is calculated based on the aggregation number and the scaling factor set as the printing method. Then, the image processing device 16 determines an object whose calculated viewing angle is less than the limit viewing angle information as a color material amount reduction target, and monochromeizes the object determined as a color material amount reduction target as a color material amount reduction process. Process.

  Therefore, according to the image processing apparatus 16 of the present embodiment, among the objects in the image data, the object is printed on the recording medium with a size less than the limit viewing angle at which a person can perceive the color by aggregate printing or scaling printing. The object can be printed in monochrome.

  Therefore, according to the image processing apparatus 16 of the present embodiment, it is possible to effectively suppress the amount of color material used according to the size of the object when formed on the recording medium.

(Second Embodiment)
In the first embodiment, the processing unit 18 described the case where the color of the color data of the object determined as the color material amount reduction target is converted into monochrome (achromatic color) as the color material usage reduction process. .

  In the present embodiment, the processing unit 18 (in this embodiment, the processing unit 19, see FIG. 10) uses the color data of the object determined as the color material amount reduction target as the color material usage reduction process. A case of primary colorization will be described. The “primary color” referred to here indicates a primary color based on a chromatic color. The term “primary colorization” refers to the color of one color material among chromatic color materials (for example, C (cyan), M (magenta), and Y (yellow)) used in the image forming unit 14. This indicates that the color data shown in the image data is converted into the color to be reproduced (the color expressed in the image data). For example, color data of R (red), G (green), and B (blue) is converted into color data that includes only a G (green) component, which is color data for reproduction with a single color of C (cyan).

  As shown in FIG. 10, the image forming apparatus 11 of this embodiment includes an image forming unit 14 and an image processing device 17. The image processing device 17 includes a designation unit 12, a processing unit 19, and a storage unit 20. The functions and configurations of the image forming unit 14, the color conversion unit 22, the specifying unit 12, and the storage unit 20 are the same as those in the first embodiment.

  The processing unit 19 includes a determination unit 19A and a conversion unit 19B.

  As with the determination unit 18A, the determination unit 19A is a color material amount reduction object for each of one or more objects included in the image data based on the image data, the printing method information, and the limit viewing angle information. It is determined whether or not. Similarly to the conversion unit 18B, the conversion unit 19B changes the color data of the object so as to reduce the color material usage amount of the object determined by the determination unit 19A as the color material amount reduction target.

  In the determination unit 19A, in addition to the image data received by the processing unit 19 and the determination result (object identification information in the image data and reduction target information or non-reduction target information corresponding to each object), the determination unit 19A further Information indicating the hue angle H of the HSV space is sent to the conversion unit 19B.

  The conversion unit 19B performs primary color instead of monochrome.

  Hereinafter, differences between the determination unit 19A and the conversion unit 19B from the determination unit 18A and the conversion unit 18B will be mainly described.

  The determination unit 19A further calculates the hue angle H of each object in the HSV space.

  First, the determination unit 19A calculates the ratio (ratio) of each color component in each object from the gradation value of each color component of RGB, which is the color data of each object indicated in the image data. Specifically, the determination unit 19A calculates the ratio (ratio) of RGB color components in each object using the following formulas (3) to (5).

R ′ = R / 255 Formula (3)
G ′ = G / 255 Formula (4)
B ′ = B / 255 (5)

  In Equation (3), R represents the gradation value of the R component indicated in the image data, and R ′ represents the ratio of the R component. In Expression (4), G represents the gradation value of the G component indicated in the image data, and G ′ represents the ratio of the G component. In Expression (5), B represents the gradation value of the B component indicated in the image data, and B ′ represents the ratio of the B component.

  Next, the determination unit 19A obtains, for each object, the maximum value and the minimum value among the proportions (ratio) of RGB color components in each object using the following formulas (6) to (7). .

MAX = max (R ′, G ′, B ′) (6)
MIN = min (R ′, G ′, B ′) (7)

  In Expression (6), MAX represents the maximum value among the ratios (ratio) of RGB color components in each object. (max (R ′, G ′, B ′) is a function that extracts the largest value among R ′, G ′, and B ′. In Equation (7), MIN represents each object. Represents the minimum value of the ratios (ratio) of the RGB color components in min., And min (R ′, G ′, B ′) is the smallest value among R ′, G ′, B ′. The function to extract.

  Next, when the color component having the maximum color component ratio calculated by the above equation (6) is R (red), the determination unit 19A uses the following equation (8) to calculate the HSV of the object. Find the hue angle H of the space.

  H = 60 × (G′−B ′) / (MAX−MIN) +0 (8)

On the other hand, when the color component having the maximum color component ratio calculated by the above equation (6) is G (green), the determination unit 19A uses the following equation (9) to calculate the HSV of the object. Find the hue angle H of the space.
H = 60 × (B′−R ′) / (MAX−MIN) +120 (9)

  On the other hand, when the color component having the maximum color component ratio calculated by the above equation (6) is B (blue), the determination unit 19A uses the following equation (10) to calculate the HSV of the object. Find the hue angle H of the space.

  H = 60 × (R′−G ′) / (MAX−MIN) +240 Formula (10)

  For example, when the image data is the image data shown in FIG. 4A, the determination unit 19A determines the RGB gradation value “113, 88, 143, which is the color data indicated by C102 in FIG. 4A. ”To calculate the ratio (ratio) of RGB color components.

R ′ = 113 / 255≈0.44
G ′ = 88 / 255≈0.35
B ′ = 143 / 255≈0.56

  Next, the determination unit 19A calculates the maximum value and the minimum value among the ratios of RGB color components for the object corresponding to the color data indicated by C102 in FIG.

MAX = max (0.44, 0.35, 0.56) = 0.56
MIN = min (0.44, 0.35, 0.56) = 0.35

  Further, the determination unit 19A determines that the color component having the maximum color component ratio is B (blue) for the object corresponding to the color data indicated by C102 in FIG. 0.56 "), the hue angle H (deg) of the object in the HSV space is obtained by the following formula using the above formula (10).

  H = 60 × (0.44-0.35) / (0.56-0.35) + 240≈266 (deg.)

  Next, the determination unit 19A determines whether each object in the image data is a color material amount reduction target in the same manner as the determination unit 18A in the first embodiment. That is, the determination unit 19A determines an object whose viewing angle with respect to each object when formed on the recording medium is less than the limit viewing angle information corresponding to the hue of each object as a color material amount reduction target. Then, the determination unit 19A sends the image data, determination results of all the objects included in the image data, and information indicating the hue angle H of the HSV space of each object to the conversion unit 19B.

  Based on the image data received from the determination unit 19A, the determination result, and the information indicating the hue angle H of the HSV space of each object, the conversion unit 19B determines the object in the image data as a color material amount reduction target. Only for the selected object, the color data of the object is changed so as to reduce the color material usage amount.

  As the color material usage amount reduction process, in this embodiment, the conversion unit 19B primary-colors the color of the color data of the object determined as the color material amount reduction target. Specifically, the conversion unit 19B determines that the color material amount is to be reduced so that the color data is reproduced with the primary color of one type of chromatic color material used in the image forming unit 14. The color data of the specified object. At this time, based on the hue angle H of each object determined as the color material amount reduction target, the conversion unit 19B becomes color data that is reproduced with a primary color using one type of color material corresponding to the hue angle H. To convert the color data.

  For example, if the hue angle H of the object determined as the color material amount reduction target is 240 deg. 279 deg. Suppose that: Then, it is assumed that the color data indicated in the image data of the object is “113, 88, 143” designated by RGB values as FontColor in C102 in FIG. 4A. The hue angle H240deg. 279 deg. The hue corresponding to the following is B (blue). Therefore, the conversion unit 19B changes the color data of the object to “0, 143, 143” so that the object is reproduced with a primary color of C (cyan) that is a color material color corresponding to B (blue). To "". That is, the B (blue) component intensity is regarded as the C (cyan) component intensity, and the gradation values of the other components are set to “0”.

  Similarly, the hue angle H of the object determined as the color material amount reduction target is 270 deg. 330 deg. Suppose that: In this case, the conversion unit 19B converts the color data of the object so that the object is reproduced with the primary color M (magenta) that is the color material color.

  When the hue angle H of the object determined as the color material amount reduction target corresponds to yellow, when the object is reproduced with the primary color of yellow (Y) as the color material color, the object is formed on the recording medium. The visibility of the object is reduced. In particular, when the recording medium is white, an object printed with a yellow primary color is difficult to see.

  Therefore, when the hue angle H of the object determined as the color material amount reduction target corresponds to yellow, the conversion unit 19B converts the color of the color data of the object determined as the color material amount reduction target to monochrome It is preferable to do.

  As described above, according to the image processing apparatus 17 of the present embodiment, the object in the image data when the object in the image data is formed on the recording medium based on the aggregation number and the scaling factor set as the printing method. The viewing angle is calculated. Then, the image processing device 17 determines an object whose calculated viewing angle is less than the limit viewing angle information as a color material amount reduction target, and the object determined as the color material amount reduction target is a chromatic color as color material amount reduction processing. The primary colorization process is performed.

  Therefore, according to the image processing apparatus 17 of the present embodiment, among objects in the image data, the object is printed on the recording medium with a size less than the limit viewing angle at which a person can perceive the color by aggregate printing or scaling printing. Objects can be printed with primary colors.

  Therefore, according to the image processing apparatus 17 of the present embodiment, it is possible to effectively suppress the amount of color material used according to the size of the object when formed on the recording medium.

  In the first embodiment and the second embodiment, when the storage unit 20 stores in advance the limit viewing angle information indicating the limit viewing angle at which a person perceives the hue, in association with the hue information. Explained.

  However, the specification unit 12 may further receive the limit viewing angle information, and the received limit viewing angle information may be stored in the storage unit 20.

  In this case, the limit viewing angle information may be set by displaying the input screen shown in FIG. 11 on the designation unit 12 and instructing the user to perform an operation via a mouse, a touch panel, or the like. The input screen shown in FIG. 11 displays the input screen shown in FIG. 9 on the designation unit 12, and the color material amount reduction processing is performed when the user gives an operation instruction to the setting box 44 via a mouse, a touch panel, or the like. May be displayed on the designation unit 12 when.

  Then, when the input screen shown in FIG. 11 is displayed on the designation unit 12, the user can select black characters and color characters (for example, blue, green, red 3) having different sizes from a predetermined distance (for example, about 50 cm). Observe the set of seeds, and select a set of characters with a size that makes the difference in color between black characters and colored characters almost indistinguishable. Thereby, the designation unit 12 may receive limit viewing angle information indicating the limit viewing angle.

  And the memory | storage part 20 should just memorize | store the limit visual angle information received in the designation | designated part 12. FIG.

  As described above, the ratio of the number of general cones is generally clear, but on the other hand, there is a certain percentage of people with visual characteristics (color vision characteristics) that do not have specific cones. Has also been revealed. Therefore, in this way, even if the person who is difficult to feel the color of a specific color by receiving the limit viewing angle information in the designation unit 12 and appropriately updating the limit viewing angle information stored in the storage unit 20, The color material amount can be appropriately reduced in accordance with the visual characteristics of the user.

  Next, the hardware configuration of the image processing device 16 and the image processing device 17 capable of executing the program for realizing the image processing method of the first embodiment and the second embodiment will be described.

  FIG. 12 shows a hardware configuration of the image processing apparatus 16 capable of executing the program for realizing the image processing method and the computer 400 as the image processing apparatus 17 according to the first embodiment and the second embodiment. It is a block diagram.

  As shown in FIG. 12, a computer 400 includes a program reading device 400A, a CPU (Central Processing Unit) 400B, a RAM (Random Access Memory) 400C, a ROM (Read Only Memory) 400D, a hard disk 400E, a NIC. (Network Interface Card) 400F, a mouse 400G, a keyboard 400H, a display 411 that displays image data and allows a user to input information by directly touching the screen, and a printer 412. Note that the image processing device 16 and the image processing device 17 according to the present embodiment can be realized by, for example, a workstation or a personal computer. The processing function performed by the CPU 400B can be provided in the form of, for example, a software package, specifically, an information recording medium such as a CD-ROM or a magnetic disk. For this reason, in the example shown in FIG. 12, when an information recording medium is set, a medium driving device (not shown) that drives the information recording medium is provided.

  In the case of the above configuration, the function of the designation unit 12 (see FIGS. 1 and 10) can be performed by the mouse 400G, the keyboard 400H, or the display 411. The function of the image forming unit 14 (see FIGS. 1 and 10) can be performed by the printer 412.

  An image processing program for executing a sequence showing a procedure of image processing, which is executed by the image processing device 16 and the image processing device 17 of the first embodiment and the second embodiment, is in an installable format or An executable file is recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk).

  Further, the image processing program executed by the image processing apparatus 16 and the image processing apparatus 17 of the first embodiment and the second embodiment is stored on a computer connected to a network such as the Internet, and is transmitted via the network. You may comprise so that it may provide by making it download. Further, the image processing program executed by the image processing device 16 and the image processing device 17 of the first embodiment and the second embodiment may be provided or distributed via a network such as the Internet. .

  In addition, the image processing program executed by the image processing device 16 and the image processing device 17 of the first embodiment and the second embodiment may be provided by being incorporated in the ROM 400D in advance.

  The image processing program executed by the image processing device 16 and the image processing device 17 according to the first embodiment and the second embodiment includes the above-described units (designation unit, processing unit (determination unit, conversion unit), storage) Module, and a color conversion unit). As actual hardware, a CPU (processor) reads out and executes an image processing program from the storage medium, so that each unit is on a main storage device such as the RAM 400C. The designation unit, processing unit (determination unit, conversion unit), storage unit, and color conversion unit are generated on the main storage device.

  In the above embodiment, the image forming apparatus has been described as an example applied to a printing apparatus. However, a multifunction machine or a copying apparatus having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function. Any image forming apparatus having a printing function, such as a facsimile machine, can be applied.

DESCRIPTION OF SYMBOLS 12 Designation part 14 Image formation part 16, 17 Image processing apparatus 18, 19 Processing part 18A, 19A Determination part 18B, 19B Conversion part 20 Storage part 22 Color conversion part

JP 2008-28921 A

Claims (6)

Designating means for receiving printing method information including at least one of the aggregation number and the scaling ratio;
Storage means for preliminarily storing limit viewing angle information indicating a limit viewing angle at which a person can perceive color;
Based on image data including color data of one or more objects and the printing method information, a viewing angle with respect to the object when printed on a recording medium is calculated, and an object whose calculated viewing angle is equal to or less than the limit viewing angle information. Determination means for determining as a color material amount reduction target;
Conversion means for converting the color data of the object in the image data so as to reduce the color material usage of the object determined as the color material amount reduction target among the objects in the image data;
An image processing apparatus. The storage means stores the limit viewing angle information in association with color data,
The determination means calculates a viewing angle for the object when printed on a recording medium based on the image data and the printing method information, and the calculated viewing angle corresponds to the limit viewing angle corresponding to the color data of each object. The image processing apparatus according to claim 1, wherein an object that is equal to or less than information is determined as a color material amount reduction target.   The image processing apparatus according to claim 1, wherein the conversion unit converts color data of an object determined as the color material amount reduction target into monochrome color data.   The conversion unit converts the color data of the object so that the color of the object determined as the color material amount reduction target is a primary color corresponding to the hue angle of the HSV color space indicated by the color data of the object. The image processing apparatus according to claim 1 or 2. An image processing method executed by an image processing apparatus,
The image processing apparatus includes storage means that stores in advance limit viewing angle information indicating a limit viewing angle at which a person can perceive color,
Receiving printing method information including at least one of an aggregation number and a scaling factor;
Based on image data including color data of one or more objects and the printing method information, a viewing angle with respect to the object when printed on a recording medium is calculated, and an object whose calculated viewing angle is equal to or less than the limit viewing angle information. Determining as a color material amount reduction target;
Converting the color data of the object in the image data so as to reduce the color material usage of the object determined as the color material amount reduction target among the objects in the image data;
An image processing method including: An image processing program for causing a computer to execute,
The computer includes storage means for preliminarily storing limit viewing angle information indicating a limit viewing angle at which a person can perceive color,
Receiving printing method information including at least one of an aggregation number and a scaling factor;
Based on image data including color data of one or more objects and the printing method information, a viewing angle with respect to the object when printed on a recording medium is calculated, and an object whose calculated viewing angle is equal to or less than the limit viewing angle information. Determining as a color material amount reduction target;
Converting the color data of the object in the image data so as to reduce the color material usage of the object determined as the color material amount reduction target among the objects in the image data;
An image processing program for causing the computer to execute.

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