Image signal processing device, digital camera and computer program product for processing image signal

A computer-readable computer program product having a program to be used to process an image signal constituting a subject image captured at an image-capturing element, with the program comprising:

• average calculation processing in which pixel output averages are calculated for individual colors in each of a plurality of partition areas into which a light-receiving surface of the image-capturing element is divided based upon the image signal;
• average ratio calculation processing in which a ratio of the pixel output average corresponding to another color to the pixel output average corresponding to a reference color is calculated for each partition area;
• area extraction processing in which any area having a ratio of pixel output averages within a predetermined range is extracted from the plurality of partition areas;
• and
• white balance adjustment processing in which white balance adjustment is performed based upon pixel outputs corresponding to the individual colors from the extracted area.

An image signal processing device that processes an image signal constituting a subject image captured by an image-capturing element comprising:

• a saturation calculating unit that calculates a saturation level in each of a plurality of partition areas based upon pixel outputs from the partition areas into which a light-receiving surface of the image-capturing element is divided;
• an area extracting unit that extracts any area having a saturation level within a predetermined range from the plurality of partition areas;
• and
• a white balance adjustment unit that performs a white balance adjustment based upon pixel outputs corresponding to individual colors from the extracted area.

A computer-readable computer program product having a program to be used to process an image signal constituting a subject image captured at an image-capturing element, with the program comprising:

• saturation calculation processing in which a saturation level in each of a plurality of partition areas is calculated based upon pixel outputs from the partition areas into which a light-receiving surface of the image-capturing element is divided;
• area extraction processing in which any area having a saturation level within a predetermined range is extracted from the plurality of partition areas;
• and
• white balance adjustment processing in which white balance adjustment is performed based upon pixel outputs corresponding to individual colors from the extracted area.