JP2013098617A - 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 the correction target image data 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 extraction 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 407 registers in the target color holding part 402 the target color to be registered extracted by the target color extraction part 406 in association with the color range specified in advance.

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 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 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 a color range designated in advance.

  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. Therefore, a user's favorite color such as a memory color can be registered as a target color very easily and reliably. As a result, when color correction is performed, the user can easily perform color correction to a favorite color. For example, color ranges corresponding to memory colors such as skin color, blue color, green color, and red color can be set as the color range.

  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. In this configuration, the target color extraction unit may extract only pixels belonging to a color range designated in advance.

In addition, the target color registration unit sets the target color to be registered when the target color to be registered satisfies the color difference condition specified in advance with respect to the target color already stored in the target color holding unit. The configuration may be registered in the holding unit. In this configuration, a similar color having a small color difference in the color space is not registered in the target color holding unit. As a result, when performing color correction, it is possible to prevent a situation where it is difficult to select a color correction because many similar colors are presented to the user. 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. .

  Further, the above-described image processing apparatus can include a selection image holding unit and an image generation unit. The selection image holding unit performs image correction when the color correction execution unit performs color correction on each of a plurality of target colors stored in the target color holding unit with respect to the pixels belonging to the color range specified in advance. A selection image displayed on the user when the target color is selected through the target color selection receiving unit is displayed. The image generation unit generates a selection image for the target color newly registered in the target color holding unit, and stores the selection image in the selection image holding unit.

  In this configuration, when the target color is selected, the appearance of the image data when color correction is performed on the same image data using different colors as the target color is displayed to the user. Therefore, even when a new target color is added, the color correction state can be visually recognized.

  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 designation | designated screen which the multifunctional device 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 Functional block diagram showing another multifunction machine according to an embodiment of the present invention. The figure which shows an example of the target color selection screen which the other multifunctional device in one Embodiment of this invention displays. The flowchart which shows an example of the image production | generation procedure for selection which the other multifunctional device in one Embodiment of this invention implements The figure which shows an example of the target color selection screen which the other 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 target color registration unit 407, and a correction target image holding unit 409. 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 409 use the color of pixels belonging to a predetermined color range as the target color in the multi-function device 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, and the target color registration unit 407 realize a function of registering a new target color in the target color holding unit 402 in the multifunction peripheral 100.

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 409. Here, the correction target image holding unit 409 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 409 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 409 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 409. 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, and the target color registration unit 407.

  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. Therefore, when a color range to be associated with a new target color is designated in advance, the target color extraction unit 406 selects a color belonging to the color range as a whole of the target color registration image data, target color registration image data. May be extracted from a position designated in advance for the target color or a position designated by the user for the target color registration image data. In this case, since a plurality of colors are usually extracted, one new target color may be determined as described above.

  The target color registration unit 407 registers the target color to be registered extracted by the target color extraction unit 406 in the target color holding unit 402 in association with the 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 409. 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 409. Note that if the same color correction is applied, the image data held in the correction target image holding unit 409 may be a plurality of pages, but here, description will be made 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 605 used to select a color range, and a “return” button 606 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 The example includes a “landscape photo (green)” button 604 corresponding to one green color and a “landscape photo (red)” button 605 corresponding to one of the memory colors red. When the user selects one button from the selection buttons 602 to 605, 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 605.

  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. Further, the “landscape photograph (red)” button 605 is associated with a target color adjusted in the direction of vivid red, a target color adjusted in the orange direction, and a target color adjusted in the pink direction. be able to.

  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. Upon receiving the notification, the pixel extraction unit 401 extracts pixels having colors belonging to the specified color range from the image data held in the correction target image holding unit 409. 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 409, 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 in which a target color is registered in “landscape photograph (blue)” will be described. 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 of an image showing the daytime sea is used as the target color registration image data. The image includes a blue sky, clouds, and the 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 blue sky portion 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 requests the user to specify a color range to be associated with the selected target color (No in steps S806 and S807). FIG. 10 is a diagram illustrating an example of a color range designation screen displayed on the display 201 at this time. In this example, the color range designation screen 1001 includes selection buttons 1002 to 1005 that are used to select a color range, and a “return” button 1006 that is used to cancel the selection and return to the target color position designation screen 901. . In FIG. 10, similarly to the color range selection screen 601 described above, as a selection button, a “portrait photograph” button 1002 corresponding to skin color, a “landscape photograph (blue)” button 1003 corresponding to blue, and a “landscape corresponding to green” A “photo (green)” button 1004 and a “landscape photo (red)” button 1005 corresponding to red are provided.

  When the user selects one of the selection buttons 1002 to 1005, the target color extraction unit 406 inputs the target color previously selected for the color range corresponding to the selected button to the target color registration unit 407. (Step S807 Yes). Receiving the input, the target color registration unit 407 registers the color information of the input target color in the target color holding unit 402 in association with the input color range (step S808). In the above example, since the user has extracted the blue sky color from the target color registration image data, the user selects the “landscape photograph (blue)” button 1003 on the color range designation screen 1001. As a result, the color information of the target color candidate selected by the user in the target color selection unit 903 of the target color position designation screen 901 is registered in the target color holding unit 402 in association with the blue color range.

  FIG. 11 shows a target color selection screen 701 that is displayed when the user selects a target color when performing color correction after the new target color is registered in the target color holding unit 402 as described above. FIG. As shown in FIG. 11, a rectangular image 711 colored with a new target color is added to the target color selection screen 701 as a fourth target color (hereinafter referred to as “blue 4”), and the rectangular image is also displayed. A “blue 4” button 712 used to select a target color corresponding to 711 is added. Therefore, the user can select the registered new target color “blue 4” in the subsequent color correction.

  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). When the target color candidate extracted by the target color extraction unit 406 in the extraction step (step S804) is one color, the target color registration unit 407 specifies the color range to which the target color candidate belongs, and the target color candidate Can be registered in the target color holding unit 402 in association with the specified color range.

  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. Therefore, a user's favorite color such as a memory color can be registered as a target color very easily and reliably. 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 the above description, the target color extraction unit 406 has described the configuration in which the color range is designated after the user has completed the selection of the target color candidate. However, the user can specify the color range before specifying the image data or before specifying the position on the target color registration image data. In this case, the target color extraction unit 406 more preferably extracts only color information belonging to the designated color range. With this configuration, it is possible to prevent color information that is inappropriate to be registered as a target color in the designated color range from being extracted as a target color candidate. Further, since the color information extracted as the target color candidate belongs to the specified color range, a desired target color can be selected and registered from a plurality of similar target color candidates. In such a configuration in which the color range is designated in advance, the target color extraction unit 406 may automatically extract the target color candidates for the entire target color registration image data. Alternatively, the target color extraction unit 406 can automatically extract target color candidates for a region designated in advance in association with a color range. The area designated in advance in association with the color range is, for example, an area that is detected as a human face in the target color registration image data if it is a skin color, and may be empty if it is blue or red. If it is green, it is the lower part of the target color registration image data that is likely to have lawn or grass. In this configuration, position designation by the user can be omitted.

In the MFP 100, the target color registration unit 407 satisfies the color difference condition in which the input target color to be registered is specified in advance with respect to the target color already stored in the target color holding unit 402. In this case, the registration target color may be registered in the target color holding unit 402. 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 3 to 10). The above can be used. In this configuration, a similar color having a small color difference in the color space is not registered in the target color holding unit 402. As a result, when performing color correction, it is possible to prevent a situation where it is difficult to select color correction because a large number of colors similar to the target color selection screen 701 are presented to the user. In this configuration, the target color registration unit 407 notifies the target color extraction unit 406 that the input target color to be registered does not satisfy the color difference condition specified in advance. Upon receiving the notification, the target color extraction unit 406 notifies the user by displaying a message such as “A color very similar to the designated target color has already been registered” on the display 201. As a result, the user can know that a target color similar to the selected target color has already been registered, and registration as a new target color is unnecessary.

  By the way, in the above example, when performing color correction, the user has described a configuration in which the target color is selected on the target color selection screen 701 while referring to a rectangular image colored with each target color. However, in reproducing a memory color, it is required to reproduce an image of a color existing in human memory. Therefore, in the configuration in which the target color is selected only with the rectangular image colored with the target color, it may be difficult to determine whether or not the image data after color correction that is close to the selected target color matches the user's image. Conceivable. Therefore, hereinafter, a configuration in which the user can select a target color based on the comparison between the image data before color correction and the image data after color correction will be described.

  FIG. 12 is a functional block diagram showing another multifunction machine according to the present embodiment. As illustrated in FIG. 12, the other multifunction device 1200 includes a selection image holding unit 1201 and an image generation unit 1202 in addition to the configuration of the multifunction device 100 described above. In FIG. 12, elements having the same functions and effects as those of the MFP 100 shown in FIG. Hereinafter, differences from the multifunction peripheral 100 will be described in detail.

  The selection image holding unit 1201 holds a selection image for each of a plurality of target colors stored in the target color holding unit 402 in association with the designated color range. Here, the image for selection is image data indicating the appearance of each image data when the color correction execution unit 404 performs color correction according to each target color for pixels belonging to the specified color range. The image generation unit 1202 generates a selection image for the target color newly registered in the target color holding unit 402 by the target color registration unit 407 and stores the selection image in the selection image holding unit 1201.

  In this example, the selection image holding unit 1201 holds a sample image as a selection image. That is, the selection image holding unit 1201 shows a specific image corresponding to the color range and an appearance when the color correction execution unit 404 performs color correction corresponding to the target color on the specific image. Images are stored. For example, as described above, when three target colors are registered for one color range, the pre-correction image and the pre-correction image are displayed for each of the three target colors in the selection image holding unit 1201. Four images of the three corrected images subjected to color correction by the correction execution unit 404 are stored. In this example, an image corresponding to each color range is stored as the pre-correction image. That is, the selection image holding unit 1201 displays an image in which skin such as a person's face occupies many areas in the image as a selection image corresponding to the skin color (“person photograph”), blue (“landscape photograph (blue)” )) As a selection image corresponding to a blue sky or the like occupying many areas in the image, and as a selection image corresponding to green ("landscape photo (green)") vegetation or the like occupies many areas in the image. As an image for selection corresponding to an image, red (“landscape photograph (red)”), an image in which a sunset sky or the like occupies many areas in the image is stored.

  In the multifunction device 1200, the selection image is displayed to the user when the target color is selected through the target color selection receiving unit 403. That is, in the above-described target color selection screen 701, the selection image is displayed instead of the rectangular images 702 to 704. The display on the target color selection screen 701 is performed when the target color selection receiving unit 403 reads a selection image corresponding to the target color from the selection image holding unit 1201.

  FIG. 13 is a diagram illustrating an example of a target color selection screen 701 displayed on the display 201 by the target color selection receiving unit 403 in the multifunction device 1200. Here, a target color selection screen 701 displayed when the user selects “landscape photograph (green)” on the color range selection screen 601 is shown. In this example, the target color selection screen 701 includes images 1302 to 1304 indicating the appearance when color correction is performed on a specific image as selection images. In FIG. 13, the image 1302 corresponds to the first target color (hereinafter referred to as “green 1”), the selection image 1303 corresponds to the second target color (hereinafter referred to as “green 2”), and The selection image 1304 corresponds to the third target color (hereinafter referred to as “green 3”). The target color selection screen 701 includes a “green 1” button 1305, a “green 2” button 1306, and a “green 3” button 1307 used for selecting a target color corresponding to each selection image. The target color selection screen 701 is configured to display the above-mentioned pre-correction image that has not been subjected to color correction corresponding to each target color as the original image 1301 together with the selection images 1302 to 1304. In FIG. 13, a tree image is used as the selection image. Also, the trees in each selection image are not monochromatic, but include both colors that belong to the color range of “landscape photograph (green)” and colors that do not belong to the color range.

  In the present embodiment, the selection image holding unit 1201 stores the above-described selection image in association with the color information of the corresponding target color. Therefore, the target color selection receiving unit 403 can notify the color correction execution unit 404 of the color information of the target color in accordance with the target color selection by the user in the target color selection receiving unit 403.

  FIG. 14 is a flowchart illustrating an example of a selection image generation procedure performed by the MFP 1200. This procedure is started before a new target color is registered in the target color holding unit 402 by the target color registration unit 407 in the target color registration procedure shown in FIG. The process proceeds with the color registered in the target color holding unit 402 as a trigger (step S1401 Yes).

  The target color registration unit 407 that has registered a new target color in the target color holding unit 402 notifies the image generation unit 1202 to that effect. Upon receiving the notification, the image generation unit 1202 starts generating a selection image corresponding to the newly registered target color (step S1402).

  First, the image generation unit 1202 acquires the color information of the newly registered target color and the color range associated with the target color from the target color holding unit 402. In addition, the image generation unit 1202 acquires a pre-correction image corresponding to the acquired color range from the selection image holding unit 1201. The image generation unit 1202 that has acquired the pre-correction image inputs the acquired pre-correction image and color information of the newly registered target color to the color correction execution unit 404, and also acquires the acquired pre-correction image and the registered target color. The color range associated with is input to the pixel extraction unit 401. Then, the image generation unit 1202 waits until the color correction in the color correction execution unit 404 is completed (No in step S1403).

  In response to the input, the pixel extraction unit 401 and the color correction execution unit 404 extract pixels belonging to the color range input from the pre-correction image by the above-described method, and perform the above-described color correction on the pixel. . As a result, a selection image corresponding to the newly registered target color is generated. The color correction execution unit 404 inputs the generated selection image to the image generation unit 1202. Receiving the input, the image generation unit 1202 stores the input selection image in the selection image holding unit 1201 in association with the color range and the target color (step S1404).

  FIG. 15 is displayed when the user selects a target color when performing color correction after the selection image corresponding to the new target color is registered in the selection image holding unit 1201 as described above. It is a figure which shows the target color selection screen. As shown in FIG. 15, the target color selection screen 701 includes a selection image 1311 that shows the appearance when the original image 1301 is subjected to color correction according to a new target color, as a fourth target color (hereinafter referred to as “target color”). , “Green 4”.) And a “green 4” button 1312 used to select a target color corresponding to the selection image 1311 is added. Accordingly, in the subsequent color correction, the user can select the registered new target color “green 4” while referring to the selection image.

  In the above description, the selection image holding unit 1201 is configured to hold a selection image (sample image) based on an image different from the correction target image data. However, the selection image stored in the selection image holding unit 1201 is used. May be an image showing an appearance when color correction corresponding to each target color is performed on the correction target image data, such as a thumbnail image of the correction target image data. In this case, each time the correction target image data is selected, the image forming unit 1202 displays the selection image corresponding to the correction target image data in the color information and color range of the target color stored in the target color holding unit 903. It will generate based on.

  As described above, in the multi-function device 1200, when the target color is selected, the appearance of the image data when color correction is performed on the same image data using different colors as the target color is displayed to the user. Therefore, even when a new target color is added, the user can visually recognize the state of color correction, and the user's favorite color can be registered as the target color very easily and reliably. The selection is easy as well.

  The above-described embodiments do not limit the technical scope of the present invention, and various modifications and applications other than those already described are possible within the scope of the present invention. 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, 8, and 14, the order of the steps can be appropriately changed within a range in which equivalent actions are achieved.

  Furthermore, in the above-described embodiment, the present invention is embodied as a digital multifunction peripheral. However, the present invention is not limited to a digital multifunction peripheral, and can be applied to an arbitrary image processing apparatus such as a printer or a copying machine.

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

100, 1200 MFP (image processing device)
120 Image Reading Unit 140 Image Forming Unit 201 Display 401 Pixel Extraction Unit 402 Target Color Holding Unit 403 Target Color Selection Accepting Unit 404 Color Correction Performing Unit 405 Registration Image Holding Unit 406 Target Color Extracting Unit 407 Target Color Registration Unit 409 Correction Target Image Holding unit 411 Image holding unit 1201 Selection image holding unit 1202 Image generation unit

Claims (5)

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 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 previously specified color range;
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.   The image processing apparatus according to claim 2, wherein the target color extraction unit extracts only pixels belonging to the color range specified in advance.   The target color registration unit sets the registration target target color to the target color holding unit when the registration target target color satisfies a color difference condition designated in advance with respect to the target color already stored in the target color holding unit. The image processing apparatus according to any one of claims 1 to 3, wherein the image processing apparatus is registered. An appearance of each image data when the color correction execution unit performs color correction on each of a plurality of target colors stored in the target color holding unit with respect to pixels belonging to the predetermined color range. And a selection image holding unit that holds a selection image displayed to the user at the time of target color selection through the target color selection receiving unit,
An image generation unit that generates the selection image for the target color newly registered in the target color holding unit and stores the selection image in the selection image holding unit;
The image processing apparatus according to claim 1, further comprising:

Images