| 摘要 |
An auto white balancing apparatus includes a block split circuit for splitting an image into a plurality of blocks; a representative color calculating circuit which for each split block, derives a representative color of each block on the basis of pixel values within each block; and a block reliability estimating circuit which for each block and for each light source determines the distance between color difference components of the color of a white object under each light source and color difference components of the representative color of each block, to thereby estimate a reliability signal with which each light source lights a scene of each block on the basis of the distances. The auto white balancing apparatus also includes a light source contribution component estimating circuit which for each light source, weights and averages the representative color of each block in accordance with the reliability signal of each light source upon each block, to thereby estimate components of contribution of each light source to the entire image; and a total reliability estimating circuit which for each light source, totals up the reliability signal of each light source upon each block over all blocks contained within the image, to thereby estimate the reliability signal of each light source in the entire image. The auto white balancing apparatus further includes a lighting color estimating circuit for weighting and averaging components of contribution of each light source to the entire image estimated by the light source contribution component estimating circuit, in accordance with the reliability signal of each light source upon the entire image estimated by the total reliability estimating circuit, to thereby estimate the color of lighting which lights the scene of the entire image; and a white balancing circuit for executing white balance processing of each pixel of the image so as to cancel the lighting color estimated.
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