JP2013098618A - Image processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus capable of easily setting desired color correction.SOLUTION: A pixel extraction part 401 extracts a pixel which belongs to a color range specified in advance from correction target image data. A target color selection receiving part 403 receives selection of a target color by a user from plural target colors stored in a target color holding part 402. A color correction execution part 404 executes color correction to image data to be corrected based on a pixel color extracted by the pixel extraction part 401 and a target color selected through the target color selection receiving part 403. The target color extract part 406 extracts a target color to be registered from image data for target color registration held in a registration image holding part 405. A target color registration part 408 registers in the target color holding part 402 the target color to be registered extracted by the target color extract part 406 in association with a new color range input to a color range input part 407.

Description

  The present invention relates to an image processing apparatus that performs color correction on image data.

  In recent years, devices capable of color printing have become common in image forming apparatuses such as copiers and multifunction peripherals. This type of image forming apparatus realizes color printing by combining, for example, four color toners and inks such as C (cyan), M (magenta), Y (yellow), and K (black).

  Many of such image forming apparatuses have a function of performing color correction on image data. In the first place, image forming apparatuses are required to faithfully reproduce the colors of the original document, but in recent years, images including photographs have been printed, and the colors are converted to colors that people feel desirable. This is because it has begun to be requested. Specifically, converting a color into a color that a person feels preferable means to reproduce a so-called memory color. Memory colors are, for example, human skin, blue sky, green vegetation, red sunset, etc., and are closer to colors stored by humans than to reproduce colors that are faithful to the original. It is a color that favors color reproduction.

  Such memory colors have individual differences in preferred colors. For this reason, various methods have been proposed for appropriately providing colors that are felt to be preferable in the image forming apparatus (for example, see Patent Documents 1-3).

  For example, Patent Document 1 described later prints a color adjustment image composed of a plurality of thumbnail images whose hues are changed little by little, and inputs a number for specifying a thumbnail image selected from the printed color adjustment images. An image processing apparatus is disclosed that allows a user to select a preferred color correction and reflect the color correction in image processing.

  Patent Document 2 and Patent Document 3 disclose a technique for causing a user to select a color correction condition by displaying a plurality of images on which the same image is subjected to different color corrections on the same screen and selecting the images. doing.

Japanese Unexamined Patent Publication No. 2009-200741 Japanese Patent Laid-Open No. 11-032227 JP-A-11-098374

  With the technology disclosed in Patent Literatures 1-3, if a preferred color correction is included in the presented color correction candidates, the user can easily select the color correction. However, when a preferred color correction is not included in the presented color correction candidates, a complicated operation or the like is required to obtain the preferred color correction, and the user cannot easily set a desired color correction. .

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an image processing apparatus capable of easily setting desired color correction.

  In order to achieve the above object, the image processing apparatus according to the present invention employs the following technical means. That is, the present invention is an image processing apparatus that performs color correction on image data, and includes a pixel extraction unit, a target color holding unit, a target color selection receiving unit, a color correction performing unit, a registration image holding unit, a target A color extraction unit, a color range input unit, and a target color registration unit are provided. The pixel extraction unit extracts pixels belonging to a color range designated in advance from the image data to be corrected. The target color holding unit stores a plurality of target colors in association with a color range designated in advance. The target color selection receiving unit receives selection of one target color by the user from a plurality of target colors stored in the target color holding unit. The color correction execution unit performs color correction on the image data to be corrected based on the pixel color extracted by the pixel extraction unit and the target color selected through the target color selection receiving unit. The registration image holding unit holds image data including a target color to be registered. The target color extraction unit extracts a target color to be registered from the image data held in the registration image holding unit. The new color range associated with the registration target color extracted by the target color extraction unit is input to the color range input unit. The target color registration unit registers the target color to be registered extracted by the target color extraction unit in the target color holding unit in association with the new color range input to the color range input unit.

  According to this image processing apparatus, the target color can be registered using the image data. That is, the color included in the image visually confirmed by the user can be registered as the target color. In addition, it is possible to set a color range to be subjected to color correction to a target color to be registered. Therefore, even a color such as a memory color that is not set in the image processing apparatus can register a user's favorite color as a target color. As a result, when color correction is performed, the user can easily perform color correction to a favorite color.

  In this image processing apparatus, the target color extraction unit extracts pixels in a region of image data designated in advance, displays the color of the extracted pixels as candidates for a registration target target color, and registers the target color to be registered by the user. It may be configured to accept the selection. In this configuration, when a plurality of colors are included in the image data used for registering the target color, the user can select a desired target color from the presented target color candidates. That is, the user's favorite color can be registered as a target color very easily and reliably.

The image processing apparatus may further include a determination unit that determines whether the target color to be registered extracted by the target color extraction unit belongs to a color range already registered in the target color holding unit. In this case, when the determination unit determines that the color does not belong to the already registered color range, the target color registration unit inputs the target color to be registered extracted by the target color extraction unit to the color range input unit The new color range is registered in the target color holding unit in association with the new color range. Alternatively, the image processing apparatus determines whether the registration target color extracted by the target color extraction unit satisfies a color difference condition specified in advance for the target color already registered in the target color holding unit. You may further provide the determination part. In this case, when the determination unit determines that the color difference condition is satisfied, the target color registration unit uses the target color to be registered extracted by the target color extraction unit as a new color range input to the color range input unit. Are registered in the target color holding unit. As the color difference condition, for example, the color difference between the target color already stored in the target color holding unit and the registration target target color in the CIE L ^* C ^* h color space can be used. .

  In these configurations, an approximate target color having a small color difference in the color space is not registered as a target color in a different color range. As a result, when performing color correction, it is possible to prevent a situation where it is difficult to select color correction because a number of approximate color ranges are presented to the user.

  According to the present invention, the user can easily set desired color correction in the image processing apparatus. In addition, desired color correction can be easily performed.

1 is a schematic configuration diagram showing the overall configuration of a multifunction machine according to an embodiment of the present invention. 1 is a schematic diagram showing an operation panel of a multifunction machine according to an embodiment of the present invention. The figure which shows the hardware constitutions of the multifunctional device in one Embodiment of this invention. 1 is a functional block diagram showing a multifunction machine according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating an example of a color correction procedure performed by the multifunction peripheral according to the embodiment of the present invention. The figure which shows an example of the color range selection screen which the multifunctional machine in one Embodiment of this invention displays The figure which shows an example of the target color selection screen which the multifunctional device in one Embodiment of this invention displays The flowchart which shows an example of the target color registration procedure which the multifunctional machine in one Embodiment of this invention implements The figure which shows an example of the target color position designation | designated screen which the multifunctional device in one Embodiment of this invention displays The figure which shows an example of the color range input screen which the multifunctional device in one Embodiment of this invention displays The figure which shows an example of the color range selection screen which the multifunctional machine in one Embodiment of this invention displays The figure which shows an example of the target color selection screen which the multifunctional device in one Embodiment of this invention displays

  Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings. In the following, the present invention is embodied as a digital multifunction machine.

  FIG. 1 is a schematic configuration diagram illustrating an example of the overall configuration of a digital multifunction peripheral according to the present embodiment. As shown in FIG. 1, the multifunction peripheral 100 includes a main body 101 including an image reading unit 120 and an image forming unit 140, and a platen cover 102 attached above the main body 101. A document table 103 is provided on the upper surface of the main body 101, and the document table 103 is opened and closed by a platen cover 102. Further, the platen cover 102 includes a document conveying device 110.

  An image reading unit 120 is provided below the document table 103. The image reading unit 120 reads an image of a document with the scanning optical system 121 and generates digital data (image data) of the image. The document can be placed on the document table 103 or the document transport device 110. The scanning optical system 121 includes a first carriage 122, a second carriage 123, and a condenser lens 124. The first carriage 122 is provided with a linear light source 131 and a mirror 132, and the second carriage 123 is provided with mirrors 133 and 134. The light source 131 illuminates the document. The mirrors 132, 133, and 134 guide reflected light from the document to the condenser lens 124, and the condenser lens 124 forms an optical image on the light receiving surface of the line image sensor 125.

  In the scanning optical system 121, the first carriage 122 and the second carriage 123 are provided so as to be able to reciprocate in the sub-scanning direction 135. By moving the first carriage 122 and the second carriage 123 in the sub-scanning direction 135, the image of the document placed on the document table 103 can be read by the image sensor 125. When reading an image of a document set on the document conveying device 110, the image reading unit 120 temporarily fixes the first carriage 122 and the second carriage 123 according to the image reading position, and passes the image reading position. Are read by the image sensor 125. The image sensor 125 generates image data of a document corresponding to, for example, each color of R (red), G (green), and B (blue) from the light image incident on the light receiving surface. The generated image data can be printed on paper in the image forming unit 140. Further, the data can be transmitted to another device (not shown) through the network 162 by the network adapter 161.

  The image forming unit 140 prints image data obtained by the image reading unit 120 or image data received from another device (not shown) connected to the network 162 on a sheet. The image forming unit 140 includes a photosensitive drum 141. The photosensitive drum 141 rotates in one direction at a constant speed. Around the photosensitive drum 141, a charger 142, an exposure unit 143, a developing unit 144, and an intermediate transfer belt 145 are arranged in this order from the upstream side in the rotation direction. The charger 142 uniformly charges the surface of the photosensitive drum 141. The exposure device 143 irradiates the surface of the uniformly charged photoconductor drum 141 with light according to the image data, and forms an electrostatic latent image on the photoconductor drum 141. The developing device 144 attaches toner to the electrostatic latent image and forms a toner image on the photosensitive drum 141. The intermediate transfer belt 145 transfers the toner image on the photosensitive drum 141 onto a sheet. When the image data is a color image, the intermediate transfer belt 145 transfers each color toner image onto the same sheet. The RGB color image is converted into C (cyan), M (magenta), Y (yellow), and K (black) format image data, and the image data of each color is input to the exposure unit 143.

  The image forming unit 140 feeds paper from the manual feed tray 151, the paper feed cassettes 152, 153, and 154 to the transfer unit between the intermediate transfer belt 145 and the transfer roller 146. Various sizes of paper can be placed or stored in the manual feed tray 151 and the paper feed cassettes 152, 153, and 154. The image forming unit 140 selects a sheet specified by the user or a sheet corresponding to the automatically detected document size, and feeds the selected sheet from the manual feed tray 151 or the cassettes 152, 153, and 154 by the feeding roller 155. . The fed paper is transported to the transfer section by transport rollers 156 and registration rollers 157. The sheet on which the toner image is transferred is conveyed to the fixing device 148 by the conveyance belt 147. The fixing device 148 has a fixing roller 158 and a pressure roller 159 with a built-in heater, and fixes the toner image on the sheet by heat and pressing force. The image forming unit 140 discharges the sheet that has passed through the fixing device 148 to the discharge tray 149.

  FIG. 2 is a diagram illustrating an example of an appearance of an operation panel included in the multifunction peripheral. The user can use the operation panel 200 to give the MFP 100 a start of copying and other instructions, and to confirm the status and settings of the MFP 100. On the operation panel 200, a display 201 with a touch panel and operation keys 203 are arranged. The display 201 includes a display surface including a liquid crystal display that displays operation buttons, messages, and the like, and a sensor that detects a pressed position on the display surface. The detection method of a press position is not specifically limited. Any method such as a resistance film method, a capacitance method, a surface acoustic wave method, and an electromagnetic wave method can be employed. The user can input through the display 201 using his / her finger or the touch pen 202.

  The display 201 displays an operation screen having a button display unit 204, a message display unit 205, and a status display unit 206. A plurality of tabs 208 are prepared in the button display unit 204, and operation buttons corresponding to the tab category are arranged on each tab. The “easy setting” tab has operation buttons used for basic setting. In the example of FIG. 2, operation buttons for setting paper size, copy magnification, density, printing surface, page aggregation, and post-processing are arranged. For example, when the user performs an operation of pressing the “density” button 207, a pop-up screen having selection buttons such as “light”, “normal”, and “dark” for selecting the density is displayed over the operation button. The density is set by the user's selection (pressing). In the example of FIG. 2, in addition to the “easy setting” tab, a “document / paper / finish” tab, a “color / image quality” tab, a “layout / edit” tab, and an “application / others” tab are also provided. The user can switch to the display of these tabs by performing an operation of selecting the tab button 208. While one tab is selected, other tabs and their elements are hidden on the operation screen. In the multi-function device 100, color correction described later can be executed by pressing a “one-touch image quality adjustment” button included in the “color / image quality” tab. Further, target color registration described later can be executed by pressing a “target color registration” button included in the “color / image quality” tab.

  The message display unit 205 displays a message notifying the user of settings such as whether copying is possible and the number of copies. The status display unit 206 displays device status information as necessary. In this display, detection results of various sensors included in the multifunction peripheral 100 are reflected. The device status information means a message that notifies the user of a warning that prompts the user to respond to an abnormality although the device is in an operable state. For example, the fact that the remaining amount of paper is low, the document platen 103 is dirty, and the facsimile document is stored in the memory when the facsimile memory reception is set is included. Further, the device status information may include out-of-paper, conveyance jam, and the like.

  The operation keys 203 include a main power key 209, a numeric keypad 210, a start key 211, a clear key 212, and the like. For example, the power key 209 is used to switch the MFP 100 on and off. The numeric keypad 210 can be used for specifying the number of copies and setting the copy magnification. When the user makes these settings, the multi-function device 100 displays a message such as “Can be copied (with settings)” on the message display unit 205 to notify the user that the settings have been made. The start key 211 is used for a start instruction for copying or image printing. The user operates the clear key 212 when canceling the setting made by the user. Since whether or not the machine accepts the setting by the user can be determined by the above-described message, the clear key 212 may be operated if the setting becomes unnecessary.

  FIG. 3 is a hardware configuration diagram of a control system in the multifunction machine. The multifunction peripheral 100 according to the present embodiment includes a CPU (Central Processing Unit) 301, a RAM (Random Access Memory) 302, a ROM (Read Only Memory) 303, an HDD (Hard Disk Drive) 304, an original transport device 110, and an image reading unit 120. A driver 305 corresponding to each drive unit in the image forming unit 140 is connected via an internal bus 306. The ROM 303, the HDD 304, and the like store programs, and the CPU 301 controls the multifunction peripheral 100 in accordance with the instructions of the control program. For example, the CPU 301 uses the RAM 302 as a work area, and controls the operation of each driving unit by exchanging data and commands with the driver 305. The HDD 304 is also used to store image data obtained by the image reading unit 120 and image data received from other devices through the network adapter 161.

  An operation panel 200 and various sensors 307 are also connected to the internal bus 306. The operation panel 200 receives a user operation and supplies a signal based on the operation to the CPU 301. The display 201 displays the above-described operation screen according to a control signal from the CPU 301. The sensor 307 includes various sensors such as an open / close detection sensor for the platen cover 102, a document detection sensor on the document table 103, a temperature sensor for the fixing device 148, and a detection sensor for the conveyed paper or document. The CPU 301 executes, for example, a program stored in the ROM 303 to realize each of the following means (functional blocks) and controls the operation of each means according to signals from these sensors.

  FIG. 4 is a functional block diagram of the MFP according to the present embodiment. As illustrated in FIG. 4, the multifunction peripheral 100 according to the present embodiment includes a pixel extraction unit 401, a target color holding unit 402, a target color selection receiving unit 403, a color correction execution unit 404, a registration image holding unit 405, a target color extraction. A unit 406, a color range input unit 407, a target color registration unit 408, a determination unit 409, and a correction target image holding unit 410. The pixel extraction unit 401, the target color holding unit 402, the target color selection receiving unit 403, the color correction execution unit 404, and the correction target image holding unit 410 use the color of pixels belonging to a predetermined color range as the target color in the multifunction machine 100. A function for performing color correction for image data on the image data is realized. In addition, the registration image holding unit 405, the target color extraction unit 406, the color range input unit 407, the target color registration unit 408, and the determination unit 409 register a new target color in the target color holding unit 402 in the multifunction peripheral 100. Realize the function.

The pixel extraction unit 401 extracts pixels belonging to a color range designated in advance (hereinafter also referred to as a designated color range) from the image data to be corrected. For example, the color range can be set as a color that occupies a certain area in the CIE L ^* C ^* h color space, which is a uniform color space. Here, the image data has color information expressed by color components constituting an absolute color space such as sRGB (standard RGB), and can be easily converted into an expression in the CIE L ^* C ^* h color space. It is. Note that when the image data has color information expressed in RGB format having device dependence, the multi-function device 100 converts the color information into color information expressed in an absolute color space.

  Although not particularly limited, in the present embodiment, the correction target image data is temporarily held in the correction target image holding unit 410. Here, the correction target image holding unit 410 is configured as an area in which correction target image data is stored in the image holding unit 411 including a volatile memory such as a RAM. In the present embodiment, a registration image holding unit 405 described later is also provided in the image holding unit 411. The registration image holding unit 405 is configured as an area in which image data including a target color to be registered in the image holding unit 411 (hereinafter referred to as target color registration image data) is stored. When the MFP 100 does not hold the correction target image data and the target color registration image data at the same time, the correction target image holding unit 410 and the registration image holding unit 405 are configured as the same part of the image holding unit 411. You can also.

  Note that image data (correction target image data or target color registration image data) held in the image holding unit 411 is acquired from the image storage unit 412, for example. The image storage unit 412 is a storage area secured in the HDD 304 described above, and stores image data input from the image reading unit 120 and image data input from an external device via the network 161 or the like. Further, the image data input from the image reading unit 120 or the image data input from an external device via the network 161 or the like may be directly stored in the image holding unit 411.

The target color holding unit 402 stores color information of the target color in the color correction performed by the color correction execution unit 404 described in detail below. Here, color coordinates in the CIE L ^* C ^* h color space are stored as color information. In the target color holding unit 402, the target color is stored in association with the color range that can be selected as the specified color range. A plurality of target colors are associated with one color range, and the user selects one target color from among the plurality of target colors, so that the target color in the color correction performed by the color correction execution unit 404 is selected. You can choose. The one target color is selected by the user through the target color selection receiving unit 403.

  Based on the pixel color extracted by the pixel extraction unit 401 and the target color selected through the target color selection receiving unit 403, the color correction execution unit 404 applies correction target image data held by the correction target image holding unit 410 to the correction target image data. Color correction is performed on the image. In the color correction, if all the pixels extracted by the pixel extraction unit 401 are replaced with the selected target color, gradation skip occurs and the image quality is significantly lowered. Therefore, the color correction execution unit 404 responds to the color difference between the pixel color extracted by the pixel extraction unit 401 and the selected target color, that is, the distance between two colors in the uniform color space (or uniform color plane). The occurrence of gradation skip is prevented by calculating the color correction amount. With this correction method, it is possible to realize correction that brings the color of the pixel extracted by the pixel extraction unit 401 closer to the target color.

Specifically, when the color difference is large, the correction amount in the direction toward the target color (hereinafter referred to as a color correction vector) is increased, and when the color difference is small, the color correction vector is decreased. Although not particularly limited, in the present embodiment, one of five correction parameters a1, a2, a3, a4, and a5 (a1 <a2 <a3 <a4 <a5) is selected according to the color difference. A correction parameter is selected, and the magnitude of the color correction vector is calculated by the product of the color difference and the selected correction parameter. In this case, the correction parameter is set as a value between 0 and 1. As described above, in this embodiment, the target color is set as one point in the CIE L ^* C ^* h color space. Therefore, a color correction vector directed to the target color in the CIE L ^* C ^* h color space is calculated as the color correction amount.

The color correction execution unit 404 first corresponds to the selected target color for each pixel extracted by the pixel extraction unit 401 as a pixel belonging to the specified color range from the image data held in the correction target image holding unit 410. The color correction amount to be calculated is calculated by the above-described method. Next, the color correction execution unit 404 changes the color information of each extracted pixel by applying the calculated color correction amount to the color information of each pixel extracted by the pixel extraction unit 401. As described above, the application of the color correction amount is performed based on the color coordinates in the CIE L ^* C ^* h color space. The color correction execution unit 404 obtains corrected image data by changing to color information expressed by color components constituting an absolute color space such as sRGB after application of the color correction amount.

  Next, a configuration that acts to register a new target color in the target color holding unit 402 will be described. As described above, the function of registering a new target color is realized by the registration image holding unit 405, the target color extraction unit 406, the color range input unit 407, the target color registration unit 408, and the determination unit 409.

  The target color extraction unit 406 extracts a target color to be registered from the target color registration image data held in the registration image holding unit 405. As target color registration image data, image data stored in the image storage unit 412, image data input from the image reading unit 120, image data input from an external device via the network 161, or the like is used. Can do.

  The extraction of a new target color can be carried out, for example, by designating a position (point or area) in the target color registration image data by the user. That is, when there is only a single color at the position specified by the user for the target color registration image data, the target color extraction unit 406 extracts the color as a new target color. When there are a plurality of colors at the position specified by the user for the target color registration image data, the target color extraction unit 406 presents the plurality of colors as target color candidates to the user, and the displayed target color The user designates a color to be extracted as a new target color from the candidates. Alternatively, the target color extraction unit 406 may count the number of pixels for each target color candidate, and automatically extract the color having the largest number of pixels as a new target color. When the extracted target color candidates are presented to the user, it is not necessary to present all of them, and a part (for example, about three types) may be presented in descending order of the number of pixels.

  Further, as described above, the target color holding unit 402 holds the target color in association with the color range, and the new target color needs to be held in association with the color range. In the present embodiment, the user inputs a color range associated with the new target color through the color range input unit 407.

  The determination unit 409 determines whether the target color to be registered extracted by the target color extraction unit 406 belongs to a color range already registered in the target color holding unit 402. When the target color registration unit 408 determines that the registration target color extracted by the target color extraction unit 406 by the determination unit 409 does not belong to the already registered color range, the target color registration unit 408 The new color range input to the color range input unit 407 is registered in the target color holding unit 402 in association with the new color range.

  In the multifunction device 100, an instruction such as selection by the user is input by an operation on the operation panel 200 including the display 201 (pressing of the operation key 203 or pressing of the display 201). The display 201 recognizes the operation content of the user based on the coordinates of the pressed position detected by the sensor that detects the pressed position of the display 201 and the coordinates of the screen elements such as operation buttons displayed on the display 201.

  Next, processing performed by the multifunction machine 100 will be described. In the following, the color correction procedure will be described first, and then the target color registration procedure will be described.

  FIG. 5 is a flowchart illustrating an example of a color correction procedure performed by the multifunction peripheral 100. The procedure proceeds with, for example, a color correction instruction input by the user as a trigger. Note that the color correction instruction is input to the multi-function peripheral 100 when the user presses the “one-touch image quality adjustment” button included in the “color / image quality” tab of the operation screen as described above.

  At this time, the pixel extraction unit 401 displays a screen requesting image data designation on the display 201, and waits until the designation of image data by the user is completed (No in step S501). The user designates image data to be color corrected. The designation method is not particularly limited. For example, when the image data stored in the image storage unit 412 is designated as image data to be color-corrected, a list of image data stored in the image storage unit 412 is displayed on the display 201 and read from the list. What is necessary is just to select image data. The selected image data is read from the image storage unit 412 and held in the correction target image holding unit 410. The correction target image data can also be read by the image reading unit 120. In this case, the user sets a document to be corrected on the document tray of the document feeder 110 and instructs the multifunction device 100 to start reading by pressing the start key or the like. The image data read by the image reading unit 120 is held in the correction target image holding unit 410. If the same color correction is applied, the image data held in the correction target image holding unit 410 may be a plurality of pages, but here, an explanation will be given based on an example of one page.

  When the specification of the image data is completed, the pixel extraction unit 401 displays a screen requesting selection of a color range (specified color range) to be subjected to color correction in the correction target image data on the display 201, and the user can select a color range. It waits until selection is completed (step S501 Yes, S502 No). The user selects a color to be corrected.

  FIG. 6 is a diagram showing an example of a color range selection screen displayed on the display 201 at this time. In this example, the color range selection screen 601 includes selection buttons 602 to 604 that are used to select a color range, and a “return” button 605 that is used to cancel the selection and return to designation of image data. In FIG. 6, as a selection button, a “portrait photograph” button 602 corresponding to a flesh color that is one of the memory colors, a “landscape photograph (blue)” button 603 corresponding to one of the memory colors, and a memory color In this example, a “landscape photograph (green)” button 604 corresponding to one green is shown. When the user selects one of the selection buttons 602 to 604, the pixel extraction unit 401 sets the color range associated with the selected button (memory color) as the designated color range used for pixel extraction.

For example, in FIG. 6, when the user selects a “landscape photograph (blue)” button 603, the pixel extraction unit 401 displays a blue color range (L ^* : 20 to 80, C ^* : 5) associated with the button. To 55, Hue: 190 to 330 °), it is set to a state of extracting pixels of colors belonging to. Note that such a color range is registered in advance in the pixel extraction unit 401 in association with the selection buttons 602 to 604.

  Receiving the color range specification, the pixel extraction unit 401 notifies the target color selection receiving unit 403 of information indicating the color range (hereinafter referred to as a color range identifier). Receiving the notification, the target color selection receiving unit 403 displays a screen for receiving the selection of the target color by the user on the display 201, and waits until the selection of the target color by the user is completed (No in steps S502, S503, and S504). The target color selection receiving unit 403 displays each target color registered in the target color holding unit 402 in association with the notified color range on the screen.

  FIG. 7 is a diagram showing an example of the target color selection screen displayed on the display 201 at this time. In this example, the target color selection screen 701 includes rectangular images 702 to 704 colored with each target color. In this figure, a rectangular image 702 corresponds to a first target color (hereinafter referred to as “blue 1”), and a rectangular image 703 corresponds to a second target color (hereinafter referred to as “blue 2”). A rectangular image 704 corresponds to a third target color (hereinafter referred to as “blue 3”). In addition, the target color selection screen 701 includes a “blue 1” button 705, a “blue 2” button 706, and a “blue 3” button 707, which are used for selecting a target color corresponding to each rectangular image, and the selection is canceled. A “return” button 708 used for returning to the range selection screen 601 is provided.

  For example, the first target color can be vivid blue, the second target color can be pure blue without green, and the third target color can be green with blue (so-called emerald green). . The other selection buttons on the color range selection screen 601 will be briefly described. The “portrait photograph” button 602 has a target color that is adjusted in the direction of the skin color that is reddish and ruddy, and seems to be tanned. It is possible to associate a target color adjusted in the direction of a flesh color with a good impression and a target color adjusted in the direction of a flesh-white skin color. A “landscape photograph (green)” button 604 has a target color adjusted in a bright green direction, a target color adjusted in a yellow-green direction, and a target color adjusted in a slightly blueish green direction. Can be associated.

  When the user selects any one of the “blue 1” button 705, the “blue 2” button 706, and the “blue 3” button 707 on the target color selection screen 701 shown in FIG. 7, the target color selection receiving unit 403 is selected. The color information of the target color is input to the color correction execution unit 404 (Yes in step S504). For example, in FIG. 7, when the user selects the “blue 2” button 706, the target color selection receiving unit 403 inputs the color information of the target color “blue 2” to the color correction performing unit 404.

  The color correction execution unit 404 to which the color information of the target color has been input notifies the pixel extraction unit 401 of the start of color correction. The pixel extraction unit 401 that has received the notification extracts pixels having colors that belong to the specified color range from the image data held in the correction target image holding unit 410. The pixel extraction unit 401 inputs the extracted pixel color information and position information in the image data of the pixel to the color correction execution unit 404. Upon receiving the input, the color correction execution unit 404 calculates and extracts a color correction amount for each pixel extracted by the above-described method based on the color information of the target color and the color information input from the pixel extraction unit 401. The corrected color information for each pixel is obtained. The color correction execution unit 404 acquires the image data held in the correction target image holding unit 410 and replaces the color of the pixel corresponding to the position information input from the pixel extraction unit 401 with the corrected color. Color correction is executed (step S505).

  The image data after color correction generated by the color correction execution unit 404 as described above is output from the color correction execution unit 404 by being printed in the image forming unit 140 or stored in the image storage unit 412. The

  Next, a target color registration procedure performed by the multifunction peripheral 100 will be described. FIG. 8 is a flowchart illustrating an example of a target color registration procedure performed by the multifunction peripheral 100. Here, an example will be described in which a red color that is not included in any of the color ranges of the “person photograph”, “landscape photograph (blue)”, and “landscape photograph (green)” is registered as a target color. The procedure proceeds with, for example, a target color registration instruction input by the user. As described above, the target color registration instruction is input to the multifunction device 100 when the user presses the “target color registration” button included in the “color / image quality” tab of the operation screen.

  At this time, the target color extraction unit 406 displays a screen requesting image data designation on the display 201, and waits until the designation of image data by the user is completed (No in step S801). The user designates target color registration image data including the target color in the image. The designation method is not particularly limited. For example, when the image data stored in the image storage unit 412 is designated as the target color registration image data, a list of image data stored in the image storage unit 412 is displayed on the display 201 and read from the list. What is necessary is just to select image data. The selected image data is read from the image storage unit 412 and held in the registration image holding unit 405. In this example, image data representing an evening sea is used as target color registration image data. The image includes the sun, sunset sky and sea. The target color registration image data can also be read by the image reading unit 120. In this case, the user sets a document to be registered on the document tray of the document feeder 110 and instructs the multifunction device 100 to start reading by pressing the start key or the like. The image data read by the image reading unit 120 is held in the registration image holding unit 405.

  When the specification of the image data is completed, the target color extraction unit 406 displays on the display 201 a screen requesting specification of the position (point or area) where the target color to be registered exists in the target color registration image data. It waits until the selection of the position by the user is completed (step S801 Yes, S802 No). The user designates the position where the target color to be registered exists.

  FIG. 9 is a diagram showing an example of the target color position designation screen displayed on the display 201 at this time. In this example, the target color position designation screen 901 displays a preview display unit 902 that displays the target color registration image data described above, displays target color candidates extracted according to the position designation by the user, and accepts selection by the user. A target color selection unit 903, a “decision” button 904 that is selected when the user's selection for the target color selection unit 903 is confirmed, an operation screen immediately before the selection is canceled (in this case, designation of image data for target color registration) A “cancel” button 905 used when returning to the screen. Although not particularly limited, here, the preview display unit 902 displays the thumbnail image obtained by reducing the number of pixels to the appropriate size for displaying the target color registration image data specified as described above. Here, the thumbnail image is generated by the target color extraction unit 406.

  On the target color position designation screen 901, the user uses his / her finger or touch pen 202 to designate the position where the target color desired to be registered exists on the target color registration image data displayed on the preview display unit 902. (Step S802 Yes). Here, it is assumed that the user designates a point 911 (a portion of the sunset sky in the image) shown in FIG. In response to the designation, the target color extraction unit 406 includes a point on the target color registration image data corresponding to the point 911 designated by the user in the thumbnail image displayed on the preview display unit 902 (or includes the point). The color information of the pixels existing in the (region) is extracted (step S803). The color information is a target color candidate. As described above, the color information may be a single color or a plurality of colors. Here, it is assumed that the target color extraction unit 406 extracts a plurality of target color candidates and specifies the target color candidates for three colors in descending order of the number of pixels from the plurality of target color candidates.

  The target color extraction unit 406 that has identified a plurality of target color candidates corresponding to the user's designated position displays the identified target color candidates on the target color selection unit 903 of the target color position designation screen 901, and the selection by the user is completed. (Steps S804 Yes, S805, S806 No). As illustrated in FIG. 9, the target color selection unit 903 includes rectangular images 912 to 914 colored with each target color candidate, and “registration” buttons 915 to 917 used to select target colors corresponding to the respective rectangular images. Is provided. This example shows a state in which the “Register” button 915 corresponding to the target color candidate 912 displayed on the left side in the target color selection unit 903 is selected.

  When the user selects the “OK” button 904 in this state, the target color extraction unit 406 inputs color information of the selected target color to the determination unit 409. In response to the input, the determination unit 409 determines whether or not the target color input from the target color extraction unit 406 belongs to a color range already registered in the target color holding unit 402 (steps S806 Yes and S807). As described above, in this example, the input target color is an existing color range registered in the target color holding unit 402 (here, “person photograph”, “landscape photograph (blue)”, “landscape photograph”). (Green) ”). Therefore, the determination unit 409 determines that the target color extracted by the target color extraction unit 406 does not belong to the existing color range (No in step S807). At this time, the determination unit 409 notifies the target color extraction unit 406 of the determination result.

  Upon receiving the notification, the target color extraction unit 406 inputs the color information of the extracted target color into the color range input unit 407. Receiving the input, the color range input unit 407 requests the user to input a color range associated with the input color information, and waits until the input is completed (No in steps S808 and S809).

  FIG. 10 is a diagram showing an example of a color range input screen displayed on the display 201 at this time. In this example, the color range input screen 1001 selects a color range in the lightness input column 1002, the saturation input column 1003, the hue angle input column 1004, and the color range selection screen 601 described above, which are used to input the color range. In the registered name input field 1005 used for inputting the name to be assigned to the button when selecting a color, in the target color selection screen displayed after selecting the color range, for inputting the name to be assigned to the button when selecting the target color A label name input field 1006 to be used, a “decision” button 1007 selected when the input to each input field is confirmed, and a “return” button used to cancel the selection and return to the target color position designation screen 901 1008.

  In the example of FIG. 10, the lower limit value “20” and the upper limit value “80” are set in the lightness input field 1002, and the lower limit value “70” and the upper limit value “120” are set in the saturation input field 1003. In the corner input field 1004, an example is shown in which a lower limit “−30 (330)” and an upper limit “40” are set. In the registered name input field 1005, “landscape photograph (red)” is set, and in the label name input field 1006, “red” is set. In the present embodiment, these setting values are input by the user using the operation keys 203 of the operation panel 200 or a software keyboard displayed on the display 201 as necessary. In the lightness input field 1002, the saturation input field 1003, and the hue angle input field 1004, for example, the upper and lower limit values are constant color differences centered on the target color input from the target color extraction unit 406 by the color range input unit 407, for example. The upper and lower limit values that fall within the range can be displayed as default values, and the default values can be finely adjusted by the user.

  When the input is confirmed by the user selecting the “OK” button 1007, the color range input unit 407 displays the input color range together with the color information of the target color input from the target color extraction unit 406 as a target color registration unit 408. (Step S809 Yes). The target color registration unit 408 that has received the input registers the color information of the input target color in the target color holding unit 402 in association with the input color range (step S810). Further, the target color registration unit 408 inputs the input color range to the pixel extraction unit 401 together with the input registration name and label name. Upon receiving the input, the pixel extraction unit 401 can select the input color range in the subsequent color correction.

  FIG. 11 shows a color range selection screen 601 displayed when a user selects a target color when performing color correction after a new target color is registered in the target color holding unit 402 as described above. FIG. In the above example, the user inputs the registered name “landscape photograph (red)” on the color range input screen 1001. Therefore, as shown in FIG. 11, the color range selection screen 601 after registration of the new target color has a “person photograph” button 602 corresponding to skin color and a “landscape photograph (blue)” button 603 corresponding to blue as selection buttons. In addition to a “landscape photo (green)” button 604 corresponding to green, a “landscape photo (red)” button 611 corresponding to red is provided.

  FIG. 12 is a diagram showing a target color selection screen displayed when the user selects the “landscape photo (red)” button 611 on the color range selection screen 601 shown in FIG. In the above example, the user inputs the label name “red” on the color range input screen 1001. Therefore, the target color selection screen 1201 corresponding to “landscape photograph (red)” is used to select a rectangular image 1202 colored with a newly registered target color and a target color corresponding to the rectangular image 1202. A “red 1” button 1203 and a “return” button 1204 used to cancel the selection and return to the color range selection screen 601 are provided. Therefore, the user can select a newly registered target color by selecting the “red 1” button 1203 on the target color selection screen 1201.

  On the other hand, in the above-described determination step (step S807), when the determination unit 409 determines that the target color extracted by the target color extraction unit 406 belongs to the existing color range (step S807 Yes), the determination unit 409 The determination result is notified to the target color extraction unit 406.

  Upon receiving the notification, the target color extraction unit 406 inquires of the user whether or not to register it as a target color belonging to the existing color range (step S811). At this time, the target color extraction unit 406 inquires of the user, for example, by displaying a button capable of selecting “register” or “not register” on the display 201. When the answer is input, the target color extraction unit 406 notifies the determination unit 409 of the answer.

  When the input answer is “register”, the determination unit 409 uses the color information of the target color input from the target color extraction unit 406 as the color already registered in the target color holding unit 402 to which the target color belongs. It inputs into the target color registration part 408 with the range (step S811 Yes). The target color registration unit 408 that has received the input registers the color information of the input target color in the target color holding unit 402 in association with the input color range (step S810). If the input answer is “not registered”, the determination unit 409 terminates the procedure without doing anything (step S811 No). Note that when the input answer is “not registered”, the user may register the target color to be registered in the target color holding unit 402 in association with the new color range. In this case, after the target color extraction unit 406 that has received an answer of “do not register”, the color range input unit 407 requests the user to input a color range (step S808).

  Although not particularly limited, in the present embodiment, when the target color candidate extracted by the target color extraction unit 406 in the target color candidate extraction step (step S804) according to the above-described user position designation is one color, The target color extracting unit 406 is configured to request the user to specify a color range without requesting the user to select a target color candidate (No in steps S804 and S807).

  As described above, in the multi-function device 100, the target color is registered using the image data itself, so that the user can register the color included in the image confirmed through vision as the target color. In addition, it is possible to set a color range to be subjected to color correction to a target color to be registered. Therefore, even a color such as a memory color that is not set in the image processing apparatus can register a user's favorite color as a target color. As a result, when color correction is performed, the user can easily perform color correction to a favorite color.

  Further, in the multifunction machine 100, when the target color registration image data includes a plurality of colors, the user can select a desired target color from the presented target color candidates. That is, the user's favorite color can be registered as a target color very easily and reliably.

  In addition, the MFP 100 is configured to register the registration target color in the target color holding unit 402 when the determination unit 409 determines that the registration target color does not belong to the existing color range. Thus, an approximate target color having a small color difference in the color space is not registered as a target color in a different color range. As a result, when performing color correction, it is possible to prevent a situation where it is difficult to select color correction because a number of approximate color ranges are presented to the user.

Note that the determination unit 409 replaces the target color input from the target color extraction unit 406 with the existing target color registered in the target color holding unit 402 in the determination step (step S807) instead of the above-described determination. On the other hand, it may be determined whether or not a color difference condition specified in advance is satisfied. Here, as the color difference condition, for example, a color difference in the CIE L ^* C ^* h color space between the target color already stored in the target color holding unit 402 and the target color to be registered is a predetermined value (for example, about 30 to 50). The above can be used. In this configuration, for example, when the color difference condition is satisfied, the same effect as described above can be obtained by registering a new target color and a new color range in the target color holding unit 402. Note that it is determined whether the target color input from the target color extraction unit 406 belongs to the existing color range registered in the target color holding unit 402, and the target color is registered in the target color holding unit 402. It is also possible to use a determination as to whether or not a predetermined color difference condition is satisfied for an existing target color.

  Further, in the above-described embodiment, as a particularly preferable form, a multifunction device including the determination unit 409 has been described. However, even when the determination unit 409 is not provided, the user includes at least an image confirmed through visual observation. Can be registered as a target color, and a color range to be subjected to color correction to the target color to be registered can be set.

  In this configuration, when the target color to be registered is selected in the target color selection step (step S806) shown in FIG. 8, the target color extraction unit 406 sends the color information of the selected target color to the color range input unit 407. input. Receiving the input, the color range input unit 407 requests the user to input a color range associated with the input color information, and waits until the input is completed (No in steps S808 and S809). When the input of the color range by the user is completed, the color range input unit 407 inputs the input color range to the target color registration unit 408 together with the color information of the target color input from the target color extraction unit 406 (Yes in step S809). . The target color registration unit 408 that has received the input registers the color information of the input target color in the target color holding unit 402 in association with the input color range (step S810). Further, the target color registration unit 408 inputs the input color range to the pixel extraction unit 401 together with the input registration name and label name.

  Each embodiment described above does not limit the technical scope of the present invention, and various modifications and applications can be made within the scope of the present invention other than those already described. For example, although the above embodiment has been described based on an operation through the operation panel of the multifunction device, an operation on the multifunction device may be performed via an information processing terminal that is communicably connected to the multifunction device. In this case, the function of the display 201 of the operation panel 200 in the above-described embodiment is provided by display means such as a display and input means such as a keyboard provided in the information processing terminal.

  Further, in the flowcharts shown in FIGS. 5 and 8, the order of the steps can be appropriately changed within a range where the equivalent action is achieved. For example, in FIG. 8, the color range input step (steps S808 and S809) by the user can be performed before designating image data or before designating a position on target color registration image data. In this case, the target color extraction unit 406 can extract only color information belonging to the input color range when extracting the target color candidates. In this way, it is possible to prevent color information that is inappropriate to be registered as a target color in the input color range from being extracted as a target color candidate. In addition, since the color information extracted as the target color candidate belongs to the input color range, a desired target color can be selected and registered from among a plurality of approximate target color candidates. Further, in such a configuration in which the color range is input in advance, the target color extraction unit 406 may automatically extract the target color candidates for the entire target color registration image data.

  Furthermore, in the above-described embodiment, instead of the rectangular image indicating the target color displayed on the target color selection screen, an image indicating the appearance of the image data after color correction may be used. In this case, as the displayed image data, either a thumbnail image of the correction target image data or an image different from the correction target data may be used. In this case, it is preferable to display an image showing the appearance of the image data before color correction on the target color selection screen. The image data after color correction is processed by the pixel extraction unit 401 and the color correction execution unit 404 according to the color range stored in the target color holding unit 402 and the target color with respect to the data before color correction. It can be generated by implementation.

  In addition, in the above-described embodiment, the present invention is embodied as a digital multi-function peripheral. However, the present invention can be applied not only to a digital multi-function peripheral but also to an arbitrary image processing apparatus such as a printer or a copier. .

  According to the present invention, a user can easily set desired color correction, which is useful as an image processing apparatus.

100 MFP (image processing device)
DESCRIPTION OF SYMBOLS 120 Image reading part 140 Image formation part 201 Display 401 Pixel extraction part 402 Target color holding | maintenance part 403 Target color selection reception part 404 Color correction implementation part 405 Registration image holding part 406 Target color extraction part 407 Color range input part 408 Target color registration 409 Determination unit 410 Correction target image holding unit 411 Image holding unit 1201 Selection image holding unit 1202 Image generation unit

Claims (4)

An image processing apparatus that performs color correction on image data,
A pixel extraction unit that extracts pixels belonging to a color range designated in advance from image data to be corrected;
A target color holding unit that stores a plurality of target colors in association with the previously specified color range;
A target color selection receiving unit that receives selection of one target color by the user from a plurality of target colors stored in the target color holding unit;
A color correction execution unit that performs color correction on the image data to be corrected based on the pixel color extracted by the pixel extraction unit and the target color selected through the target color selection receiving unit;
A registration image holding unit for holding image data including a target color to be registered;
A target color extraction unit that extracts the target color of the registration target from the image data held in the registration image holding unit;
A color range input unit for inputting a new color range to be associated with the target color to be registered extracted by the target color extraction unit;
A target color registration unit that registers the target color to be registered extracted by the target color extraction unit in the target color holding unit in association with the new color range input to the color range input unit;
An image processing apparatus comprising:   The target color extraction unit extracts pixels in an area of image data designated in advance, displays the color of the extracted pixels as registration target target color candidates, and accepts selection of a registration target target color by a user. The image processing apparatus according to claim 1. A determination unit for determining whether the target color to be registered extracted by the target color extraction unit belongs to a color range already registered in the target color holding unit;
When the determination unit determines that the color does not belong to the registered color range, the target color registration unit inputs the target color to be registered extracted by the target color extraction unit to the color range input unit The image processing apparatus according to claim 1, wherein the image processing apparatus is registered in the target color holding unit in association with the new color range. A determination unit for determining whether the target color to be registered extracted by the target color extraction unit satisfies a color difference condition specified in advance for the target color already registered in the target color holding unit;
When the determination unit determines that the color difference condition is satisfied, the target color registration unit inputs a new target color extracted by the target color extraction unit into the color range input unit. The image processing apparatus according to claim 1, wherein the image processing apparatus is registered in the target color holding unit in association with a color range.

Images