Patent ID: 7705892
Filing Date: 2010-04-27
Classification: H04N

Abstract:
1. An auto white balance apparatus comprising: block-dividing means for dividing an input image into a plurality of blocks; typical-value calculating means for calculating, for every block, a typical value including luminance and color difference representing a block in accordance with each color value in the block; characteristic pixel determination means for determining, for every block, a characteristic pixel from a pixel group constituting the block; light-source reflection determination means for determining, for every block, whether the typical value of the block reflects a light source of the input image, by comparing a typical color difference of the block with a color difference of a characteristic pixel of the block; white balance evaluating means for estimating the color of the light source of the input image in accordance with the typical luminance and the typical color difference of the block for which the light-source reflection determination means determines that the block reflects the light source and the object luminance of the input image; white balance gain calculating means for calculating a white balance gain to be applied to the input image in accordance with the estimated light-source color; white balance adjusting means for adjusting the white balance to the input image by use of the calculated white balance gain; and the characteristic pixel determination means determines as a characteristic pixel of the block a pixel having the highest luminance from among a pixel group constituting the block.