JP2005167735A - Picture data processor, image data processing method, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately execute color correction depending on subjects. <P>SOLUTION: Contents of image data acquired from a subject, a color space mode which is set, and a photographing mode are analyzed. On the basis of the analyzing result, whether a color gamut or gradation is esteemed. According to the determination result, a color correction space is changed for color correction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image data processing apparatus, an image data processing method, and a recording medium that convert data captured by a digital camera into a digital image and process it as image data.

The flow of image processing when image data is taken with a conventional digital camera will be described with reference to FIG.
In step S201, when the shutter button of the digital camera is pressed, light enters the lens.
In S202, the incident light is applied to a sensor such as a CCD or CMOS, and the optical signal is converted into an RGB digital signal.
In S203, interpolation processing is performed on the digitized data, and further processing such as white balance is performed.
In S204, color correction is performed on the data subjected to the interpolation processing in the sRGB color space or a wider AdobeRGB color space, as specified by the user.
In S205, the color corrected data is subjected to gamma processing in accordance with the monitor output.
In S206, JPEG (Joint Photographic Experts Group) compression of the gamma-processed data is performed.

JP 2003-198909 A

FIG. 8 shows the relationship between the sRGB color space and the AdobeRGB color space used for color correction processing.
In the above conventional image processing, in S204, the color space to be color-interpolated is designated by the user. However, since JPEG normally has a bit precision of 8 bits, if the AdobeRGB color space is designated, shooting is performed. Although the color gamut of the processed image data is widened, the gradation is degraded. Such a drop in gradation is particularly noticeable when the subject is a person.

In addition, when the color correction process using the sRGB color space and the color correction process using the AdobeRGB color space have the same bit accuracy, the sRGB color space has better gradation than the AdobeRGB color space.
In other words, when the subject is a landscape other than a person, the color gamut is emphasized, so it is preferable to specify the AdobeRGB color space. On the other hand, when the subject is a person, the skin tone gradation is emphasized. It is better to specify the space. In this way, the color space at the time of color correction should be switched individually according to the subject to be photographed, but in conventional color correction processing, whether to emphasize color gamut or gradation is important. Color correction is not performed according to the subject content.
Accordingly, an object of the present invention is to provide an image data processing apparatus, an image data processing method, and a recording medium that can perform color correction processing more appropriately according to the subject.

The present invention provides an imaging unit that acquires imaging data, a shooting mode setting unit that sets a shooting mode at the time of shooting, a plurality of color correction information for performing tone correction or color gamut-oriented color correction, Analyzing means for analyzing imaging data and the photographing mode and determining whether to emphasize gradation or color gamut, and based on the analyzed result, the desired color correction from the plurality of color correction information Color correction space selection means for selecting information, and color correction means for performing color correction of the acquired imaging data corresponding to the selected color correction information and generating color-corrected image data Thus, an image data processing apparatus is configured.
The shooting mode may be a person, landscape, night view, or automatic mode when acquiring the shooting data.

The color correction unit may generate image data color-corrected using color correction information with emphasis on gradation when it is determined that gradation is important from the analysis result of the photographing data by the analysis unit. Good.
If the color correction unit determines that the color correction information corresponding to the set color space mode is different from the color correction information actually used in the color correction process based on the analysis result by the analysis unit, Two types of data, tonality-oriented image data and color gamut-oriented image data, may be generated.
The color space mode may be a tone-oriented, color-gamut-oriented, or automatic mode.
The image processing apparatus may further include a storage unit that stores the generated image data.

  The present invention analyzes an imaging step of acquiring imaging data, a shooting mode setting step of setting a shooting mode at the time of shooting, the imaging data and the shooting mode, and each of them determines whether to emphasize gradation or color gamut. An analysis step for determining, a color correction space selecting step for selecting desired color correction information from the plurality of color correction information based on the analyzed analysis result, and the selected color correction information. The image data processing method is provided by including a color correction step of performing color correction of the acquired imaging data and generating color-corrected image data.

The present invention provides a recording medium by recording image data generated by the image data processing method.
The present invention analyzes photographed image data, and converts the photographed image data into image data in a color space selected from the first and second color space transformations from the result of the image data analysis means. An image data processing method is provided by including color conversion means and image data storage means for storing the image data converted by the color space conversion means in a recording medium.
The first color space may be an sRGB color space.
The second color space may be an AdobeRGB color space.

The image data analysis means may perform face recognition processing on the image data.
The image data analysis means may perform skin color recognition processing on the image data.

  According to the present invention, the contents of the image data obtained from the subject, the set color space mode, and the shooting mode are analyzed, and whether the color gamut or gradation is emphasized based on the analysis result. Since the color correction processing is performed by switching the color correction space according to the determination result, the color correction processing can be performed more appropriately according to the subject.

Embodiments of the present invention will be described below with reference to the drawings.
[First example]
A first embodiment of the present invention will be described with reference to FIGS.
FIG. 2 shows a system configuration example of a digital camera according to the present invention.
This system includes an input device 101, a display device 102, a storage device 103, a CPU 104, a ROM 105, and a RAM 106.
The input device 101 is a device for inputting instructions and data from a user, and includes a pointing system such as a keyboard and a mouse.
The display device 102 is a device that displays a GUI (Graphical User Interface) or the like, and usually a CRT, a liquid crystal display, or the like is used.
The storage device 103 is a device for storing image data and programs, and normally a hard disk is used.
The CPU 104 performs overall control of the present system, processing of each of the above components, image data processing of the present invention, and the like.
The ROM 105 and the RAM 106 are used as a storage area for programs related to various control processes, a storage area for imaging data and image data, a work area for various processes, and the like.
A control program 10 relating to image data processing as shown in the flowcharts of FIGS. 1 and 7 according to the present invention can be stored in the storage device 103 or the ROM 105. If it is stored in the storage device 103, it is once read into the RAM 106 and executed.

FIG. 3 shows an external configuration of a digital camera that captures a JPEG file.
The digital camera 300 is provided with a mode dial 303 for changing the shooting mode. By rotating the mode dial 303, four types of shooting modes at the time of shooting can be changed.

FIG. 4 shows an example of the shooting mode.
The shooting modes include a person shooting mode 306 for shooting a person, a landscape shooting mode 307 for shooting a landscape, a night view shooting mode 308 for shooting a night view, and automatic shooting used for shooting most other scenes. There is a mode 309.
Each time the mode dial 303 is rotated, these shooting modes are changed, and the currently selected mode is displayed as an icon as a selection mode 305 on the liquid crystal panel 304.
Then, when the shutter button 302 is pressed, a JPEG image is shot according to the currently selected shooting mode.

FIG. 5 shows a rear configuration of the digital camera 300.
A liquid crystal display 402 is provided on the back surface 401 of the digital camera 300. The liquid crystal display 402 displays a UI (User Interface) for performing various settings of the digital camera 300. The UI operation is performed using the operation buttons 404a to 404d.

FIG. 6 shows an example of the operation screen 405 for setting the color space mode.
On the operation screen 405, an sRGB mode 411, an AdobeRGB mode 412 and an automatic selection mode 413 are displayed in order to switch the color space during shooting. The sRGB mode 411 is a mode for executing color correction processing using the sRGB color space, and the AdobeRGB mode 412 is a mode for executing color correction processing using the AdobeRGB color space. These sRGB color space and AdobeRGB color space are defined by the color gamut as shown in FIG.

When selecting these color spaces, the UI of the operation screen 405 on the liquid crystal display 402 is displayed, and the color space can be designated by selecting one of the three color space modes 411 to 413.
However, when the automatic selection mode 413 is set, the content of the captured image of the subject is determined with priority given to the setting content of the shooting modes 306 to 309, and the gradation characteristics are determined based on the determination result. It is possible to automatically recognize whether or not the emphasis is placed on the color gamut.

Hereinafter, the operation of this apparatus will be described.
FIG. 1 shows a flowchart of image data processing according to the present invention.
In this example, a description will be given of color correction processing when “automatic selection mode 413” is selected as the color space when a subject is photographed by the digital camera 300.
In step S501, the “automatic selection mode 413” is set as the color space on the operation screen 405.
In step S502, the shutter button 403 is pressed to photograph the subject.
In step S503, a subject is photographed using a photographing element such as a CCD sensor, and an optical signal that is the photographed data is converted into an RGB digital signal to obtain digitized image data.
In step S504, interpolation processing and white balance adjustment are performed on the digitized image data.
In step S <b> 505, the shooting mode used for shooting is read from the selection mode 305 of the liquid crystal panel 304. The shooting mode at this time is one of the shooting modes 306 to 309 in FIG.
In step S506, the shooting mode, color space mode, and the content of the captured image data at the time of shooting are analyzed, and it is determined from these analysis results whether to emphasize gradation or color gamut.
Specifically, since the automatic selection mode 413 is set as the color space, the determination as to whether or not to emphasize gradation is determined with priority given to the setting contents of the shooting mode at the time of shooting. Thereby, for example, when the shooting mode at the time of shooting is the person shooting mode 306, it is determined that the gradation is important, and the process proceeds to S507.

On the other hand, in S506, when the mode other than the person is the landscape shooting mode 307, the night scene shooting mode 308, or the automatic shooting mode 309, it is determined that a wider color gamut is important, and the process proceeds to S510.
In step S507, the image data is subjected to a 3 × 3 matrix operation as an n × m matrix operation for the sRGB color space (n and m are integers of 2 or more), and color correction is performed in the sRGB color space. As a result, the image data is converted into an area 60 surrounded by a dotted line in the sRGB color space of FIG.
In S510, a 3 × 3 matrix operation is performed on the image data as an n × m matrix operation for the AdobeRGB color space, and color correction is performed on the AdobeRGB color space. As a result, the image data is converted into an area 70 surrounded by a solid line in the AdobeRGB color space in FIG.

As is apparent from FIG. 8, the sRGB color space and the AdobeRGB color space have a wider color gamut, so if the bit precision is the same, the sRGB color space has the AdobeRGB color space. Compared to the color space, the gradation is increased by about 140%.
In step S508, gamma correction is performed for the monitor on the color-corrected image data.
In step S509, the color-corrected image data is JPEG compressed and saved as a file. When saving the data, the shooting mode used for shooting is added to the header of the file as image additional information.

  As described above, the shooting mode set at the time of shooting, the color space mode, and the content of the shot data are analyzed, and it is determined from the analysis result whether or not the subject is mainly a person. It is possible to automatically identify whether the area is important. As a result of such image data processing, when a person or the like is a subject, image data having a rich gradation can be created, and when a landscape or the like is a subject, a rich color gamut Can be created.

Next, a modified example will be described.
When the automatic selection mode 413 is set as the color space mode and the automatic shooting mode 309 is set as the shooting mode, the following processing may be performed in the analysis processing of S506 in FIG.
Specifically, the data content of the photographed subject is analyzed, and the color space is automatically switched on the camera side according to the analysis result. For example, in consideration of focal length, magnification, shutter speed, etc., the content of the photographic data is analyzed, and when it is determined that the data is mainly a person, an sRGB color space that emphasizes gradation is selected, If it is determined that the data is mainly scenery other than a person, the AdobeRGB color space with an emphasis on the color gamut is selected. Then, color correction processing may be executed in S507 or S510 using the selected color space.

[Second example]
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, about the same part as the 1st example mentioned above, the description is abbreviate | omitted and the same code | symbol is attached | subjected.

  In this example, as another example of image data processing, when the subject is photographed with the digital camera 300, “Adobe RGB mode 412” is selected as the color space, and “person photographing mode 306” is selected as the photographing mode. The color correction process will be described.

In step S <b> 601, the color space is set to “Adobe RGB mode” using the selection mode 305.
In step S602, the shutter button 403 is pressed to photograph the subject.
In step S603, the subject is photographed using a photographing element such as a CCD sensor, and an optical signal that is the photographed data is converted into an RGB digital signal to obtain digitized image data.
In step S604, interpolation processing and white balance adjustment are performed on the digitized image data.
In step S605, the person photographing mode 306 is read as the photographing mode used for photographing.
In step S606, the shooting mode, color space mode, and the content of the captured image data at the time of shooting are analyzed, and from these analysis results, it is determined whether to emphasize tone or color gamut.
Specifically, since the shooting mode at the time of shooting is the person shooting mode 306, it is determined that gradation is important and the process proceeds to S607.
Note that, in the case of landscape shooting mode 307, night scene shooting mode 308, and automatic shooting mode 309 other than a person, it is determined that a wider color gamut is important, and the process proceeds to S611. Because of this process, the explanation is omitted.

In step S607, 3 × 3 matrix calculation is performed on the processed image data (hereinafter referred to as image data A) as an n × n matrix calculation for the sRGB color space, and color correction is performed on the sRGB color space. As a result, the image data is converted into an area 60 surrounded by a dotted line in the sRGB color space of FIG.
In step S608, the color-corrected image data A is subjected to gamma correction for monitoring.
In step S609, the image data A is JPEG compressed and saved as a file. At the time of this storage, the shooting mode used for shooting is added to the header of the file as image additional information.
In S610, it is checked whether the color space designated in S601 and the color space actually color-corrected in S607 are the same.
If it is determined that the inspection results are the same, the process ends. On the other hand, if it is determined that the inspection results are not the same, the process proceeds to S611.
In step S611, 3 × 3 matrix calculation is performed on the image data A as an n × n matrix calculation for the AdobeRGB color space, and color correction is performed on the AdobeRGB color space. Image data generated as a result of the color correction is referred to as image data B. The image data B is converted into an area 70 surrounded by a solid line in the AdobeRGB color space in FIG.

As is apparent from FIG. 8, the sRGB color space and the AdobeRGB color space have a wider color gamut, so if the bit accuracy is the same, the sRGB color space has a gradation. Sex is better.
Thereafter, the image data B is processed in S610. This time, the color space specified in S601 and the color space actually color-corrected in S611 are both the AdobeRGB color space and are the same. Exit.

As a result of the above processing, when the Adobe RGB color space is specified in S601 and the shooting mode is the person shooting mode 306, S606 → S607 → S608 → S609 → S610 → S611 → S608 → S609 → S610 → End The process proceeds. As a result, two types of image files are generated: image data A that has been color corrected to the sRGB color space, and image data B that has been color corrected to both the sRGB color space and the AdobeRGB color space.
As a result, even when there is a reduction in gradation in the image data B color-corrected in the AdobeRGB color space designated by the user, the image data A color-corrected in the sRGB color space is also stored, so the image was taken. Valuable data can be saved.

Next, a modified example will be described.
It is assumed that a person picture is taken at a night indoor party or the like. In such a case, when “Adobe RGB mode 412” is selected as the color space and “night scene shooting mode 308” is selected as the shooting mode, the night scene shooting mode 308 is set in the normal processing. In step S611, it is determined that the image data is not a person, and only one image data color-corrected in the AdobeRGB color space is generated.

  However, in the analysis processing of S606 in the present invention, the result of performing skin color recognition by identifying from the hue information for skin color determination whether the skin color portion exists in the shooting data, rather than determining only by the shooting mode, Based on the skin color recognition result, identify a region where skin color exists, approximate the region to an ellipse, and (1) a pair of eye regions exists at a predetermined position within the ellipse, or (2) nose, mouth, etc. Focusing on gradation characteristics by comprehensively analyzing the contents of shooting data based on the result of face recognition by identifying whether there is an organ area of the image, and other color space mode settings Therefore, even if the night scene shooting mode 308 is set, if the result of the analysis in S606 determines that the subject is mainly a person, the process proceeds to S607, and the color in the sRGB color space is determined. One corrected image data A is generated, and since the color space is different in S610, the process proceeds to S611, where another image data B color-corrected in the AdobeRGB color space is generated, and two types of image data are generated. Since the image is stored, it is possible to generate a delicate image with a sense of realism according to the shooting situation.

  The above-described example can be applied to an imaging apparatus such as a digital camera. However, in addition to this, even when applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.) You may apply to the apparatus which consists of one apparatus (For example, a small image processing apparatus like a PDA (personal information management) apparatus, a copying machine, a facsimile machine).

  Needless to say, the present invention can also be applied to a case where the present invention is achieved by supplying a program to a system or apparatus. Then, a storage medium storing a program represented by software for achieving the present invention is supplied to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the program code stored in the storage medium It is possible to enjoy the effects of the present invention also by reading and executing.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, and a nonvolatile memory card (IC memory card). ROM (mask ROM, flash EEPROM, etc.) can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written in the memory of the function expansion unit inserted in the computer or the function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a flowchart which shows the image data processing of the digital camera which is the 1st Embodiment of this invention. It is a block diagram which shows the system configuration | structure of a digital camera. It is a perspective view which shows the external appearance structure of a digital camera. It is explanatory drawing which shows imaging | photography mode. It is a perspective view which shows the back surface structure of a digital camera. It is explanatory drawing which shows color space mode also on the operation screen. It is a flowchart which shows the image data processing of the digital camera which is the 2nd Embodiment of this invention. It is explanatory drawing which shows the color gamut of sRGB color space and AdobeRGB color space. It is a flowchart which shows the conventional image data processing.

Explanation of symbols

10 control program 101 input device 102 display device 103 storage device 104 CPU
105 ROM
106 RAM
300 Digital Camera 302 Shutter Button 303 Mode Dial 304 Liquid Crystal Panel 305 Selection Mode 306 Portrait Shooting Mode 307 Landscape Shooting Mode 308 Night View Shooting Mode 309 Automatic Shooting Mode 401 Rear 402 Liquid Crystal Display 403 Shutter Buttons 404a to 404d Operation Buttons 411 sRGB Mode 412 AdobeRGB Mode 413 Automatic selection mode

Claims (13)

Imaging means for acquiring imaging data;
Shooting mode setting means for setting a shooting mode at the time of shooting;
A plurality of color correction information for performing gradation correction or color gamut-oriented color correction,
Analysis means for analyzing the imaging data and the shooting mode, and determining whether to emphasize gradation or color gamut;
Color correction space selection means for selecting desired color correction information from the plurality of color correction information based on the analyzed analysis results;
An image data processing apparatus, comprising: color correction means for performing color correction of the acquired imaging data corresponding to the selected color correction information and generating color-corrected image data.   The image data processing apparatus according to claim 1, wherein the shooting mode is a person, landscape, night view, or automatic mode when acquiring the shooting data. The color correction means includes
2. The image data that has been color-corrected using color correction information that emphasizes gradation is generated when it is determined that gradation is important from the analysis result of the photographing data by the analysis unit. Or the image data processing apparatus of 2 description. The color correction means includes
If it is determined that the color correction information corresponding to the set color space mode is different from the color correction information actually used for the color correction processing based on the analysis result by the analyzing means, the image data emphasizing gradation The image data processing apparatus according to claim 1, wherein two types of data, i.e., image data with emphasis on color gamut, are generated.   5. The image data processing apparatus according to claim 1, wherein the color space mode is a gradation-oriented, color-gamut-oriented, or automatic mode.   6. The image data processing apparatus according to claim 1, further comprising storage means for storing the generated image data. An imaging process for acquiring imaging data;
A shooting mode setting process for setting a shooting mode at the time of shooting;
Analyzing the imaging data and the shooting mode, and determining each of whether to emphasize gradation or color gamut;
A color correction space selection step of selecting desired color correction information from the plurality of color correction information based on the analyzed analysis result;
An image data processing method comprising: a color correction step of performing color correction of the acquired imaging data corresponding to the selected color correction information and generating color-corrected image data.   8. A recording medium for recording image data generated by the image data processing method according to claim 7. A color conversion unit that analyzes the captured image data and converts the captured image data into image data of a color space selected from the first and second color space conversions from the result of the image data analysis unit;
An image data processing method comprising image data storage means for storing the image data converted by the color space conversion means in a recording medium.   The image data processing method according to claim 9, wherein the first color space is an sRGB color space.   10. The image data processing method according to claim 9, wherein the second color space is an AdobeRGB color space.   The image data processing method according to claim 9, wherein the image data analysis means is to perform face recognition processing on the image data. The image data processing method according to claim 9, wherein the image data analysis means is to perform a skin color recognition process on the image data.

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