JP2003235050A - Image processing apparatus, image processing program, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly decide a degree of adjustment for color reproducibility of an image signal. <P>SOLUTION: The image processing apparatus of this invention collects information related to colors giving effect on color expression of the image signal (e.g. photometry value of a camera, photometry contrast, information of flash light emission, exposure condition of the camera, and color aberration of an imaging lens or the like). The information related to colors gives effects on brightness of colors of the image signal, color saturation, color slippage, and noise or the like. Then the image processing apparatus of this invention grasps a state of color expression of the image signal from the information related to colors and controls a degree of adjustment for the color reproducibility (e.g. saturation) depending on the state. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus and method for adjusting color reproducibility of an image signal generated by an image pickup section. The present invention relates to an image processing program for realizing this image processing device on a computer.

[0002]

2. Description of the Related Art Conventionally, there is known an electronic camera in which a user manually selects the degree of adjustment of color reproducibility from a plurality of setting levels. In such an electronic camera, when the user selects "a setting level that emphasizes saturation most", an image signal with vivid colors can be generated. Such an image signal becomes an image signal suitable for applications such as printing as it is on a printer and posting it on a home page as it is.

Further, when the user manually selects "a setting level which does not emphasize chroma very much", it is possible to generate an image signal in which color saturation is prevented. Such an image signal contains abundant delicate color information and becomes an image signal suitable for image processing and processing on a personal computer. Thus, in the conventional electronic camera,
It was possible for the user to change the degree of color reproducibility adjustment by manual selection.

[0004]

By the way, the color expression of the image signal is sensitively changed depending on the color temperature of the light source, the color and brightness of the object, and the image pickup conditions of the electronic camera. Without considering such a change in color expression, for example,
When the above-mentioned “setting level that emphasizes saturation most” is selected, there are concerns that the saturation may be emphasized more than necessary and the color may be unnatural. The present invention has been made in view of such problems, and an object thereof is to accurately determine the adjustment degree of color reproducibility for various image signals.

[0005]

The present invention will be described below. <Claim 1> An image processing apparatus according to claim 1 is an image processing apparatus for processing an image signal generated by an imaging unit, and includes a color reproducibility adjusting unit and a color reproducibility control unit. The color reproducibility adjusting unit adjusts the color reproducibility of the image signal by changing at least the saturation. On the other hand, the color reproducibility control unit obtains color-related information that affects the color expression of the image signal, and controls the degree of adjustment of the color reproducibility according to this color-related information. By such an operation, it is possible to cope with a change in color expression inferred from color-related information,
It is possible to control the degree of adjustment of color reproducibility. <Claim 2> The image processing apparatus according to claim 2 adopts the image pickup condition of the image signal as at least one of the color-related information. As the image capturing condition, for example, a setting condition relating to the image capturing operation of the electronic camera, a condition of a subject environment at the time of image capturing, or the like is applicable. The color reproducibility control unit acquires information on such an imaging condition and controls the degree of adjustment of color reproducibility according to the imaging condition. By such operation,
It is possible to control the degree of adjustment of the color reproducibility by coping with the change in the color expression inferred from the imaging condition. <Claim 3> The image processing apparatus according to claim 3 employs the analysis result of the image signal as at least one of the color-related information. The color reproducibility control unit acquires information on such an analysis result and controls the degree of adjustment of color reproducibility according to the analysis result. By such an operation, it becomes possible to control the degree of adjustment of the color reproducibility by coping with the change in the color expression inferred from the analysis result. <Claim 4> The image processing apparatus according to claim 4 employs a photometric value of the object scene as at least one of the imaging conditions. The color reproducibility control unit acquires information on a photometric value when an image signal is picked up, and controls the degree of adjustment of color reproducibility according to the photometric value. By such an operation, it is possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression of the image signal estimated from the photometric value. <Claim 5> The image processing apparatus according to claim 5 adopts the divided photometric value of the object scene as at least one of the imaging conditions.
The color reproducibility control unit acquires information on the divided photometric value when the image signal is picked up, and controls the adjustment degree of the color reproducibility according to the photometric contrast obtained from the divided photometric value. By such an operation, it becomes possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression estimated from the photometric contrast. <Claim 6> The image processing apparatus according to claim 6 employs illumination information on the subject illumination as at least one of the imaging conditions. The color reproducibility control unit acquires information on illumination information when the image signal is captured, and controls the degree of adjustment of color reproducibility according to the illumination information. By such an operation, it becomes possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression estimated from the illumination information. <Claim 7> The image processing apparatus according to claim 7 employs the exposure condition of the imaging unit as at least one of the imaging conditions. The color reproducibility control unit acquires information on the exposure condition when the image signal is captured, and controls the degree of adjustment of the color reproducibility according to this exposure condition. By such an operation, it becomes possible to control the degree of adjustment of the color reproducibility by coping with the change in the color expression estimated from the exposure condition. <Claim 8> The image processing apparatus according to claim 8 employs lens information about the lens of the imaging unit as at least one of the imaging conditions. The color reproducibility control unit acquires information on lens information when the image signal is captured, and controls the degree of adjustment of color reproducibility according to the lens information. By such an operation, it becomes possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression estimated from the lens information. <Claim 9> The image processing apparatus according to claim 9 employs the imaging sensitivity of the imaging unit as at least one of the imaging conditions. The color reproducibility control unit acquires information on the image pickup sensitivity when the image signal is picked up, and controls the adjustment degree of the color reproducibility according to the image pickup sensitivity. By such an operation, it becomes possible to control the degree of adjustment of color reproducibility by coping with the change in color expression estimated from the imaging sensitivity. <Claim 10> The image processing apparatus according to claim 10 employs color information relating to the color of the image signal as at least one of the analysis results. The color reproducibility control unit acquires information on the color information of the image signal, and controls the degree of adjustment of the color reproducibility according to this color information. By such an operation, it is possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression determined from the color information. <Claim 11> The image processing apparatus according to claim 11 employs, as at least one of the analysis results, a color concentration degree indicating a screen occupation degree of a color in an image signal. The color reproduction control unit
Information on the degree of color concentration of the image signal is acquired, and the degree of adjustment of color reproducibility is controlled according to the degree of color concentration. By such an operation, it becomes possible to control the adjustment degree of the color reproducibility by coping with the change in the color expression determined from the degree of color concentration. <Claim 12> The image processing program according to claim 12 causes a computer to execute any one of claims 1 to 11.
The color reproducibility adjusting unit and the color reproducibility controlling unit described in the above section are made to function. <Claim 13> The image processing method according to claim 13 is an image processing method for performing image processing on an image signal generated by an image pickup unit, and obtains "color-related information affecting color expression" for the image signal. However, the method further includes a step of determining an adjustment degree of color reproducibility according to the color-related information, and a step of adjusting at least the saturation according to the determined adjustment degree to adjust the color reproducibility of the image signal. And

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[Schematic Description of Electronic Camera 11] FIG. 1 is a diagram illustrating a configuration of an electronic camera 11 (including an image processing apparatus) of the present embodiment. First, the configuration and operation of the electronic camera 11 will be briefly described with reference to FIG. Figure 1
In, the electronic camera 11 is equipped with the taking lens 12. Inside the photographing lens 12, the MP inside the lens
U12a is built in. A light receiving surface of the image pickup device 13 is arranged on the image space side of the taking lens 12 with a shutter mechanism (not shown) interposed therebetween.

The image signal output from the image pickup device 13 is output to the A / D converter 16 after gain adjustment according to the image pickup sensitivity in the amplifier 14. The A / D conversion unit 16 digitizes this image signal pixel by pixel and outputs it to the white balance processing unit 17, the color distribution evaluation unit 17a, and the brightness distribution evaluation unit 25. Color distribution evaluation unit 17a
Calculates the estimated value of color temperature by evaluating the color distribution of this image signal. The white balance processing unit 17 performs white balance adjustment on the image signal according to the estimated value of the color temperature.

The interpolation processing section 18 performs interpolation processing of the missing signal component on the image signal after the white balance adjustment. The noise suppression unit 19 performs noise suppression processing such as local sum-of-products calculation on the image signal after the interpolation processing. The gamma conversion unit 20 performs gradation conversion on the noise-suppressed image signal and outputs it to the matrix conversion unit 21.

The matrix conversion section 21 performs color coordinate conversion of the gradation-converted image signal into a signal component such as YCbCr. At this time, the matrix conversion unit 21 adjusts the color reproducibility of the entire image by uniformly controlling the conversion gain of the color-related signal component CbCr for the entire image. The conversion gain of the color signal component (that is, the adjustment value of color reproducibility) is controlled based on the adjustment tendency rule described later.

The matrix conversion section 21 outputs the luminance component Y to the contour adjustment section 22 and the color difference component CbCr whose color reproducibility is adjusted to the color noise suppression section 23. The contour adjusting unit 22 performs contour enhancement processing such as unsharp masking on the luminance component Y. On the other hand, in the color noise suppression unit 23, the color difference component CbC is generated according to the signal level of the luminance component Y.
By changing the signal gain of r, color noise that is likely to appear in the dark portion or high luminance portion of the image is suppressed. (After completing such a series of signal processing, in the electronic camera 11,
The image signal YCbCr is subjected to processing such as compression and recording / saving. )

In addition to the above-described signal processing configuration, a split photometric sensor 29, a built-in or external flash device 30, are provided in the electronic camera 11 as a configuration for an imaging operation.
And a photographing control unit 31 is provided. The divided photometric sensor 29 performs the divided TTL (Through The Lens) system or the direct divided photometry on the object field, and outputs the divided photometric values. Based on this divided photometric value, the shooting control unit 31 determines the exposure condition at the time of shooting, and determines the aperture value of the shooting lens 12, the shutter speed of the image sensor 13, the imaging sensitivity (gain) of the amplifier 14, and the flash device 30. The light emission timing and the like are controlled respectively. Further, the electronic camera 11 is provided with a color reproducibility control unit 24 as a characteristic component of the present invention.

[Correspondence Relationship with Invention] The correspondence relationship between the matters described in the claims and the present embodiment will be described below. It should be noted that the correspondence relationship here is one interpretation for reference, and the present invention is not limited to these. The imaging section described in the claims corresponds to the taking lens 12, the imaging element 13, the amplifier 14, and the imaging control section 31. The color reproducibility adjusting unit described in the claims corresponds to the “variable function of the conversion gain of the color difference component CbCr” of the matrix converting unit 21. The color reproducibility control unit described in the claims corresponds to the color reproducibility control unit 24.

[Explanation of Operation of Color Reproducibility Control Unit 24] FIG.
6 is a flowchart illustrating the operation of the color reproducibility control unit 24. The operation of the color reproducibility control unit 24 will be described below in the order of step numbers in FIG.

Step S1: The color reproduction control section 24
For the image signal to be processed, color-related information that affects the color expression of the image signal is acquired. The "color expression" means how colors look when an image signal is displayed or printed. For example, as "color expression", vividness and crispness of color, dullness of color, bias of hue, color tone (high key, low key, temperature control, cold control, etc.), subtle difference in color appearance, How to see the color of the flat part,
Edge color appearance, detail color appearance, dark area color appearance, highlight area color appearance, color shift,
Unnatural coloring or color noise is applicable. The color reproducibility control unit 24 collects the following color-related information, for example. (A) Photometric value of the divided photometric sensor 29 (divided photometric value) (B) Illumination information transmitted from the flash unit MPU 30a (C) Exposure condition transmitted from the photographing control unit 31 (D) Transmitted from the lens MPU 12a Lens information (E) Imaging sensitivity (F) transmitted from photographing control section 31 Color information transmitted from color distribution evaluation section 17a (for example, color temperature of light source, hue angle, saturation, etc.) (G) Color distribution Color concentration degree transmitted from the evaluation unit 17a (value indicating screen occupation degree of color)

Step S2: The color reproduction control section 24
Each of these color-related information is normalized according to the normalization table shown in FIG. The proper step of normalization greatly varies depending on the characteristics of the image sensor 13 used. Therefore, it is preferable to perform an image pickup experiment of the electronic camera 11 to obtain the influence of the color-related information on the color expression, and normalize the color-related information having a larger influence in finer increments.

Step S3: The color reproduction control section 24
A unique data reference address is generated by combining the normalized values of individual color-related information. This data reference address corresponds to the address of the internal data area of the color reproduction control unit 24. In this internal data area, matrix coefficient data according to each rule described later is stored corresponding to each combination of normalized values.

Step S4: The color reproduction control section 24
The internal data area is referred to based on this data reference address to obtain the matrix coefficient of the color coordinate conversion matrix.
The color reproducibility control unit 24 transfers the matrix coefficient thus obtained to the matrix conversion unit 21. The matrix conversion unit 21 uses this matrix coefficient to execute color coordinate conversion of the image signal. (At this time, the conversion gain of the signal component CbCr is changed by the matrix coefficient, so that the color reproducibility of the entire image is adjusted.)

[Regarding Adjustment Tendency of Color Reproducibility] In each electronic camera, the optimum adjustment value of color reproducibility varies greatly depending on the difference in the dynamic range and noise characteristics of the image pickup device 13 used. Therefore, in this specification, instead of giving a specific adjustment value for each electronic camera, a more essential "color reproducibility adjustment tendency" will be described in detail. A person skilled in the art can specifically implement the present embodiment by changing a predetermined standard matrix coefficient (hereinafter referred to as “standard value”) according to the adjustment tendency to be described below.

(1) Color Reproducibility Adjustment Tendency Based on Photometric Contrast The color reproducibility control section 24 obtains information on divided photometric values from the divided photometric sensor 29. The division photometric value is a value obtained by subjecting the object field to division photometry. The color reproducibility control unit 24 obtains the photometric contrast of the object scene by obtaining the brightness level difference (or ratio) for this divided photometric value. FIG. 4 is a diagram showing an adjustment tendency of color reproducibility based on the photometric contrast. Generally, as the photometric contrast increases, the change width of the color signal in the image signal increases, and the risk of color saturation increases. Therefore, as shown in FIG. 4, the color reproducibility control unit 24 controls the degree of saturation adjustment to be lower than the standard value as the photometric contrast increases. As a result, in a situation where the photometric contrast is higher than usual, the saturation is not overemphasized and color saturation is less likely to occur. As a result, the loss of color information due to color saturation is reduced, and it becomes possible to accurately store subtle color differences. On the contrary, in the situation where the photometric contrast is low, the change width of the brightness of the image signal becomes small, and the change in the color also looks plain. Therefore, as shown in FIG. 4, the color reproducibility control unit 24 adjusts the degree of saturation adjustment higher than the standard value as the photometric contrast decreases. as a result,
In a situation where the photometric contrast is lower than usual, it is possible to obtain an image signal in which the saturation is moderately emphasized and the color is sharp.

(2) Color Reproducibility Adjustment Tendency Based on Hue and Color Concentration The color reproducibility control unit 24 acquires color distribution information of the image signal from the color distribution evaluation unit 17a. Color reproduction control unit 24
Analyzes the hue and the degree of color concentration of the image signal based on the color distribution information. In this case, the "hue" is the hue of the main range of the image (such as the center of the screen or the AF selection area), the hue that frequently appears on the entire screen, the hue of a large area in the image, or the hue of the entire image. Is preferable. Further, the “color concentration degree” means the screen occupation degree of the color in the image signal. For example, as a method of analyzing the hue and the degree of color concentration, a method of statistically processing the hue component of the image signal and obtaining the histogram statistics of the hue is simple and preferable. In this case, it is possible to obtain the hue having a high appearance frequency and the appearance frequency (corresponding to the degree of color concentration) for each hue together. FIG. 5 is a diagram showing the adjustment tendency of the color reproducibility based on the hue and the degree of color concentration. That is, the color reproducibility control unit 24
When it is determined that the degree of color concentration in the hue of the red region is higher than the evaluation standard, the saturation enhancement of red is set higher than the standard value. In this case, it is possible to vividly emphasize the main red region (sunset, red flower, etc.) in the image signal. If the color reproducibility control unit 24 determines that the degree of color concentration is higher than the evaluation standard in the hue in the green region, it sets the saturation enhancement of green higher than the standard value. In this case, it becomes possible to emphasize the main green region (grassland, vegetation, etc.) in the image signal as brightly as fresh green. Furthermore, when the color reproducibility control unit 24 determines that the degree of color concentration in the hue of the blue region is higher than the evaluation standard,
Set the saturation enhancement of blue higher than the standard value. In this case, the main blue region (blue sky or the like) in the image signal can be vividly enhanced.

(3) Color Reproducibility Adjustment Tendency Based on Color Temperature The color reproducibility control section 24 obtains from the color distribution evaluation section 17a the information on the color temperature (estimated value) of the light source which is the judgment material for the white balance adjustment. . Note that the color temperature may be estimated from the white color set by the user in the preset white balance, instead of obtaining the image signal as a determination factor. Further, the color temperature may be estimated from the manually set value of the white balance. FIG. 6 is a diagram showing the adjustment tendency of the color reproducibility based on this color temperature. When the color temperature at the time of image pickup deviates from the standard range of the color temperature assumed by the color filter array of the image pickup device 13, the level difference between the signal components output from the image pickup device 13 (between RGB, etc.) becomes large. In this case, since the exposure condition is determined within the range in which the largest signal component is not saturated, the signal level becomes low for the smallest signal component and the S / N deteriorates. If the saturation is excessively emphasized in such a state, the image signal will have a poor S / N feeling. Therefore, as shown in FIG. 6, the color reproducibility control unit 24 sets an upper limit for the saturation enhancement so that the saturation of blue is not excessively increased when the color temperature falls outside the standard range and becomes low. As a result, even if saturation is emphasized by other factors,
The saturation (especially the saturation of blue) is no longer overemphasized. Further, as shown in FIG. 6, the color reproducibility control unit 24 sets an upper limit on the saturation enhancement so that the saturation of red color does not rise too much when the color temperature rises outside the standard range.
As a result, the saturation (especially the saturation of red) is not overemphasized even if the saturation is emphasized by other factors. By adjusting the color reproducibility based on such color temperature,
It is possible to improve the situation where the noise of the image signal becomes noticeable.

(4) Adjustment tendency of color reproducibility based on saturation The color reproducibility control section 24 acquires the color distribution information of the image signal from the color distribution evaluation section 17a. Color reproduction control unit 24
Analyzes the saturation of the image signal based on this color distribution information. The "saturation" in this case means the saturation of the main area of the image (the center of the screen, the AF selection area, etc.), the saturation that frequently appears on the screen, the saturation of a large area in the image, The average value of the saturation of the entire image is preferable. FIG. 7 is a diagram showing an adjustment tendency of color reproducibility based on this saturation. The saturation of an image signal close to a black and white image or an image signal of high key expression or low key expression is generally low. In the case of such a low-saturation image signal, if the saturation is simply emphasized, it is likely to cause a problem such as being out of the user's shooting intention or adding an extra color. Therefore, the color reproducibility control unit 24
As shown in FIG. 7, when the saturation of the image signal falls out of the standard range and becomes low, an upper limit is set for the saturation emphasis so that the saturation is not emphasized beyond this upper limit. On the other hand, an image signal showing a colorful subject has high saturation. In the case of such a high saturation image signal, if saturation is simply emphasized, a problem such as color saturation is likely to occur. Therefore, as shown in FIG. 7, when the saturation of the image signal goes out of the standard range and becomes high, the color reproducibility control unit 24 sets an upper limit on the saturation emphasis and emphasizes the saturation above this upper limit. Try not to.

(5) Color reproducibility adjustment tendency based on photometric values The color reproducibility control section 24 acquires information on the divided photometric values from the divided photometric sensors 29. The color reproducibility control unit 24 obtains a photometric value based on this divided photometric value. In this case, the "photometric value" includes the photometric value of the main area of the image (the center of the screen, the AF selection area, etc.), the minimum, maximum, or intermediate split photometric value, or the photometric value of a large area in the image. An average value of divided photometric values of the entire image is preferable. FIG. 8 is a diagram showing an adjustment tendency of color reproducibility based on this photometric value. If the photometric value is extremely low, the S / N ratio of the image signal will deteriorate. In this case, if the saturation is emphasized excessively, noise in the image signal becomes more noticeable than necessary. Therefore, the color reproducibility control unit 2
No. 4, as shown in FIG. 8, when the photometric value falls outside the standard range and becomes low, an upper limit is set for the saturation emphasis, and the saturation is not emphasized beyond this upper limit. By adjusting the color reproducibility based on such a photometric value, it is possible to improve the situation in which noise in the image signal becomes noticeable.

(6) Adjustment tendency of color reproducibility based on shutter speed The color reproducibility control section 24 acquires information on the exposure condition from the photographing control section 31. The color reproducibility control unit 24 determines the shutter speed from this exposure condition. FIG. 9 is a diagram showing an adjustment tendency of color reproducibility based on the shutter speed. When the shutter speed is slowed down to some extent during nighttime shooting or the like, noise easily occurs due to long-time exposure. In this case, if the saturation is emphasized excessively, noise in the image signal becomes more noticeable than necessary. Therefore, as shown in FIG. 9, when the shutter speed deviates from the standard range and becomes slow, the color reproducibility control unit 24 sets an upper limit on the saturation emphasis and prevents the saturation from being emphasized beyond this upper limit. To do. By adjusting the color reproducibility based on the shutter speed, it is possible to improve the situation in which the noise of the image signal becomes noticeable.

(7) Color Reproducibility Adjustment Tendency Based on Imaging Sensitivity The color reproducibility control section 24 informs the imaging sensitivity setting of the image sensor 13 (for example, gain setting of the amplifier 14) from the imaging control section 31. get. FIG. 10 is a diagram showing an adjustment tendency of color reproducibility based on the image pickup sensitivity. As the imaging sensitivity becomes higher, the S / N ratio of the image signal becomes worse. In this case, if the saturation is emphasized excessively, noise in the image signal becomes more noticeable than necessary. Therefore, the color reproducibility control unit 24
As shown in FIG. 10, when the image pickup sensitivity is out of the standard range and becomes high, an upper limit is set for the saturation enhancement, and the saturation is not emphasized beyond the upper limit. By adjusting the color reproducibility based on such imaging sensitivity, it is possible to improve the situation in which the noise of the image signal becomes noticeable.

(8) Color reproducibility adjustment tendency based on lens information The color reproducibility control section 24 acquires lens information of the taking lens 12 from the in-lens MPU 12a. This lens information includes the focal length of the taking lens 12, aberration characteristics,
The distance to the focus position and the aperture value at the time of shooting are preferable.
The color reproducibility control unit 24 evaluates and determines the degree of chromatic aberration (axial chromatic aberration, lateral chromatic aberration, etc.) that appears in the image signal based on these pieces of information. FIG. 11 is a diagram showing an adjustment tendency of color reproducibility based on this lens information (chromatic aberration). If the saturation is emphasized excessively under the image pickup condition in which the chromatic aberration is deteriorated, the color shift of the image signal becomes noticeable more than necessary. Therefore, as shown in FIG. 11, the color reproducibility control unit 24 sets an upper limit on the saturation enhancement under the condition that the chromatic aberration deviates from the standard range and deteriorates, so that the saturation is not enhanced more than this upper limit. To do. By adjusting the color reproducibility based on such lens information, it is possible to improve the situation where the color shift of the image signal is noticeable.

(9) Color Reproducibility Adjustment Tendency Based on Illumination Information The color reproducibility controller 24 controls the MPU 30a in the flash device 30.
Get lighting information from. As this lighting information,
The presence or absence of flash light emission, light emission GN (flash light emission amount), and the like are preferable. FIG. 12 shows this illumination information (here, the flash emission amount).
FIG. 7 is a diagram showing a color reproducibility adjustment tendency based on FIG. When the amount of flash light emission increases to a certain extent, the difference in brightness between the places where the illumination is applied and the places where the illumination is not applied is increased. If the saturation is overemphasized in such a situation, there is a high possibility that color saturation will occur in the image signal. Therefore, as shown in FIG. 12, the color reproducibility control unit 24 relatively lowers the saturation adjustment value when the flash light emission amount increases to some extent. For example, it is preferable to lower the adjustment value by one step. By adjusting the color reproducibility based on such illumination information, color saturation can be improved and an image signal with a natural and delicate color tone can be obtained.

[Supplementary Notes on the Embodiment] In the above-mentioned embodiment, the adjustment degree of the color reproducibility is controlled by using a plurality of color-related information such as the photometric value, the saturation and the color concentration. Therefore, even if the saturation emphasis is set to be higher by some of the color-related information, the upper limit of the saturation emphasis is suppressed by another color-related information, and cooperative control is performed.

In this way, by integrating a plurality of color-related information, it is possible to grasp the state of color expression of the image signal in detail and accurately, and to more appropriately control the degree of adjustment of color reproducibility. Become. However, the present invention is not limited to the one using a plurality of color-related information as in the above-described embodiment. Of course, the adjustment degree of color reproducibility may be controlled according to one color-related information.

Further, in such a cooperative control, it is easy to perform the updating of the standard value in order for each color-related information and select the final updated value as the adjustment degree of the color reproducibility. And it is accurate and preferable. Further, regarding the order, it is safe, accurate, and preferable to perform the process of performing the color-related information having a large influence on the color reproducibility later (in particular, as the information that works suppressively). When the order is fixedly implemented, it is preferable that the invention is implemented by referring to the table as in the above-described embodiment because it is simple, quick, and quick.

In the above embodiment, the signal component C
The color reproducibility is adjusted by operating the value of bCr. However, the present invention is not limited to this. In general, any color system (for example, a primary color system, a complementary color system,
In the luminance color difference color system, the Lab color system, the HSB color system, etc.), the signal component relating to the color reproducibility may be manipulated.

In the above embodiment, the case of the electronic camera 11 has been described. However, the present invention is not limited to this. For example, the present invention
It may be realized as a single image processing device separately from the imaging unit (electronic camera, video camera, etc.).

Furthermore, an image processing program (corresponding to claim 12) may be created by program-coding the processing operation relating to the present invention described above. By executing this image processing program, the computer can be made to function as an image processing apparatus. Furthermore, the image processing method as described above can be provided as a service via a communication line such as the Internet.

In the above description, an example of the color-related information has been specifically described in detail. However, the present invention is not limited to these examples of color-related information. The present invention can be implemented in various forms without departing from the spirit or main characteristics shown in the claims.

[0036]

According to the present invention, the color-related information that affects the color expression of the image signal is acquired, and the degree of adjustment of the color reproducibility is controlled according to this color-related information. Therefore, according to the present invention, it is possible to flexibly control the degree of adjustment of the color reproducibility in response to the changing state of the color expression grasped from the color-related information.

By applying the present invention as described above, it is possible to realize a visually natural color expression, such as suppressing excessive saturation enhancement for a special image signal whose color expression is biased. By applying the present invention, it is possible to intentionally realize an unnatural color expression).

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of an electronic camera 11 (including an image processing device).

FIG. 2 is a flowchart illustrating an operation of a color reproducibility control unit 24.

FIG. 3 is a normalized table of color-related information.

FIG. 4 is a diagram showing an adjustment tendency of color reproducibility based on photometric contrast.

FIG. 5 is a diagram showing an adjustment tendency of color reproducibility based on a hue and a degree of color concentration.

FIG. 6 is a diagram showing an adjustment tendency of color reproducibility based on color temperature.

FIG. 7 is a diagram showing an adjustment tendency of color reproducibility based on saturation.

FIG. 8 is a diagram showing an adjustment tendency of color reproducibility based on a photometric value.

FIG. 9 is a diagram showing an adjustment tendency of color reproducibility based on a shutter speed.

FIG. 10 is a diagram showing an adjustment tendency of color reproducibility based on imaging sensitivity.

FIG. 11 is a diagram showing an adjustment tendency of color reproducibility based on lens information.

FIG. 12 is a diagram showing an adjustment tendency of color reproducibility based on illumination information.

[Explanation of symbols]

11 electronic camera 12 Shooting lens 12a MPU in lens 13 Image sensor 14 amplifier 16 A / D converter 17 White balance processing section 17a Color distribution evaluation unit 18 Interpolation processing unit 19 Noise suppression unit 20 Gamma converter 21 Matrix converter 22 Contour adjustment section 23 Color noise suppressor 24 color reproduction control unit 25 Luminance distribution evaluation unit 29 split photometric sensor 30 flash device 30a Flash unit MPU 31 Shooting control unit

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Claims (13)

[Claims] 1. An image processing apparatus for processing an image signal generated by an image pickup section, comprising: a color reproducibility adjusting section that adjusts color reproducibility of the image signal by varying at least saturation. An image processing apparatus, comprising: a color reproducibility control unit that acquires color related information that influences the color expression of, and controls the degree of adjustment of the color reproducibility according to the color related information. 2. The image processing apparatus according to claim 1, wherein at least one of the color-related information is an image pickup condition of the image signal, and the color reproducibility control unit sets the image pickup condition of the image signal. An image processing apparatus, which acquires information and controls the degree of adjustment of the color reproducibility according to the imaging conditions. 3. The image processing apparatus according to claim 1, wherein at least one of the color-related information is an analysis result of the image signal, and the color reproducibility control unit displays the analysis result of the image signal. An image processing apparatus, which acquires information and controls the degree of adjustment of the color reproducibility according to the analysis result. 4. The image processing apparatus according to claim 2, wherein at least one of the imaging conditions is a photometric value of a field, and the color reproducibility control unit is configured to capture the image signal. An image processing apparatus, which acquires information on the photometric value and controls the adjustment degree of the color reproducibility according to the photometric value. 5. The image processing apparatus according to claim 2, wherein at least one of the image capturing conditions is a divided photometric value of a field, and the color reproducibility control unit captures the image signal. 2. The image processing apparatus, wherein information of the divided photometric value is acquired, and the degree of adjustment of the color reproducibility is controlled according to the photometric contrast obtained from the divided photometric value. 6. The image processing apparatus according to claim 2, wherein at least one of the image capturing conditions is illumination information regarding subject illumination, and the color reproducibility control unit is the image capturing device when capturing the image signal. An image processing apparatus, which acquires illumination information and controls the adjustment degree of the color reproducibility according to the illumination information. 7. The image processing apparatus according to claim 2, wherein at least one of the image pickup conditions is an exposure condition of the image pickup unit, and the color reproducibility control unit sets the image signal when the image signal is picked up. An image processing apparatus, which acquires information on the exposure condition and controls the adjustment degree of the color reproducibility according to the exposure condition. 8. The image processing apparatus according to claim 2, wherein at least one of the image capturing conditions is lens information regarding a lens of the image capturing unit, and the color reproducibility control unit captures the image signal. An image processing apparatus, which acquires the lens information at that time and controls the adjustment degree of the color reproducibility according to the lens information. 9. The image processing apparatus according to claim 2, wherein at least one of the image pickup conditions is image pickup sensitivity of the image pickup unit, and the color reproducibility control unit sets the image signal when the image signal is picked up. An image processing apparatus, which acquires information on the image pickup sensitivity and controls the degree of adjustment of the color reproducibility according to the image pickup sensitivity. 10. The image processing apparatus according to claim 3, wherein at least one of the analysis results is color information regarding a color of the image signal, and the color reproducibility control unit includes the color of the image signal. An image processing apparatus, which acquires information and controls an adjustment degree of the color reproducibility according to the color information. 11. The image processing apparatus according to claim 3, wherein at least one of the analysis results is a color concentration degree indicating a screen occupation degree of color in the image signal, and the color reproducibility control unit is An image processing apparatus, characterized in that information on the degree of color concentration of the image signal is acquired and the degree of adjustment of the color reproducibility is controlled according to the degree of color concentration. 12. An image processing program that causes a computer to function as the color reproducibility adjusting unit and the color reproducibility control unit according to claim 1. Description: 13. An image processing method for performing image processing on an image signal generated by an image pickup unit, comprising obtaining information on "color-related information affecting color expression" for the image signal, and responding to the color-related information according to the color-related information. Determining the adjustment degree of color reproducibility, and adjusting at least the saturation according to the adjustment degree to adjust the color reproducibility of the image signal.