JP2015015681A - Imaging device, control method therefor, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide image data having desired characteristics irrespective of a system of color correction processing in an imaging device.SOLUTION: A digital camera 100 performs color correction processing on captured image data. Then, the digital camera 100 generates an image processing parameter to be used for image processing of the image data subjected to the color correction processing in accordance with a system of the color correction processing.

Description

  The present invention relates to a technique for generating image processing parameters used for image processing of image data subjected to color correction processing.

  Conventionally, in a lens used for photographing with a camera, there may be a difference in color characteristics between lens types due to spectral characteristics of an optical system, characteristics of a coating material, and the like. When shooting moving image data such as in a digital cinema, the color characteristics of each lens have been utilized in making works as the taste of the lens. On the other hand, there are users who want to take a picture while canceling the color characteristics of the lens. For example, when compositing image data shot using lenses with different color characteristics, the images are shot with the influence of the color characteristics of each lens canceled, and the difference in color gradation characteristics between the image data It is desirable to eliminate

  In moving image data shooting in digital cinema or the like, generally, after shooting, color grading processing that corrects the captured moving image data to a desired appearance is performed. The correction parameters in this color grading process are recorded and used in a format called ASC-CDL. ASC-CDL (hereinafter referred to as CDL) is a format created and recommended by the ASC (American Society of Cinematographers) Technical Committee.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for recording a CDL correction parameter and performing color grading processing on image data at the time of photographing based on the correction parameter. Patent Document 2 discloses a technique in which correction parameters suitable for a lens are recorded in the lens, and when the lens is mounted on a camera, the correction parameter is read and color correction processing is performed.

JP 2009-77765 A JP 2003-78794 A

  By the way, there are a case where the user wants to take a picture taking advantage of the color characteristic of the attached lens and a case that he wants to take a picture while canceling the color characteristic of the lens. However, in the prior art, color correction processing related to the color characteristics of the lens cannot be appropriately switched and executed according to these demands. This is because when performing color correction processing related to lens color characteristics, it is necessary to determine color correction parameters in consideration of not only the color characteristics of the lens but also the state of color signal processing such as white balance correction in the camera. Because there is.

  Therefore, an object of the present invention is to obtain image data having desired characteristics regardless of the color correction processing method in the imaging apparatus.

  The imaging apparatus according to the present invention includes: an imaging unit; a color correction unit that performs color correction processing on image data captured by the imaging unit; and the color correction according to a color correction processing method performed by the color correction unit. Generating means for generating image processing parameters used for image processing of the image data subjected to color correction processing by the means.

  According to the present invention, it is possible to obtain image data having desired characteristics regardless of the color correction processing method in the imaging apparatus.

It is a figure which shows the structure of the imaging | photography system which concerns on embodiment of this invention. It is a figure which shows the detailed structure of a camera. It is a figure which shows the structure of the image process part of a camera. It is a flowchart which shows the imaging | photography process in the 1st and 3rd embodiment of this invention. It is a figure which shows the example of the color characteristic information for every lens recorded on a non-volatile memory. 6 is a flowchart showing color correction parameter generation processing executed in step S103 of FIG. It is a flowchart which shows the imaging | photography process in the 2nd Embodiment of this invention. It is a flowchart which shows the detail of the production | generation process of the color correction parameter performed in step S303 of FIG. It is a flowchart which shows the detail of the production | generation process of the color correction parameter of step S103 of FIG. 4 in the 3rd Embodiment of this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments to which the invention is applied will be described in detail with reference to the accompanying drawings.

  First, a first embodiment of the present invention will be described. The first embodiment of the present invention corrects the color characteristics of an interchangeable lens (hereinafter abbreviated as “lens”) attached to a camera based on color characteristic information of a lens specified by a user at the time of shooting. The color correction parameter is generated. The color correction parameter is an example of an image processing parameter.

  FIG. 1 is a diagram showing a configuration of an imaging system according to the first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a digital camera (hereinafter abbreviated as a camera). Reference numeral 200 denotes a color grading apparatus that performs color grading processing on image data captured by the camera 100. Reference numeral 201 denotes a monitor that displays image data that has undergone color grading processing.

  Next, an outline of the operation of the photographing system according to the present embodiment will be described. The camera 100 captures a subject and records the captured image data on a recording medium in association with color correction parameters of a color decision list (CDL) that is color correction information generated in the camera 100. The color grading apparatus 200 reads image data captured by the camera 100 and color correction parameters recorded in association with the image data from a recording medium. The color grading apparatus 200 performs color correction processing on the image data read from the recording medium based on the color correction parameters recorded in association with the image data. The color grading apparatus 200 can also perform color grading processing on the image data in accordance with an instruction from the user. The color grading apparatus 200 outputs the image data subjected to the color grading process to the monitor 201.

  Next, the configuration of the camera 100 will be described in detail with reference to FIG. In FIG. 2, 100 is a camera and 101 is a lens. The lens 101 has an interface unit (not shown) that communicates with the system control unit 50 of the camera 100, and can communicate ID information and the like of the lens 101. Reference numeral 102 denotes a shutter having an aperture function. Reference numeral 103 denotes an image pickup unit composed of a CCD, a CMOS element, or the like that converts an optical image into an electric signal. Reference numeral 104 denotes an A / D converter that converts an input analog signal into a digital signal. An image processing unit 105 performs various types of image processing such as white balance processing, γ processing, and color correction processing on the digital signal image data output from the A / D converter 104. Reference numeral 106 denotes an image memory. Reference numeral 107 denotes a memory control unit that controls the image memory 106. A D / A converter 108 converts an input digital signal into an analog signal. Reference numeral 109 denotes a display such as an LCD. A codec unit 110 compresses and encodes image data.

  Reference numeral 111 denotes a recording I / F, which is an interface with the recording medium 112. Reference numeral 112 denotes a recording medium such as a memory card or a hard disk. Reference numeral 113 denotes an external output I / F that controls output to the monitor 201. Reference numeral 50 denotes a system control unit that controls the entire system of the camera 100. An operation unit 120 is used to input various operation instructions. Reference numeral 121 denotes a power switch. 122 is a power supply unit. Reference numeral 123 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM. A system timer 124 measures the time used for various controls and the time of a built-in clock. A system memory 125 expands constants and variables for operation of the system control unit 50, programs read from the nonvolatile memory 123, and the like. A communication unit 126 performs wireless communication with an external device.

  Next, a basic processing flow at the time of subject shooting by the camera 100 will be described. The imaging unit 103 photoelectrically converts light incident through the lens 101 and the shutter 102 and outputs the converted light to the A / D converter 104 as an analog signal. The A / D converter 104 converts the analog signal input from the imaging unit 103 into a digital signal, and outputs the digital signal to the image processing unit 105 as image data.

  The image processing unit 105 performs color conversion processing such as white balance correction processing and γ processing on the image data input from the A / D converter 104 or the image data read out from the memory control unit 107. The image processing unit 105 performs predetermined calculation processing using the captured image data, and the system control unit 50 performs exposure control and distance measurement control based on the obtained calculation result. As a result, TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and the like are performed.

  The image data output from the image processing unit 105 is written into the image memory 106 via the memory control unit 107. The image memory 106 stores image data output from the imaging unit 103 and image data to be displayed on the display unit 109. The D / A converter 108 converts display image data stored in the image memory 106 into an analog signal and supplies the analog signal to the display unit 109. The display unit 109 performs display according to the analog signal input from the D / A converter 108 on a display device such as an LCD. The external output I / F 113 outputs the image data stored in the image memory 106 to an external monitor (not shown).

  The codec unit 110 compresses and encodes the image data recorded in the image memory 106 based on a standard such as MPEG. The system control unit 50 stores the encoded image data or uncompressed image data in the recording medium 112 via the recording I / F 111.

  In addition to the basic operation described above, the system control unit 50 implements each process of the present embodiment described later by executing a program recorded in the nonvolatile memory 123. The program here is a program for executing the contents of various flowcharts described later in the present embodiment. At this time, the system control unit 50 develops operation constants, variables, a program read from the nonvolatile memory 123, and the like in the system memory 125.

  FIG. 3 is a diagram illustrating a configuration of the image processing unit 105 of the camera 100. As shown in FIG. 3, the image processing unit 105 includes a color signal generation unit 1051, a WB (white balance) amplification unit 1052, a color correction unit 1053, a gamma processing unit 1054, and a luminance / color difference signal generation unit 1055.

  Next, processing in the image processing unit 105 will be described. The image processing unit 105 inputs image data from the A / D converter 104 in FIG. The image data input to the image processing unit 105 is a RAW format Bayer RGB signal, and the Bayer RGB signal is input to the color signal generation unit 1051. The color signal generation unit 1051 performs a synchronization process on the input Bayer RGB signal to generate an RGB color signal. The color signal generation unit 1051 outputs the generated RGB color signal to the WB amplification unit 1052.

  The WB amplification unit 1052 adjusts the white balance by applying a gain to the RGB color signal based on the white balance gain value calculated by the system control unit 50. Here, it is assumed that one of the following methods is used as a method of calculating the white balance gain value. The first method is called a white set method, in which an achromatic chart is photographed with a camera, and a white balance gain value is determined so that the photographed chart portion is achromatic. In other words, this is a method of color correction processing (first color correction processing) in which a correction value is obtained based on image data picked up with a lens mounted, and the direction of canceling the color characteristics of the lens mounted at this time The correction value is calculated. The second method is called a preset method, which reads and uses a preset white balance gain value. In other words, this is a method of color correction processing (second color correction processing) based on a predetermined correction value, and a correction value that does not depend on the color characteristics of the lens mounted at this time is calculated. In the preset method, a white balance gain value suitable for each color temperature is set in advance as the white balance gain value, and is recorded in the nonvolatile memory 123. Therefore, the user can select the white balance gain value according to the color temperature of the illumination light source at the time of shooting. In the white set method, the white balance is generally determined including the influence of the color characteristics of the mounted lens 101, and the captured image data is affected by the color characteristics of the lens 101. Absent. On the other hand, in the preset method, the white balance is generally determined without considering the color characteristics of the mounted lens 101, and the captured image data is affected by the color characteristics of the lens 101.

  The color correction unit 1053 corrects the color tone by performing 3 × 3 matrix processing or three-dimensional LUT (Look Up Table) processing on the RGB color signals. The gamma processing unit 1054 is connected to the Rec. Gamma correction such as multiplication by gamma in accordance with a standard such as 709 or log format gamma is performed. The luminance / color difference signal generation unit 1055 generates a luminance signal Y, color difference signals RY, and BY signals from the RGB color signals. The luminance / color difference signal generation unit 1055 outputs the generated luminance signal Y and color difference signals RY and BY signals to the recording I / F 111.

  Returning to the description of FIG. The recording I / F 111 outputs the input image data to the recording medium 112. The recording I / F 111 outputs the color correction parameter generated by the system control unit 50 to the recording medium 112 in association with the image data.

Here, the color correction parameters generated by the system control unit 50 will be described. The color correction process using the correction parameter can be expressed as follows, assuming that the signal before correction is In and the signal after correction is Out.
Out = (slope × In + offset) ^power
Note that “slope”, “offset”, and “power” are color correction parameters, and are values given for each of the RGB color signals.

  Next, imaging processing in the first embodiment will be described with reference to FIG. First, the user attaches the lens 101 used for photographing to the camera 100. Next, the user uses the operation unit 120 of the camera 100 to perform an operation of setting a lens color characteristic correction mode, which is a mode for generating a color correction parameter, to ON. Thereby, in step S101, the system control unit 50 sets the lens color characteristic correction mode to ON. Then, the user uses the operation unit 120 of the camera 100 to perform an operation of designating the target lens color characteristic information. Thereby, the system control unit 50 sets the color characteristic information of the target lens.

  The color correction parameter generated by the system control unit 50 is a parameter for correcting the color characteristic of the captured image data so as to be the color characteristic indicated by the target lens color characteristic information. The color characteristic information of the lens may be expressed in any format, but in this embodiment, two values of slope (R) and slope (B) that are values of slope for the R and B signals are represented by the color of the lens. It shall be used as characteristic information. In the nonvolatile memory 123, color characteristic information (slope (R), slope (B)) is recorded in association with typical lens types.

  FIG. 5 is a diagram illustrating an example of color characteristic information for each lens recorded in the nonvolatile memory 123. Although the lens type is represented by the lens ID in FIG. 5, when the user specifies the color characteristic information of the target lens, a name representing the lens type converted from the lens ID is presented to the user. May be. The user designates color characteristic information of the target lens by selecting the target lens by looking at the name indicating the lens type displayed on the display unit 109.

  Next, the user uses the operation unit 120 of the camera 100 to perform an operation for performing white balance correction processing. At this time, the user selects one of the white set method and the preset method as the white balance correction method. Thereby, in step S102, the system control unit 50 sets one of a white set method and a preset method as the white balance correction method.

  Next, the system control unit 50 calculates a white balance gain value by the white balance correction method selected by the user. The calculated white balance gain value is set in the WB amplifying unit 1052 of the image processing unit 105, and is used when white balance correction processing is performed on image data captured by the camera 100. Further, in addition to the white balance correction process, the user performs various setting processes by operating the lens aperture, focus, and the like so as to be in a state suitable for shooting.

  Next, the user uses the operation unit 120 of the camera 100 to perform an operation for capturing image data. Thereby, in step S103, the system control unit 50 starts photographing processing. At this time, after performing the color correction parameter generation processing, the system control unit 50 issues an instruction to each unit of the image processing unit 105 to start capturing image data.

  Next, the color correction parameter generation process executed in step S103 will be described in detail with reference to FIG.

  In step S201, the system control unit 50 determines whether the lens color characteristic correction mode is set to ON. If the lens color characteristic correction mode is set to ON, the process proceeds to step S202. On the other hand, when the lens color characteristic correction mode is not set to ON (when set to OFF), the system control unit 50 ends the process without generating a color correction parameter.

  In step S202, the system control unit 50 acquires the target lens color characteristic information designated by the user from the lens color characteristic information table shown in FIG. In step S <b> 203, the system control unit 50 acquires color characteristic information of the lens 101 attached to the camera 100. Specifically, the system control unit 50 reads the lens ID from the lens 101, and acquires color characteristic information corresponding to the lens ID from the lens color characteristic information table shown in FIG.

  In step S <b> 204, the system control unit 50 calculates the difference between the target lens color characteristic information and the lens 101 color characteristic information. In step S205, the system control unit 50 determines whether or not the calculated difference in color characteristic information is equal to or greater than a predetermined threshold value. If the difference in color characteristic information is greater than or equal to the predetermined threshold, the process proceeds to step S206. On the other hand, when the difference in the color characteristic information is less than the predetermined threshold, the system control unit 50 ends the process without generating a color correction parameter.

  In step S206, the system control unit 50 acquires the white balance correction method set in step S102 of FIG. In step S207, the system control unit 50 determines whether the acquired white balance correction method is a white set method or a preset method. In the case of the white set method, the process proceeds to step S208. On the other hand, in the case of the preset method, the process proceeds to step S209.

  In step S208, the system control unit 50 generates a color correction parameter indicating the color characteristic information of the target lens. That is, since the color setting of the lens 101 is canceled due to the setting of the white setting method, the system control unit 50 corrects the image data with the color characteristic information of the target lens. The color correction parameter of is generated.

In step S209, the system control unit 50 cancels the color characteristics of the lens 101 to be mounted, and then generates a color correction parameter for correcting the image data with the color characteristic information of the target lens. Specifically, slope_mounting (R) and slope_mounting (B) which are color characteristic information of the lens 101 to be mounted, and slope_target (R) and slope_target (B) which are color characteristic information of the target lens Are used to generate color correction parameters as follows.
Slope (R) = slope_target (R) / slope_mounted (R)
Slope (B) = slope_target (B) / slope_mounted (B)
That is, since the preset method is set, the color characteristic of the lens 101 to be mounted is reflected in the image data, and after canceling the influence of the color characteristic, the target lens color characteristic information is used. Correction is performed.

  In step S210, the system control unit 50 controls to output the color correction parameter generated in step S208 or step S209 to the recording medium 112 via the recording I / F 111 and record it in association with the image data. . Then, when performing the color grading process, the color grading apparatus 200 reads the color correction parameters generated by the series of processes described above from the recording medium, and applies them to the image data associated with the color correction parameters. It is possible to correct the image data so that the color characteristic indicated by the color characteristic information of the target lens is obtained.

  In the present embodiment, the color correction parameter generation method is changed depending on whether the white balance correction method is the white set method or the preset method. Thereby, it is possible to obtain image data having desired color characteristics regardless of the white balance correction method.

  In the above-described embodiment, the case where the color correction parameter and the color characteristic information of the lens 101 are represented by CDL has been described. However, the present invention can represent any color correction parameter or color characteristic information of the lens 101 as long as the color correction parameter and the color characteristic information of the lens 101 can be represented. Format information may be used. For example, an LUT (Look Up Table) may be used as the color correction parameter. Further, the color characteristic information of the lens 101 may be expressed in the form of color information in a specific color space. As a result, it is possible to realize fine correction processing that cannot be expressed by CDL.

  In the present embodiment, the case where the image data is corrected based on the color characteristic of the lens has been described. However, the present invention can perform any correction process as long as the correction process is based on the lens characteristic information. Good. For example, information indicating lens transmittance may be acquired, and a process for correcting a difference in brightness of image data due to a difference in lens transmittance may be performed.

  In this embodiment, the color correction parameter is generated immediately before the image data is recorded. However, in the present invention, the timing for generating the color correction parameter is not limited to this. For example, the color correction parameter may be calculated every time the white balance correction method is changed. Further, when generating the color correction parameter, it may be determined whether the currently set white balance correction method is set with the current lens attached.

  In the present embodiment, the case has been described in which target color characteristic information of a lens is specified from candidates recorded in advance. However, in the present invention, the method of specifying color characteristic information of a lens is not limited to this. For example, the user may input desired color characteristic information by operating the operation unit 120 of the camera 100.

In this embodiment, the white set correction method and the preset method are exemplified as the white balance correction method. However, the present invention can also be applied to other white balance correction methods. For example, in the case of an Auto white balance correction method that estimates the current color temperature of a light source from an image signal of a photographed image, the white balance correction method is set based on the image signal affected by the color characteristics of the lens. Is done. For this reason, after the white balance correction method is set, the color characteristics of the lens are canceled. Therefore, color correction parameters may be generated as in the white set method.

  In this embodiment, the color correction parameter generation processing is controlled based on the white balance correction method. However, not only the setting of the white balance correction method but also the setting state of the color correction processing executed before and after that is read. The color correction parameter may be generated based on the setting state of the color correction process. For example, when the process of increasing the saturation of the image signal is performed in the camera 100 as the color correction process, the influence of the color characteristics of the lens on the image data also increases. For this reason, after canceling the color characteristics of the mounted lens, control is performed to increase the correction amount of the color correction parameter for correcting the image data with the color characteristic information of the target lens. Further, control is performed so as to increase the correction amount of the color correction parameter for correcting the color correction parameter with the target lens color characteristic information. Thereby, even when color correction processing is performed in the camera 100, the color characteristics of the image data can be corrected to the color characteristics photographed by the target lens.

  Next, a second embodiment of the present invention will be described. In the first embodiment, a case has been described in which color correction parameters for correcting captured image data with target lens color characteristic information are generated. On the other hand, in the second embodiment, a case will be described in which whether or not to cancel the color characteristics of a mounted lens is set at the time of shooting, and color correction parameters suitable for the setting are generated. In addition, since the structure of the imaging | photography system which concerns on 2nd Embodiment, a camera, and an image process part is the same as that of the structure shown in FIGS. 1-3, these codes shall be used also in the following description. .

  First, the photographing process in the second embodiment will be described with reference to FIG. Note that step S302 in FIG. 7 is the same as step S102 in FIG. 4, and thus description thereof is omitted here.

  The user uses the operation unit 120 of the camera 100 to perform an operation of setting a lens color characteristic correction mode, which is a mode for generating color correction parameters, to ON. Thereby, in step S301, the system control unit 50 sets the lens color characteristic correction mode to ON. Furthermore, the user uses the operation unit 120 of the camera 100 to perform an operation of selecting whether to cancel the color characteristics of the lens 101 or not. Thereby, the system control unit 50 sets whether or not to cancel the color characteristics of the lens 101.

  In step S303, the system control unit 50 starts shooting processing. At this time, after performing the color correction parameter generation processing, the system control unit 50 issues an instruction to each unit of the image processing unit 105 to start capturing image data. Here, the color correction parameter generation process executed in step S303 of FIG. 7 will be described in detail with reference to FIG.

  In step S401, the system control unit 50 determines whether or not the lens color characteristic correction mode is set to ON. If the lens color characteristic correction mode is set to ON, the process proceeds to step S402. On the other hand, when the lens color characteristic correction mode is not set to ON (when set to OFF), the system control unit 50 ends the process without generating a color correction parameter.

  In step S <b> 402, the system control unit 50 acquires color characteristic information of the lens 101 attached to the camera 100. Specifically, the system control unit 50 reads the lens ID from the lens 101, and acquires color characteristic information corresponding to the lens ID from the lens color characteristic information table shown in FIG.

  In step S403, the system control unit 50 determines whether or not the setting for canceling the color characteristics of the lens has been performed in step S301. If the setting is made to cancel the color characteristics of the lens, the process proceeds to step S404. On the other hand, if the setting is made so as not to cancel the color characteristic of the lens, that is, the setting that leaves the influence of the color characteristic of the lens is made, the process proceeds to step S407.

  In step S404, the system control unit 50 determines whether the white balance correction method set in step S302 of FIG. 7 is the white set method (or the Auto method) or the preset method. If it is the white set method (or the Auto method), the process proceeds to step S405. On the other hand, in the case of the preset method, the process proceeds to step S406.

  In step S405, the system control unit 50 generates a color correction parameter for through setting. Specifically, slope (R) = slope (B) = 1 is set. This is because the influence of the color characteristics of the lens 101 is removed by the white balance correction processing of the white set method, and therefore image data with a desired image quality can be obtained without performing color correction.

In step S406, the system control unit 50 generates a color correction parameter for removing the color characteristics of the lens 101. Specifically, the color correction parameter is generated as follows.
Slope (R) = 1 / slope_Installation (R)
Slope (B) = 1 / slope_mounting (B)
This is because the influence of the color characteristics of the lens 101 is not canceled out in the preset type white balance correction processing. Therefore, in order to obtain image data having a desired color characteristic, the color characteristic of the image data is changed using the color correction parameter. This is because it is necessary to correct.

  In step S407, as in step S404, the system control unit 50 determines whether the white balance setting method set in step S302 in FIG. 7 is the white set method or the preset method. In the case of the white set method, the process proceeds to step S408. On the other hand, in the case of the preset method, the process proceeds to step S409.

In step S <b> 408, the system control unit 50 generates a color correction parameter for reflecting the color characteristics of the mounted lens 101 in the image data. Specifically, the color correction parameter is generated as follows. This is because the influence of the color characteristics of the lens 101 is removed by the white balance correction processing of the white set method, and it is necessary to reflect the color characteristics of the mounted lens 101 in the image data.
Slope (R) = slope_ wearing (R)
Slope (B) = slope_ wearing (B)

  In step S409, the system control unit 50 sets a color correction parameter for through setting. Specifically, slope (R) = slope (B) = 1 is set. This is because in the preset type white balance correction process, the influence of the color characteristics of the lens 101 is not canceled out, so that image data having a desired color characteristic can be obtained without performing color correction. In step S410, the system control unit 50 controls the color correction parameter generated in any of steps S405, S406, S408, and S409 to be output to the recording I / F 111 and recorded in association with the image data. To do. In step S411, the system control unit 50 ends the process without generating a color correction parameter.

  The color grading apparatus 200 reads the color correction parameter generated by the above-described series of processes from the recording medium, and applies the correction to the image data associated with the color correction parameter to perform correction. As described above, in the present embodiment, it is possible to correct image data by selecting whether to cancel the influence of the color characteristics of the lens or not.

  In the present embodiment, the color correction parameter value depends on whether the influence of the color characteristic of the mounted lens 101 is canceled or not, and whether the white balance correction method is the white set method or the preset method. The generation process was controlled. As a result, it is possible to correct image data having desired color characteristics regardless of the white balance correction method.

  In the above-described embodiment, a case has been described in which color correction parameters for through setting in which no correction is performed when it is not necessary to perform color correction of image data. However, the present invention is not limited to this. . For example, when it is not necessary to perform color correction of image data, no color correction parameter is generated, or a color correction parameter is generated, but the color correction parameter may not be recorded in association with image data. .

  Next, a third embodiment of the present invention will be described. In the second embodiment, a case has been described in which whether or not to cancel the color characteristics of a mounted lens is set at the time of shooting and a color correction parameter suitable for the setting is generated. On the other hand, in the third embodiment, two types of color correction parameters, that is, the case where the influence of the color characteristic of the mounted lens 101 is removed and the case where it is not removed are generated, and these are used in the color grading process after photographing. One of the color correction parameters can be selected. In addition, since the structure of the imaging | photography system which concerns on 3rd Embodiment, a camera, and an image process part is the same as that of the structure shown in FIGS. 1-3, these codes shall be used also in the following description. .

  The shooting process in the third embodiment of the present invention is the same as the shooting process in the first embodiment shown in FIG. 4 except for the color correction parameter generation process in step S103. Therefore, hereinafter, the color correction parameter generation processing in step S103 in the third embodiment will be described. FIG. 9 is a flowchart showing details of the color correction parameter generation processing in step S103 of FIG. 4 in the third embodiment.

  In step S <b> 501, the system control unit 50 acquires color characteristic information of the lens 101 attached to the camera 100. Specifically, the system control unit 50 reads the lens ID from the lens 101, and acquires color characteristic information corresponding to the lens ID from the lens color characteristic information table shown in FIG.

  In step S502, the system control unit 50 determines whether the white balance setting method set in step S102 of FIG. 4 is the white set method (or the Auto method) or the preset method. If it is the white set method (or the Auto method), the process proceeds to step S503. On the other hand, in the case of the preset method, the process proceeds to step S505.

  Hereinafter, in the third embodiment, two types of color correction parameters (CDL1) corresponding to the case where the color characteristics of the lens 101 are canceled and color correction parameters (CDL2) corresponding to the case where the color characteristics of the lens 101 are not canceled are used. Color correction parameters are generated, and both are recorded in association with image data.

  In step S503, the system control unit 50 generates a color correction parameter for through setting, and sets the value as CDL1. Specifically, CDL1 is set as slope (R) = slope (B) = 1. In step S504, the system control unit 50 generates a color correction parameter for reflecting the color characteristics of the mounted lens 101 in the image data, and sets the value as CDL2. Specifically, CDL2 is set as Slope (R) = slope_mounting (R) and Slope (B) = slope_mounting (B).

  In step S505, the system control unit 50 generates a color correction parameter that cancels the color characteristics of the mounted lens 101, and sets the value as CDL1. Specifically, CDL1 is set as Slope (R) = 1 / slope_mounting (R) and Slope (B) = 1 / slope_mounting (B). In step S806, the system control unit 50 generates a color correction parameter for through setting, and sets the value as CDL2. Specifically, slope (R) = slope (B) = 1 is set.

  In step S507, the system control unit 50 outputs the two types of color correction parameters generated in steps S503 and S504 or steps S505 and S506 to the recording I / F 111, and associates both of them with image data. Control to record.

  After shooting, the user uses the color grading apparatus 200 to read out the image data and the color correction parameters recorded in association with the image data, and correct the image data. At this time, when the user wants to remove the influence of the color characteristic of the lens on the image data, the user selects CDL1, and when he wants to use the image data while keeping the influence of the color characteristic of the lens, the user selects CDL2. The color grading apparatus 200 can obtain image data with a desired image quality by applying the selected color correction parameter to the image data.

  As described above, in the present embodiment, depending on whether the white balance correction method is the white set method or the preset method, the effect of the color characteristics of the mounted lens 101 is removed and the case where it is not removed. The method of generating the two types of color correction parameters was changed. As a result, it is possible to correct image data having desired color characteristics regardless of the white balance correction method.

  In the above-described embodiment, the case where two types of color correction parameters, that is, the case where the influence of the color characteristic of the mounted lens 101 is removed and the case where it is not removed is described. However, the present invention is not limited to this. . For example, when the influence of the color characteristic of the mounted lens 101 is removed by the white balance correction method of the white set method, only the color correction parameter (CDL2) corresponding to the case where the color characteristic of the lens 101 is not canceled is generated. To do. On the other hand, when the influence of the color characteristic of the lens 101 is not removed by the preset white balance correction method, only the color correction parameter (CDL1) corresponding to the case where the color characteristic of the lens 101 is canceled is generated. Good. When the image data read into the color grading apparatus 200 does not have color characteristics, the user can obtain image data having desired color characteristics by applying color correction parameters associated with the image data to the image data. It becomes possible.

  In the above-described embodiment, the method for generating the color correction parameter has been described. However, the present invention can also be applied to the case of generating the gradation correction parameter for correcting the gradation of the image data.

  The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

  100: Digital camera, 200: Color grating device, 201: Monitor, 50: System control unit, 112: Recording medium, 1052: WB amplification unit

Claims (18)

Imaging means;
Color correction means for performing color correction processing on image data picked up by the image pickup means;
Generating means for generating image processing parameters used for image processing of the image data subjected to color correction processing by the color correction means in accordance with a color correction processing method by the color correction means. An imaging device.   The generation unit generates an image processing parameter based on characteristic information of a lens attached to the imaging unit or a characteristic of a lens attached to the imaging unit according to a color correction processing method by the color correction unit. The imaging apparatus according to claim 1, wherein the imaging apparatus controls whether to generate an image processing parameter that is not based on information.   When the white balance correction processing by the color correction unit is a white set method or an Auto method, the generation unit generates an image processing parameter that is not based on characteristic information of a lens attached to the imaging unit, and the color correction unit The imaging apparatus according to claim 2, wherein when the white balance correction processing by the is a preset method, an image processing parameter is generated based on characteristic information of a lens attached to the imaging unit.   The generation unit generates an image processing parameter based on target lens characteristic information when generating an image processing parameter not based on characteristic information of a lens attached to the imaging unit. The imaging apparatus according to 2 or 3. Setting means for setting whether or not to cancel the characteristics of the lens mounted on the imaging means;
The imaging apparatus according to claim 1, wherein the generation unit generates an image processing parameter in accordance with a setting content by the setting unit and a color correction processing method by the color correction unit.   The generating unit generates an image processing parameter based on characteristic information of a lens attached to the imaging unit according to a setting content by the setting unit and a color correction processing method by the color correcting unit, or 6. The image pickup apparatus according to claim 5, wherein whether or not to generate an image processing parameter that is not based on characteristic information of a lens attached to the image pickup means is controlled.   The generation means is set to cancel the characteristics of the lens mounted on the imaging means by the setting means, and the white balance correction processing by the color correction means is a white set method or an Auto method, or When the setting unit is set not to cancel the characteristics of the lens mounted on the imaging unit, and the white balance correction processing by the color correction unit is a preset method, the characteristics of the lens mounted on the imaging unit When an image processing parameter that is not based on information is generated, the setting unit is set to cancel the characteristics of the lens mounted on the imaging unit, and the white balance correction processing by the color correction unit is a preset method, Alternatively, the setting unit does not cancel the characteristics of the lens attached to the imaging unit. And when the white balance correction processing by the color correction means is a white set method or an Auto method, an image processing parameter based on characteristic information of a lens attached to the imaging means is generated. The imaging device according to claim 6.   The generation means sets image processing parameters for reflecting the characteristics of the lens in the image data based on the characteristic information of the lens attached to the imaging means according to the color correction processing method by the color correction means. 2. The method according to claim 1, further comprising: controlling whether to generate an image processing parameter for canceling the characteristic of the lens from the image data based on characteristic information of the lens attached to the imaging unit. Imaging device.   When the white balance correction processing by the color correction unit is a white set method or an Auto method, the generation unit generates an image processing parameter for reflecting characteristics of a lens attached to the imaging unit in the image data. The image processing parameter for canceling out the characteristics of the lens mounted on the imaging unit from the image data when the white balance correction processing by the color correcting unit is a preset method. The imaging device described.   The said generation means further produces | generates the image processing parameter which is not based on the characteristic information of the lens with which the said imaging means is mounted irrespective of the system of the color correction process by the said color correction means. The imaging device described in 1. A method for controlling an imaging apparatus having imaging means,
A color correction step of performing color correction processing on the image data captured by the imaging means;
A generation step of generating image processing parameters used for image processing of the image data subjected to color correction processing by the color correction step according to a method of color correction processing by the color correction step. A method for controlling the imaging apparatus. A program for causing a computer that controls an imaging apparatus having an imaging means to execute,
A color correction step of performing color correction processing on the image data captured by the imaging means;
The computer executes a generation step of generating image processing parameters used for image processing of the image data subjected to the color correction processing by the color correction step according to a color correction processing method by the color correction step. Program to let you. Imaging means;
A first color correction process for obtaining a correction value based on the imaged image data and a second color correction process based on a predetermined correction value for the image data picked up by the image pickup means. Applicable color correction means;
When the first color correction process is applied to the image data by the color correction unit, an image for reflecting the color characteristic of the lens in the image data based on the characteristic information of the lens attached to the imaging unit When processing parameters are generated and the second color correction process is applied to the image data by the color correction unit, the color characteristics of the lens are determined based on the characteristic information of the lens mounted on the imaging unit. Generating means for generating an image processing parameter for canceling from the imaging device. Imaging means;
The first color correction processing for canceling the color characteristic of the lens mounted on the imaging unit and the color characteristic of the lens mounted on the imaging unit are not dependent on the image data captured by the imaging unit. Color correction means to which the second color correction processing can be applied;
When the first color correction process is applied to the image data by the color correction unit, image processing for reflecting the characteristics of the lens in the image data based on the characteristic information of the lens mounted on the imaging unit When the parameter is generated and the second color correction process is applied to the image data by the color correction unit, the color characteristic of the lens is determined from the image data based on the characteristic information of the lens attached to the imaging unit. An image pickup apparatus comprising: generation means for generating an image processing parameter for cancellation. A method for controlling an imaging apparatus having imaging means,
A first color correction process for obtaining a correction value based on the imaged image data and a second color correction process based on a predetermined correction value for the image data picked up by the image pickup means. Applicable color correction steps;
When the first color correction process is applied to the image data in the color correction step, the color characteristic of the lens is reflected in the image data based on the characteristic information of the lens attached to the imaging unit. When an image processing parameter is generated and the second color correction process is applied to the image data in the color correction step, the color characteristic of the lens is calculated based on the characteristic information of the lens attached to the imaging unit. And a generation step of generating an image processing parameter for canceling from the image data. A method for controlling an imaging apparatus having imaging means,
The first color correction processing for canceling the color characteristic of the lens mounted on the imaging unit and the color characteristic of the lens mounted on the imaging unit are not dependent on the image data captured by the imaging unit. A color correction step to which the second color correction processing can be applied;
When the first color correction process is applied to the image data in the color correction step, an image for reflecting the characteristics of the lens in the image data based on the characteristic information of the lens attached to the imaging unit When processing parameters are generated and the second color correction process is applied to the image data in the color correction step, the color characteristics of the lens are determined based on the characteristic information of the lens mounted on the imaging unit. And a generation step of generating an image processing parameter for canceling from the data. A program for causing a computer that controls an imaging apparatus having an imaging means to execute,
A first color correction process for obtaining a correction value based on the imaged image data and a second color correction process based on a predetermined correction value for the image data picked up by the image pickup means. Applicable color correction steps;
When the first color correction process is applied to the image data in the color correction step, the color characteristic of the lens is reflected in the image data based on the characteristic information of the lens attached to the imaging unit. When an image processing parameter is generated and the second color correction process is applied to the image data in the color correction step, the color characteristic of the lens is calculated based on the characteristic information of the lens attached to the imaging unit. A program for causing the computer to execute a generation step of generating an image processing parameter for canceling from image data. A program for causing a computer that controls an imaging apparatus having an imaging means to execute,
The first color correction processing for canceling the color characteristic of the lens mounted on the imaging unit and the color characteristic of the lens mounted on the imaging unit are not dependent on the image data captured by the imaging unit. A color correction step to which the second color correction processing can be applied;
When the first color correction process is applied to the image data in the color correction step, an image for reflecting the characteristics of the lens in the image data based on the characteristic information of the lens attached to the imaging unit When processing parameters are generated and the second color correction process is applied to the image data in the color correction step, the color characteristics of the lens are determined based on the characteristic information of the lens mounted on the imaging unit. A program for causing the computer to execute a generation step of generating an image processing parameter for canceling from data.

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