Patent ID: 8411338

Claim:
A chromatism correction apparatus for correcting a chromatism occurring in image data picked up by an image pickup device through an optical system, the apparatus comprising: first determining means for determining whether a specified one of pixels in an image based on the image data has a luminance value below a first predetermined luminance threshold; first calculating means for calculating a distance between the center of the image and the specified pixel; confirm pixel setting means for automatically selecting and setting a plurality of confirm pixels between the specified pixel and a center of the image in a first direction along a straight line passing through the specified pixel and the center of the image, the confirm pixels being automatically selected and set based on the distance between the center of the image and the specified pixel calculated by the first calculating means and regardless of a luminance value of said confirm pixels; second determining means for determining whether there is a particular confirm pixel having a luminance value higher than a second predetermined luminance threshold from among the plurality of confirm pixels set by the confirm pixel setting means, wherein the second predetermined luminance threshold is higher than the first predetermined luminance threshold; reference pixel setting means for automatically setting a pixel as a reference pixel on the image, the reference pixel being set with respect to the specified pixel in a second direction opposite the first direction along the straight line passing through the specified pixel and the center of the image, wherein a distance between the reference pixel and the specified pixel is set based on (i) a characteristic of a chromatism of the optical system and (ii) the distance between the center of the image and the specified pixel calculated by the first calculating means; and converting means for converting a pixel value of a predetermined color component of the specified pixel to a different pixel value based on a pixel value of a same color component of the reference pixel, only when the second determining means determines that the particular confirm pixel having the luminance value higher than the second predetermined luminance threshold exists.