JP2011091753A - Imaging apparatus, image processing apparatus, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration for obtaining an image subjected to other different color reproduction operations from a color-adjusted image obtained through a color adjusting operation not via a RAW image. <P>SOLUTION: An imaging apparatus includes an imager for capturing an image of a subject, an image processor, a memory for storing color conversion information therein, and an image file generator. The image processor subjects an image captured by the imager to color reproduction operation to generate a color-reproduced image. The color conversion information in the memory indicates a conversion format between apparatus-independent first color information on reference color and apparatus-independent second color information for use in the color reproduction operation of the image processor. The image file generator generates an image file while making the color-reproduced image correspond to the color conversion information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Recent electronic cameras have shooting scene modes such as a landscape mode and a portrait mode, and a user can arbitrarily set a mode optimal for shooting a specific scene. In accordance with the mode selection, setting of shooting conditions suitable for each mode and image quality adjustment are automatically executed. In the image quality adjustment, the hue and saturation of the captured image are adjusted depending on each mode. Such a technique is disclosed in Patent Document 1 and Patent Document 2, for example.

JP 2003-283882 A JP 2002-344989 A

  By the way, although it is possible to obtain a color adjustment image corresponding to various modes from a RAW image, an image subjected to another different color adjustment process is obtained from a color adjustment image obtained by a predetermined color adjustment process. Is currently difficult.

  SUMMARY OF THE INVENTION An object of the present invention is to provide means for obtaining an image subjected to another color reproduction process without passing through a RAW image from a color adjustment image obtained by the color adjustment process.

  An imaging apparatus according to one aspect includes an imaging unit that captures an image of a subject, an image processing unit, a storage unit that stores color conversion information, and an image file generation unit. The image processing unit performs color reproduction processing on the image captured by the imaging unit to generate a color reproduction image. The color conversion information in the storage unit indicates a conversion mode between the device-independent first color information with respect to the reference color and the device-independent second color information applied in the color reproduction process in the image processing unit. . The image file generation unit generates an image file by associating the color reproduction image with the color conversion information.

  The imaging apparatus according to the one aspect may further include a mode selection unit that selects a mode to be executed by the image processing unit from a plurality of modes corresponding to different color adjustments according to a shooting situation. The storage unit may store a plurality of pieces of color conversion information corresponding to a plurality of modes, respectively. The image file generation unit may generate an image file by associating the color conversion information corresponding to the mode selected by the mode selection unit with the color reproduction image. Note that the image file generation unit may further record color conversion information corresponding to another mode not selected by the mode selection unit in association with the color reproduction image.

  In the one aspect described above, the color conversion information may be a color conversion matrix or a color conversion table. Further, the color conversion information may further include information on gradation conversion characteristics reflecting the display characteristics of the image on the display device.

  An image processing apparatus according to another aspect uses an acquisition unit that acquires a color reproduction image and color conversion information generated by the imaging apparatus according to one aspect, and the color reproduction image as a reference color using the color conversion information. An image generation unit that converts the color into a device-independent color.

  A color management system or color that combines a program that causes a computer to operate as an image processing apparatus according to another aspect described above, a storage medium that stores the program, an imaging apparatus according to one aspect, and an image processing apparatus according to another aspect. A management method or the like is also effective as a specific aspect of the present invention.

  According to the present invention, it is possible to obtain a color reproduction image subjected to another different color adjustment process without passing through a RAW image from a color reproduction image subjected to a specific color adjustment process.

The block diagram which shows the structural example of the color management system in one Embodiment Flow chart showing an example of conversion information generation procedure 6 is a flowchart showing an operation example of the electronic camera in one embodiment. 6 is a flowchart illustrating an example of the operation of a computer according to an embodiment.

<Description of One Embodiment>
FIG. 1 is a block diagram illustrating a configuration example of a color management system according to an embodiment. The color management system of one embodiment has an electronic camera 1 as an imaging device and a computer 2 as an image processing device.

  First, a configuration example of the electronic camera 1 in one embodiment will be described. The electronic camera 1 includes an imaging optical system 11, an imaging device 12, a DFE 13, an image processing engine 14, a first memory 15 and a second memory 16, a media I / F 17, a communication I / F 18, and a monitor 19. And an operation unit 20 that receives user operations. Here, the DFE 13, the first memory 15 and the second memory 16, the media I / F 17, the communication I / F 18, the monitor 19, and the operation unit 20 are each connected to the image processing engine 14.

  The image pickup device 12 is a device that picks up an image of an object formed by a light beam that has passed through the image pickup optical system 11. The output of the image sensor 12 is connected to the DFE 13. The image sensor 12 of one embodiment may be a progressive scanning solid-state image sensor (CCD or the like) or an XY address type solid-state image sensor (CMOS or the like).

  A plurality of light receiving elements are arranged in a matrix on the light receiving surface of the imaging element 12. Further, a color filter is disposed in each light receiving element of the image pickup element 12 and is not particularly limited, but in this embodiment, red (R), green (G), and blue (B) color filters are known Bayer. Arranged according to the sequence. Therefore, each light receiving element of the imaging element 12 outputs an image signal corresponding to each color by color separation in the color filter. Thereby, the image sensor 12 can acquire a color image at the time of imaging.

  The DFE 13 is a digital front-end circuit that performs signal processing such as A / D conversion of image signals input from the image sensor 12 and correction of defective pixels. The DFE 13 outputs RAW image data to the image processing engine 14. Here, the RAW image is a digital image in which the relationship between the output signal value and the amount of incident light is linear. This RAW image may have been subjected to defective pixel correction processing. Further, the RAW image may be a mosaic image having a Bayer arrangement structure in a state before color interpolation, or may be a color image after color interpolation processing has been performed.

  The image processing engine 14 is a processor that comprehensively controls each unit of the electronic camera 1. For example, the image processing engine 14 executes a known autofocus (AF) control based on contrast detection or a known automatic exposure (AE) calculation based on the output of the image sensor 12. The image processing engine 14 operates as an image processing unit 21, a mode selection unit 22, a recording control unit 23, and an image file generation unit 24 by executing the program.

  The image processing unit 21 performs color reproduction processing on the RAW image data to generate color reproduction image data corresponding to a photograph. Note that the color reproduction image data is generated in a known format such as the JPEG format or the TIFF format.

  Here, the color reproduction processing is processing for realizing color reproduction intended by the user, and includes, for example, gradation conversion processing, white balance adjustment, and color conversion processing. In the above color reproduction processing, by correcting the hue and saturation, for example, an image region having a color close to a color (skin color, sky color, leaf green color, etc.) that a human has a specific fixed concept is used. Close to the memory color corresponding to the fixed concept.

  Further, the electronic camera 1 has a plurality of color reproduction modes corresponding to the situation that the user intends to shoot, such as a portrait mode and a landscape mode. In each color reproduction mode, the image processing unit 21 executes different color reproduction processes on the RAW image.

  The mode selection unit 22 selects a color reproduction mode to be executed by the image processing unit 21 from a plurality of color reproduction modes. Then, the image processing unit 21 performs color reproduction processing on the captured RAW image based on the color reproduction mode selected by the mode selection unit 22.

  Here, the mode selection unit 22 may select a color reproduction mode according to a user's specification. Alternatively, the mode selection unit 22 may execute a known scene analysis process using the captured image and automatically select a color reproduction mode corresponding to the scene according to the analysis result (auto mode).

  The image file generation unit 24 generates an image file of a color reproduction image based on a predetermined file format (for example, TIFF / EP standard, Exif standard, etc.). The recording control unit 23 performs control to record the image file generated by the image file generation unit 24 in a storage medium 17a described later.

  The first memory 15 is a volatile buffer memory that temporarily stores image data before and after image processing.

  The second memory 16 is a non-volatile flash memory that stores various programs executed by the image processing engine 14. The second memory 16 stores a plurality of pieces of conversion information corresponding to the respective color reproduction modes. The conversion information includes device-independent color information (color correction information) acquired using a standard chart in which reference colors are arranged, and device-independent color information of an image obtained by the color reproduction process. The relationship with (color adjustment information) is shown.

  As an example, the above conversion information includes the tristimulus values (XYZ values) obtained by measuring a standard chart with a measuring instrument under a predetermined light source, and the color obtained by imaging the same chart with the electronic camera 1 under the same light source. The conversion mode with the tristimulus values (XYZ values) in the reproduced image is shown. The tristimulus values (XYZ values) of the color reproduction image obtained by imaging the standard chart are different for each color reproduction mode and each light source. Therefore, the content of the conversion information changes according to the combination of the color reproduction mode and the light source, and the electronic camera 1 has a plurality of conversion information for each color reproduction mode.

  Further, the above conversion format is constituted by, for example, a 3 × 3 color conversion matrix. By using such a conversion mode, it is possible to perform color conversion that minimizes the color difference of the same color patch between the color information related to the standard chart measured by the measuring instrument and the color information related to the color reproduction image. In this way, device-independent color correction information and color adjustment information are acquired. In the example of the embodiment, since the conversion information is a 3 × 3 color conversion matrix, the conversion information is configured with nine parameters for one color reproduction mode.

  Hereinafter, an example of the conversion information generation procedure will be described with reference to the flowchart of FIG. Note that the generation of the conversion information is generally performed by the manufacturer of the imaging device. 2 is recorded in the second memory 16 in the manufacturing process of the electronic camera 1 or the like.

  Step S101: First, a standard chart such as a color checker DC of Greta Macbeth is prepared. Then, under the CIE standard light source D65, each color patch of the standard chart is measured (colorimetric) with a measuring instrument to obtain tristimulus values (XYZ values). As a result, tristimulus values as colorimetric values that serve as a reference for color information are acquired for each color patch.

  Step S102: The above standard chart is imaged in all color reproduction modes of the electronic camera 1 under the CIE standard light source D65. Thereby, the color reproduction image of the standard chart corresponding to each color reproduction mode is acquired. Note that the color space of the color reproduction image in S102 is set to RGB.

  Step S103: Using the color reproduction image obtained in S102, tristimulus values (XYZ values) of each color patch in all color reproduction modes are obtained.

  As an example, in S103, an average value of RGB is obtained in each color patch region for one color reproduction image, and RGB values corresponding to the number of color patches in the image are obtained. Then, the above RGB values are converted into XYZ values, respectively. By performing the above processing on all color reproduction images, the tristimulus values of each color patch in each color reproduction mode are acquired.

  Here, the output of a JPEG image captured by a general electronic camera is optimized in the sRGB standard color space unless otherwise specified. Therefore, the conversion from RGB to XYZ in S103 is usually performed based on sRGB. When the output of the electronic camera is optimized to the AdobeRGB color space, the conversion from RGB to XYZ in S103 may be performed based on AdobeRGB.

  Step S104: Using the tristimulus values measured in S101 and the tristimulus values in the color reproduction image obtained in S103, a color conversion matrix corresponding to each color reproduction mode is obtained.

As an example, the tristimulus value in the reference color image is “X _m Y _m Z _m ”, the tristimulus value in S102 is “X _j Y _j Z _j ”, and the obtained 3 × 3 color conversion matrix is “M "

の式において、Ｘ_ｍＹ_ｍＺ_ｍとＸ_ｊＹ_ｊＺ_ｊとが近い値をとるように、色変換マトリクスＭを最小二乗法などで最適化すればよい。上記の処理をすべての色再現モードで行うことにより、各々の色再現モードにおける色変換マトリクスＭがそれぞれ取得される。 At this time,

In this equation, the color conversion matrix M may be optimized by the least square method or the like so that X _m Y _m Z _m and X _j Y _j Z _j take close values. By performing the above processing in all color reproduction modes, the color conversion matrix M in each color reproduction mode is acquired.

  If sRGB (white point D65) is assumed in the optimization of the JPEG image, the white points do not match under a light source other than D65. Therefore, when obtaining the tristimulus value by the color reproduction image of the electronic camera 1 under a light source other than D65, the gradation value of the image acquired under the other light source is temporarily converted to the value of the D65 light source, May be performed.

  Returning to FIG. 1, a non-volatile storage medium 17 a can be detachably connected to the media I / F 17. Then, the media I / F 17 executes data writing / reading with respect to the storage medium 17a. The storage medium 17a is composed of a hard disk, a memory card incorporating a semiconductor memory, or the like. In FIG. 1, a memory card is illustrated as an example of the storage medium 17a.

  The communication I / F 18 controls data transmission / reception with an external apparatus (such as an image processing apparatus) connected via a known wired or wireless communication line in accordance with a predetermined communication standard. The monitor 19 displays a captured image or the like under the control of the image processing engine 14.

  Next, the configuration of the computer 2 in one embodiment will be described. The computer 2 is a personal computer in which an image processing program is installed. The computer 2 includes a data reading unit 31, a communication unit 32, a storage device 33, a CPU 34, a memory 35, an input / output I / F 36, and a bus 37. Have. The data reading unit 31, the communication unit 32, the storage device 33, the CPU 34, the memory 35, and the input / output I / F 36 are connected to each other via a bus 37. Furthermore, an input device 38 (a keyboard, a pointing device, etc.) and a monitor 39 are connected to the image processing apparatus 2 via an input / output I / F 36. The input / output I / F 36 accepts various inputs from the input device 38 and outputs display data to the monitor 39.

  The data reading unit 31 is used when reading image file data generated by the electronic camera 1 and an image processing program from the outside. For example, the data reading unit 31 includes a reading device (such as a reading device for an optical disk, a magnetic disk, a magneto-optical disk, or a memory card) that acquires data from a removable storage medium.

  The communication unit 32 controls data transmission / reception with an external device (such as the electronic camera 1) connected via a known wired or wireless communication line in accordance with a predetermined communication standard.

  The storage device 33 stores the image processing program and various data necessary for executing the program. The storage device 33 can also store image file data acquired from the data reading unit 31 or the communication unit 32. The storage device 33 is configured by a hard disk, a nonvolatile semiconductor memory, or the like.

  The CPU 34 is a processor that comprehensively controls the operation of each unit of the image processing apparatus 2. The CPU 34 also functions as an image generation unit that converts the color reproduction image into a device-independent color with respect to the reference color by executing the image processing program. An example of the operation of the image processing program by the image processing apparatus will be described later. The memory 35 temporarily stores the calculation result of the image processing program. The memory 35 is composed of, for example, a volatile SDRAM.

  Next, operation examples of the electronic camera 1 and the computer 2 in one embodiment will be described. First, an operation example of the electronic camera 1 in one embodiment will be described with reference to the flowchart of FIG.

  Step S201: As preparation before imaging, the mode selection unit 22 sets a color reproduction mode (landscape mode, portrait mode, auto mode, etc.) at the time of imaging according to a user operation.

  As an example, when the user designates the landscape mode, the mode selection unit 22 sets the color reproduction mode to the landscape mode. As a result, the image processing unit 21 performs color reproduction processing in the landscape mode during imaging. When the color reproduction mode is set to the auto mode, a known scene analysis process is executed using the image captured by the image processing engine 14, and the color reproduction mode corresponding to the scene to be captured is set according to the analysis result. The mode selection unit 22 automatically sets.

  Step S202: The image processing engine 14 drives the image sensor 12 according to a user's imaging instruction, and executes imaging of an image accompanied by recording in the storage medium 17a.

  The output of the imaging device 12 passes through the DFE 13 in a pipeline manner and is input to the image processing engine 14. Then, the image processing unit 21 performs color reproduction processing in the color reproduction mode (here, landscape mode) set in S201 on the RAW image data, and acquires color reproduction image data. Note that the color reproduction image data is temporarily stored in the first memory 15.

  Step S203: The image file generation unit 24 performs color reproduction by associating the header data including the shooting condition information (shutter time, aperture value, imaging sensitivity, etc.) and conversion information with the color reproduction image data (S202). Generate an image file for the image. Thereafter, the recording control unit 23 records the image file of the color reproduction image on the storage medium 17a.

  Here, the header data is generated by the image file generation unit 24. Further, the image file generation unit 24 includes conversion information corresponding to the color reproduction process (color reproduction mode) in S202 in the header data. For example, since the landscape mode is designated by the user here, the file generation unit 24 includes conversion information corresponding to the landscape mode in the header data. Thus, by applying the above conversion information to the color reproduction image data, the color reproduction image of the image file is converted into an image in a state corresponding to the colorimetric values of the scene (scene-referred image), that is, color correction information. Based on this, it is possible to convert the image to a color-corrected image.

  Further, the image file generation unit 24 may further include conversion information corresponding to another color reproduction mode (in this case, for example, portrait mode) not selected by the mode selection unit 22 in the header data. Note that the conversion information of other color reproduction modes is applied when the above-described image-referred image is converted into a color reproduction state in another color reproduction mode (see Modification 2 described later). Above, description of the operation example of the electronic camera 1 is complete | finished.

  Next, an exemplary operation of the computer 2 in one embodiment will be described with reference to the flowchart of FIG. As an example, FIG. 4 illustrates a case where a color reproduction image that has been subjected to color reproduction processing in the landscape mode by the electronic camera 1 is converted into a scene-referred image in relation to FIG. 4 is started when the CPU 34 executes the image processing program in response to a program execution instruction from the user.

  Step S301: The CPU 34 acquires an image file of the color reproduction image (generated in S203) from the electronic camera 1. The transfer of the image file between the electronic camera 1 and the computer 2 is realized by exchanging the storage medium 17 a from the data reading unit 31 or data communication via the communication unit 32. Further, the image file acquired in S301 is recorded in the storage device 33 or the memory 35 under the control of the CPU 34.

Step S302: The CPU 34 converts the reproduction color of each pixel in the color reproduction image of the image file from an RGB value to a tristimulus value (XYZ value). The RGB value of the reproduction color in the landscape mode is expressed as “RGB _(f) ”, and the XYZ value of the reproduction color in the landscape mode is expressed as “XYZ _(f) ”.

If the output of the electronic camera that generated the image file is optimized for sRGB, the conversion from RGB _(f) to XYZ _(f) in S302 is performed based on sRGB. When the output of the electronic camera is optimized in the AdobeRGB color space, the above conversion may be performed based on AdobeRGB.

  Step S303: The CPU 34 obtains conversion information corresponding to the color reproduction process (landscape mode) in S202 from the header data of the image file.

Step S304: The CPU 34 uses the color conversion matrix of the conversion information acquired in S303 to change the color of each pixel (XYZ _(f) ) in the color reproduction image to the color of the captured scene (XYZ value of scene color: XYZ). _(S) Each is converted into ₍₎ .

Step S305: The CPU 34 further converts the XYZ value (XYZ _(s) ) converted in S304 into an RGB value (RGB _(s) ) of the scene color. Note that the conversion from XYZ _(s) to RGB _(s) in S305 is performed based on sRGB (or AdobeRGB) as in S302.

Step S306: The CPU 34 causes the monitor 39 to display and output the image (RGB _(s) ) after the processing of S305. The CPU 34 may record the image data after the conversion in S305 in the storage device 33. Above, description of the operation example of FIG. 4 is complete | finished.

  As described above, the subject is reproduced with a color different from the measured color of the scene in the color reproduction image so that the image looks good for the user. However, there are cases where a person is included in the subject even in shooting in landscape mode, and because the landscape is included in shooting in portrait mode, the boundary of the color reproduction mode is ambiguous. Further, it is difficult to completely satisfy the user for any scene by correcting the hue and saturation by the color reproduction process.

  Therefore, when the color reproduction image of the image file is viewed on the computer 2, for an image in which the color reproduction intended by the user is not performed in terms of hue and saturation, there is no color adjustment by color reproduction processing. It may be preferable to convert the image once to a referred image.

  The computer 2 according to the embodiment uses the conversion information previously added to the image file of the color reproduction image, thereby smoothly converting the color of the color reproduction image into the colorimetric value of the scene without using the RAW image. be able to.

<Modification 1 of one embodiment>
The color management system of one embodiment can also be applied to conversion of the color reproduction state across models of electronic cameras. As an example, an example will be described in which a color reproduction image acquired in the landscape mode of the electronic camera A is converted into a color reproduction state of the electronic camera B in the landscape mode. In this case, the CPU 34 of the computer 2 may perform the following processes (A1)-(A3). In the description of Modification 1, in addition to the conversion information corresponding to the landscape mode of the electronic camera A, conversion information corresponding to the landscape mode of the electronic camera B is generated in advance, and the conversion information is stored in advance in the storage device 33. Or on the memory 35.

(A1) The CPU 34 converts the RGB value (RGB _(fA) ) of the color reproduction image acquired in the landscape mode of the electronic camera A into an XYZ value (XYZ _(fA) ). Then, using the conversion information (color conversion matrix) corresponding to the landscape mode of the electronic camera A, the CPU 34 converts the above XYZ _(fA) into the color of the scene (XYZ _(s) ). The processes (A1) may be performed in the same manner as S301 to S304 in FIG.

(A2) The CPU 34 reads the conversion information corresponding to the recorded landscape mode of the electronic camera B, and changes the color (XYZ _(s) ) of the captured scene to the XYZ value of the reproduced color in the landscape mode of the electronic camera B. Applies to conversion to (XYZ _(fB) ). Note that the CPU 34 may perform the conversion in (A2) using the conversion information acquired from the header of the image file.

(A3) The CPU 34 converts the XYZ value (XYZ _(fB) ) of the reproduced color in the landscape mode of the electronic camera B into an RGB value (RGB _(fB) ) by the same processing as S305 in FIG.

  In general, if the models of electronic cameras are different, even if the same subject is imaged in the color reproduction mode with the same name, the reproduced color will be different. Therefore, when the reproduction color in the color reproduction mode of a certain electronic camera is preferable, the user may want to use the color reproduction characteristics in the preferable color reproduction mode even in another electronic camera model.

  In addition, when editing publications, etc., there may be a case where it is desired to suppress variations in the reproduced color of an image group shot using a plurality of electronic camera models. For example, when a color reproduction image with insufficient saturation and a color reproduction image with enhanced saturation coexist on the same page of a publication, it is difficult to cope with color adjustment by solid density in the printing process.

  The computer 2 according to the first modification can smoothly convert the color of the landscape mode of the electronic camera A into the colorimetric value of the scene and then smoothly convert it to the color of the landscape mode of the electronic camera B.

<Modification 2 of one embodiment>
The color management system of one embodiment can also be applied to conversion to a color reproduction state in a different color reproduction mode. As an example, an example will be described in which a color reproduction image acquired in the landscape mode of the electronic camera A is converted into a color reproduction state of the portrait mode of the electronic camera A. In this case, the CPU 34 of the computer 2 may perform the following processes (B1)-(B3).

(B1) The CPU 34 converts the RGB value (RGB _(fA) ) of the color reproduction image acquired in the landscape mode of the electronic camera A into an XYZ value (XYZ _(fA) ). Then, using the conversion information (color conversion matrix) corresponding to the landscape mode of the electronic camera A, the CPU 34 converts the above XYZ _(fA) into the color of the scene (XYZ _(s) ). The processes (B1) described above may be performed in the same manner as S301 to S304 in FIG.

(B2) The CPU 34 uses the conversion information corresponding to the portrait mode of the electronic camera A to change the color (XYZ _(s) ) of the captured scene to the XYZ value (XYZ value) of the reproduced color in the portrait mode of the electronic camera A. _(PA) ). Note that conversion information corresponding to the portrait mode of the electronic camera A may be added to the header of the image file, or may be stored in advance in the storage device 33 or the memory 35. The CPU 34 reads the conversion information corresponding to the portrait mode and performs the conversion in (B2).

(B3) The CPU 34 converts the XYZ value (XYZ _(pA) ) of the reproduced color in the portrait mode of the electronic camera A into an RGB value (RGB _(pA) ) by the same processing as S305 in FIG.

  For example, when the color reproduction mode of the electronic camera is set in the above-described auto mode, a color reproduction mode that is generally highly relevant is selected, but a color reproduction mode that is not suitable for the scene to be imaged is rarely selected. It can happen. The computer 2 according to the second modification converts the color of the landscape mode of the electronic camera A into a colorimetric value of the scene, and then smoothly converts the color of the electronic camera A to another color reproduction mode (for example, portrait mode). Can be converted to

<Supplementary items of the embodiment>
(1) The image processing apparatus of the present invention is not limited to the example of the personal computer of the above embodiment. For example, the electronic camera 1 may function as the image processing apparatus of the present invention. Further, although an electronic camera has been described as an example of an imaging apparatus, the present invention is not limited to this. For example, an imaging apparatus that acquires an image of a subject such as a digital video camera or a mobile phone with a camera may be used.

  (2) In the above embodiment, an example in which the image processing engine 14 implements each process of the image processing unit 21, the mode selection unit 22, the recording control unit 23, and the image file generation unit 24 of the electronic camera 1 by software. As described above, it goes without saying that each of these processes may be realized by hardware using an ASIC.

(3) In the above embodiment, the example in which the 3 × 3 color conversion matrix is applied as the conversion information has been described. However, the conversion information may be configured by a multidimensional color conversion lookup table (LUT). For example, in the L ^* a ^* B ^* color space, the conversion information can also be constituted by a three-dimensional color conversion LUT that performs conversion between the reproduction color of the color reproduction mode and the colorimetric value of the scene.

  (4) Generally, in color reproduction images, gradation conversion is often performed to optimize display on a display device. In this case, in order to convert a color reproduction image into a scene-referred image, it is necessary to consider the gradation conversion described above. Therefore, the conversion information of the above embodiment may further include gradation conversion characteristic information that reflects the display characteristics of the image on the display device. For example, when the luminance of the color reproduction image on the display device and the luminance of the scene have a non-linear relationship, a gradation conversion parameter (gamma) for correcting the luminance of the color reproduction image and the luminance of the scene to have linearity. A curve or the like) may be included in the conversion information.

  (5) In the above embodiment, the example in which the conversion information is generated in association with the actual colorimetric value in the measuring instrument and the reproduction color in the electronic camera 1 has been described. However, the conversion information of the present invention may be generated by simulation. For example, assuming a light source in a known standard subject spectral database and using a color matching function, a colorimetric value of a scene can be obtained by calculation. In addition, assuming a light source in a known standard subject spectral database, a reproduction color in a color reproduction image can be obtained by calculation from a spectral sensitivity model of the image sensor 12 and image processing parameters. And if the calculation of S104 is performed based on both data, conversion information can be obtained by calculation.

  From the above detailed description, features and advantages of the embodiments will become apparent. It is intended that the scope of the claims extend to the features and advantages of the embodiments described above without departing from the spirit and scope of the right. Further, any person having ordinary knowledge in the technical field should be able to easily come up with any improvements and modifications, and there is no intention to limit the scope of the embodiments having the inventive features to those described above. It is also possible to use appropriate improvements and equivalents within the scope disclosed in.

DESCRIPTION OF SYMBOLS 1 ... Electronic camera, 2 ... Computer, 12 ... Image sensor, 14 ... Image processing engine, 15 ... 1st memory, 16 ... 2nd memory, 17 ... Media I / F, 17a ... Storage medium, 21 ... Image processing part, DESCRIPTION OF SYMBOLS 22 ... Mode selection part, 23 ... Recording control part, 24 ... Image file generation part, 31 ... Data reading part, 33 ... Memory | storage device, 34 ... CPU

Claims (7)

An imaging unit that captures an image of a subject;
An image processing unit that performs color reproduction processing on an image captured by the imaging unit to generate a color reproduction image;
Stores color conversion information indicating a conversion mode between device-independent first color information with respect to a reference color and device-independent second color information applied in the color reproduction process in the image processing unit. A storage unit;
An image file generation unit that generates an image file by associating the color reproduction image and the color conversion information;
An imaging apparatus comprising: The imaging device according to claim 1,
A plurality of modes each corresponding to a different color adjustment, further comprising a mode selection unit that selects the mode to be executed by the image processing unit according to the shooting situation;
The storage unit stores a plurality of the color conversion information respectively corresponding to a plurality of the modes,
The image file generating unit generates an image file by associating the color conversion information corresponding to the mode selected by the mode selection unit with the color reproduction image. The imaging device according to claim 2,
The image file generation unit is an imaging apparatus that records the color conversion information corresponding to another mode not selected by the mode selection unit in association with the color reproduction image. In the imaging device according to any one of claims 1 to 3,
The image conversion apparatus, wherein the color conversion information is a color conversion matrix or a color conversion table. The imaging apparatus according to claim 4,
The image conversion apparatus, wherein the color conversion information further includes gradation conversion characteristic information reflecting display characteristics of an image on a display apparatus. An acquisition unit that acquires the color reproduction image and the color conversion information generated by the imaging device according to claim 1;
Using the color conversion information, an image generation unit that converts the color reproduction image into a device-independent color with respect to a reference color;
An image processing apparatus comprising: A program that causes a computer to operate as the image processing apparatus according to claim 6.

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