Multi-area white-balance control device, multi-area white-balance control method, multi-area white-balance control program, computer in which multi-area white-balance control program is recorded, multi-area white-balance image-processing device, multi-area white-balance image-processing method, multi-area white-balance image-processing program, computer in which multi-area white-balance image-processing program is recorded, and image-capture apparatus
A multi-area white-balance control device includes a component that divides an inputted image into a plurality of division areas, a component that estimates a lighting-source color temperature for each division area, a component that calculates out color information of an areal image for each division area, and a component that acquires information for white-balance processing on the basis of the lighting-source color temperature and the color information of the areal image for each division in such a manner as to weight, in the information for white-balance processing, a multi-area white-balance factor as more significant in reference to a single-area white-balance factor in a case where the color information has a value higher than a predetermined value, than in a case where the color information fails to have the predetermined value. Thereby, an image with natural color reproduction can be generated.
1. A multi-area white-balance control device comprising:
an area divider that divides an inputted image into a plurality of division areas;
a lighting-source color-temperature estimator that estimates a lighting-source color temperature in each of the division areas;
an areal-image color-information calculator that calculates out color information of an areal image for each of the division areas; and
a white-balance controller that acquires information for white-balance processing for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated by the lighting-source color-temperature estimator and the color information of the areal image for each of the division areas calculated out by the areal-image color-information calculator;
wherein, in acquiring the information for white-balance processing for each of the division areas, the white-balance controller considers at least one of a multi-area white-balance factor and a single-area white-balance factor in such a manner that the multi-area white-balance factor is weighted as more significant in a case where the color information of the areal image for each of the division areas has a value higher than a predetermined value, than in a case where the color information of the areal image for each of the division areas fails to have a value higher than the predetermined value.
2. The multi-area white-balance control device according to claim 1 ,
wherein the information for white-balance processing for each of the division areas includes a white-balance coefficient for each of the division areas,
wherein the white-balance controller comprises:
a multi-area white-balance coefficient generator that generates a multi-area white-balance coefficient for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated by the lighting-source color-temperature estimator;
a single-area white-balance coefficient generator that generates a single-area white-balance coefficient; and
a white-balance coefficient synthesizer that calculates out the white-balance coefficient for each of the division areas by synthesizing the multi-area white-balance coefficient for each of the division areas and the single-area white-balance coefficient, and
wherein, in calculating out the white-balance coefficient for each of the division areas, the white-balance coefficient synthesizer synthesizes the multi-area white-balance coefficient for each of the division areas and the single-area white-balance coefficient in such a manner that a component ratio of the multi-area white-balance coefficient increases according as a value of the color information of the areal image for each of the division areas increases.
3. The multi-area white-balance control device according to claim 2 , wherein the color information of the areal image for each of the division areas includes saturation information.
4. A multi-area white-balance image-processing device comprising:
the multi-area white-balance control device according to claim 2 ; and
a white-balance processor that performs white-balance processing for the entirety of the inputted image, which is subject to division by the area divider, on a basis of the information for white-balance processing in the individual division areas acquired by the white-balance controller provided in the multi-area white-balance control device.
5. The multi-area white-balance control device according to claim 1 ,
wherein the information for white-balance processing for each of the division areas includes a white-balance coefficient for each of the division areas,
wherein the lighting-source color-temperature estimator further estimates a lighting-source color temperature in a single area as an entirety of the inputted image, on a basis of the lighting-source color temperatures in the individual division areas as estimated,
wherein the white-balance controller comprises:
a color-temperature synthesizer that synthesizes the lighting-source color temperature in each of the division areas and the lighting-source color temperature in the single area estimated by the lighting-source color-temperature estimator, to calculate out an adjusted lighting-source color temperature in each of the division areas; and
a white-balance coefficient generator that generates the white-balance coefficient for each of the division areas on a basis of the adjusted lighting-source color temperature in each of the division areas calculated out by the color-temperature synthesizer; and
wherein, in calculating out the adjusted lighting-source color temperature in each of the division areas, the color-temperature synthesizer synthesizes the lighting-source color temperature in each of the division areas and the lighting-source color temperature in the single area estimated by the lighting-source color-temperature estimator in such a manner that a component ratio of the lighting-source color-temperature in each of the division areas estimated by the lighting-source color-temperature estimator increases according as a value of the color information of the areal image for each of the division areas calculated out by the areal-image color-information calculator increases.
6. The multi-area white-balance control device according to claim 5 , wherein the color information of the areal image for each of the division areas includes saturation information.
7. A multi-area white-balance image-processing device comprising:
the multi-area white-balance control device according to claim 5 ; and
a white-balance processor that performs white-balance processing for the entirety of the inputted image, which is subject to division by the area divider, on a basis of the information for white-balance processing in the individual division areas acquired by the white-balance controller provided in the multi-area white-balance control device.
8. The multi-area white-balance control device according to claim 1 ,
wherein the information for white-balance processing for each of the division areas includes a white-balance gain map for each of the division areas,
wherein the white-balance controller comprises:
a multi-area white-balance gain map generator that generates a multi-area white-balance gain map for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated by the lighting-source color-temperature estimator;
a single-area white-balance gain map generator that generates a single-area white-balance gain map; and
a white-balance gain map synthesizer that calculates out the white-balance gain map for each of the division areas by synthesizing the multi-area white-balance gain map for each of the division areas and the single-area white-balance gain map, and
wherein, in calculating out the white-balance gain map for each of the division areas, the white-balance gain map synthesizer synthesizes the multi-area white-balance gain map for each of the division areas and the single-area white-balance gain map in such a manner that a component ratio of the multi-area white-balance gain map increases according as a value of the color information of the areal image for each of the division areas increases.
9. The multi-area white-balance control device according to claim 8 , wherein the color information of the areal image for each of the division areas includes saturation information.
10. A multi-area white-balance image-processing device comprising:
the multi-area white-balance control device according to claim 8 ; and
a white-balance processor that performs white-balance processing for the entirety of the inputted image, which is subject to division by the area divider, on a basis of the information for white-balance processing in the individual division areas acquired by the white-balance controller provided in the multi-area white-balance control device.
11. The multi-area white-balance control device according to claim 1 ,
wherein the information for white-balance processing for each of the division areas includes a white-balance gain map for each of the division areas,
wherein the lighting-source color-temperature estimator further estimates a lighting-source color temperature in a single area as an entirety of the inputted image, on a basis of the lighting-source color temperatures in the individual division areas as estimated,
wherein the white-balance controller comprises:
a color-temperature synthesizer that synthesizes the lighting-source color temperature in each of the division areas and the lighting-source color temperature in the single area estimated by the lighting-source color-temperature estimator, to calculate out an adjusted lighting-source color temperature in each of the division areas; and
a white-balance gain map generator that generates the white-balance gain map for each of the division areas on a basis of the adjusted lighting-source color temperature in each of the division areas calculated out by the color-temperature synthesizer; and
wherein, in calculating out the adjusted lighting-source color temperature in each of the division areas, the color-temperature synthesizer synthesizes the lighting-source color temperature in each of the division areas and the lighting-source color temperature in the single area estimated by the lighting-source color-temperature estimator in such a manner that a component ratio of the lighting-source color-temperature in each of the division areas estimated by the lighting-source color-temperature estimator increases according as a value of the color information of the areal image for each of the division areas calculated out by the areal-image color-information calculator increases.
12. The multi-area white-balance control device according to claim 11 , wherein the color information of the areal image for each of the division areas includes saturation information.
13. A multi-area white-balance image-processing device comprising:
the multi-area white-balance control device according to claim 11 ; and
a white-balance processor that performs white-balance processing for the entirety of the inputted image, which is subject to division by the area divider, on a basis of the information for white-balance processing in the individual division areas acquired by the white-balance controller provided in the multi-area white-balance control device.
14. The multi-area white-balance control device according to claim 1 , wherein the color information of the areal image for each of the division areas includes saturation information.
15. A multi-area white-balance image-processing device comprising:
the multi-area white-balance control device according to claim 1 ; and
a white-balance processor that performs white-balance processing for the entirety of the inputted image, which is subject to division by the area divider, on a basis of the information for white-balance processing in the individual division areas acquired by the white-balance controller provided in the multi-area white-balance control device.
16. An image capture apparatus provided with the multi-area white-balance image-processing device according to claim 15 .
17. A multi-area white-balance control method comprising:
dividing an inputted image into a plurality of division areas;
estimating a lighting-source color temperature in each of the division areas;
calculating out color information of an areal image for each of the division areas; and
acquiring information for white-balance processing for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated and the color information of the areal image for each of the division areas calculated out;
wherein acquisition of the information for white-balance processing for each of the division areas includes considering at least one of a multi-area white-balance factor and a single-area white-balance factor in such a manner that the multi-area white-balance factor is weighted as more significant in a case where the color information of the areal image for each of the division areas has a value higher than a predetermined value, than in a case where the color information of the areal image for each of the division areas fails to have a value higher than the predetermined value.
18. A computer which is provided in a multi-area white-balance control device and in which a multi-area white-balance control program is recorded,
wherein the multi-area white-balance control program is configured to make the computer function as:
an area divider that divides an inputted image into a plurality of division areas;
a lighting-source color-temperature estimator that estimates a lighting-source color temperature in each of the division areas;
an areal-image color-information calculator that calculates out color information of an areal image for each of the division areas; and
a white-balance controller that acquires information for white-balance processing for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated by the lighting-source color-temperature estimator and the color information of the areal image for each of the division areas calculated out by the areal-image color-information calculator; and
wherein, in acquiring the information for white-balance processing for each of the division areas, the white-balance controller considers at least one of a multi-area white-balance factor and a single-area white-balance factor in such a manner that the multi-area white-balance factor is weighted as more significant in a case where the color information of the areal image for each of the division areas has a value higher than a predetermined value, than in a case where the color information of the areal image for each of the division areas fails to have a value higher than the predetermined value.
19. A multi-area white-balance control program which is provided on a non-transitory computer readable medium, and which is readable by a computer provided in a multi-area white-balance control device,
wherein the multi-area white-balance control program is configured to make the computer function as:
an area divider that divides an inputted image into a plurality of division areas;
a lighting-source color-temperature estimator that estimates a lighting-source color temperature in each of the division areas;
an areal-image color-information calculator that calculates out color information of an areal image for each of the division areas; and
a white-balance controller that acquires information for white-balance processing for each of the division areas on a basis of the lighting-source color temperature in each of the division areas estimated by the lighting-source color-temperature estimator and the color information of the areal image for each of the division areas calculated out by the areal-image color-information calculator; and
wherein, in acquiring the information for white-balance processing for each of the division areas, the white-balance controller considers at least one of a multi-area white-balance factor and a single-area white-balance factor in such a manner that the multi-area white-balance factor is weighted as more significant in a case where the color information of the areal image for each of the division areas has a value higher than a predetermined value, than in a case where the color information of the areal image for each of the division areas fails to have a value higher than the predetermined value.