Image processing device, image processing method, and image processing program

Abstract

A CPU 200 acquires image data of a photographed image, determines a specific subject area containing a specific subject in the photographed image, and calculates a specific subject characteristic value for representing a characteristic of image data corresponding to the determined specific subject area. CPU 200 calculates a correction value for color balance correction using the calculated specific subject characteristic value and a preset characteristic target value, and executes the color balance correction on the image data using the calculated correction value

1 . An image processing device for executing color balance correction on image data of a photographed image, said image processing device comprising:
 an image data acquisition module that acquires said image data;   a specific subject area determination module that determines a specific subject area in said photographed image, wherein said specific subject area contains a specific subject in said photographed image;   a specific subject characteristic value calculation module that calculates a specific subject characteristic value, wherein said specific subject characteristic value represents a characteristic of image data corresponding to said determined specific subject area;   a correction value calculation module that calculate a correction value for color balance correction using said calculated specific subject characteristic value and a preset characteristic target value; and   a correction execution module that execute said color balance correction on said image data using said calculated correction value.   
   
   
       2 . An image processing device according to  claim 1 , wherein
 said specific subject characteristic value calculation is executed using weighted distribution, wherein said weighted distribution is set so as to be a weight in a center area of said specific subject area larger than a weight in an area outside said center area.   
   
   
       3 . An image processing device according to  claim 1 , wherein
 when a plurality of said specific subject areas are determined,   said specific subject characteristic value calculation is executed using weighted distribution, wherein said weighted distribution is set according to a size of each specific subject area on each specific subject characteristic value of said plurality of specific subject areas.   
   
   
       4 . An image processing device according to  claim 3 , wherein
 said specific subject characteristic value calculation is executed by obtaining a weighted average value of said specific subject characteristic value of said plurality of specific subject areas.   
   
   
       5 . An image processing device according to  claim 1 , wherein
 said specific subject characteristic value includes a characteristic value relating to a hue of said specific subject.   
   
   
       6 . An image processing device according to  claim 1 , wherein
 said specific subject characteristic value includes a specific color characteristic value for representing a characteristic of pixel data included within said specific subject area, said pixel data belonging to a specific color range.   
   
   
       7 . An image processing device according to  claim 6 , wherein
 said specific color characteristic value includes a statistical value of pixel values of said pixel data belonging to said specific color range,   wherein said characteristic target value includes a preset pixel target value, and   wherein said calculated correction value includes a correction value for eliminating or reducing a difference between said statistical value of pixel values and said pixel target value.   
   
   
       8 . An image processing device according to  claim 6 , wherein
 said specific subject includes a face part of a human subject, and   wherein said pixel data belonging to said specific color range includes flesh colored pixel data belonging to a color range corresponding to a flesh color of said human subject.   
   
   
       9 . An image processing device according to  claim 1 , wherein
 said calculated correction value includes a correction value weighted according to an area ratio of said specific subject area to a whole area of said photographed image.   
   
   
       10 . An image processing device according to  claim 1 , wherein
 said correction execution module executes said color balance correction using said calculated correction value when an area ratio of said specific subject area to a whole area of said photographed image is greater than a reference value.   
   
   
       11 . An image processing device according to  claim 1 , wherein
 said specific subject determination module determines said specific subject area using pixel values of pixel data included in a target area for determination, and a position of said target area in said photographed image.   
   
   
       12 . An image processing method for executing color balance correction on image data of a photographed image, said image processing method comprising:
 acquiring said image data;   determining a specific subject area in said photographed image, wherein said specific subject area contains a specific subject in said photographed image;   calculating a specific subject characteristic value, wherein said specific subject characteristic value represents a characteristic of image data corresponding to said determined specific subject area;   calculating a correction value for color balance correction using said calculated specific subject characteristic value and a preset characteristic target value; and   executing said color balance correction on said image data using said calculated correction value.   
   
   
       13 . An image processing method according to  claim 12 , wherein
 said calculating said specific subject characteristic value is executed using weighted distribution, wherein said weighted distribution is set so as to be a weight in a center area of said specific subject area larger than a weight in an area outside said center area.   
   
   
       14 . An image processing method according to  claim 12 , wherein
 when a plurality of said specific subject areas are determined,   said calculating said specific subject characteristic value is executed using weighted distribution, wherein said weighted distribution is set according to a size of each specific subject area on each specific subject characteristic value of said plurality of specific subject areas.   
   
   
       15 . An image processing method according to  claim 12 , wherein
 said specific subject characteristic value includes a specific color characteristic value for representing a characteristic of pixel data included within said specific subject area, said pixel data belonging to a specific color range.   
   
   
       16 . An image processing method according to  claim 15 , wherein
 said specific color characteristic value includes a statistical value of pixel values of said pixel data belonging to said specific color range,   wherein said characteristic target value includes a preset pixel target value, and   wherein said calculated correction value includes a correction value for eliminating or reducing a difference between said statistical value of pixel values and said pixel target value.   
   
   
       17 . An image processing method according to  claim 15 , wherein
 said specific subject includes a face part of a human subject, and   wherein said pixel data belonging to said specific color range includes flesh colored pixel data belonging to a color range corresponding to a flesh color of said human subject.   
   
   
       18 . An image processing method according to  claim 12 , wherein
 said calculated correction value includes a correction value weighted according to an area ratio of said specific subject area to a whole area of said photographed image.   
   
   
       19 . An image processing method according to  claim 12 , wherein
 said executing said color balance correction using said calculated correction value when an area ratio of said specific subject area to a whole area of said photographed image is greater than a reference value.   
   
   
       20 . A computer program product for executing color balance correction on image data of a photographed image, said computer program product comprising:
 a computer readable medium; and   a computer program stored on said computer readable medium, said computer program comprising:   a program instruction for acquiring said image data;   a program instruction for determining a specific subject area in said photographed image, wherein said specific subject area contains a specific subject in said photographed image;   a program instruction for calculating a specific subject characteristic value, wherein said specific subject characteristic value represents a characteristic of image data corresponding to said determined specific subject area;   a program instruction for calculating a correction value for color balance correction using said calculated specific subject characteristic value and a preset characteristic target value; and   a program instruction for executing said color balance correction on said image data using said calculated correction value