Patent ID: 8233038
Filing Date: 2012-07-31
Classification: A61B,G06T,H04N

Abstract:
1. An image-signal processing unit comprising: a receiver that receives an image signal, said image signal comprising a plurality of pixel signals, each pixel signal being generated according to an amount of light received by a pixel, a plurality of pixels being arranged on a light-receiving surface of an imaging device; a first luminance calculator that calculates a first luminance corresponding to the sum of a plurality of primary color light components, each multiplied by a coefficient from a first coefficient combination, for each of said pixels, based on said image signal, the first luminance being a wide band luminance signal calculated based upon color signal components corresponding to complementary color filter elements Mg, Cy, Ye and G; a second luminance calculator that calculates a second luminance corresponding to the sum of a plurality of said primary color light components, each multiplied by a coefficient from a second coefficient combination, for each of said pixels, based on said image signal, wherein a ratio of the coefficient by which a first primary color light component is multiplied, to the coefficient by which a second primary color light component is multiplied, is greater than the ratio in said first coefficient combination, the second luminance being a narrow band luminance signal calculated based upon primary color signals R, G, and B the primary color signals being calculated based upon color signal components corresponding to the complementary color filter elements; a comparator that compares said first luminance with a threshold value; a correction-value calculator that calculates a luminance correction value according to said second luminance when said first luminance is greater than said threshold value; and a subtractor that calculates a corrected luminance by subtracting said luminance correction value from said first luminance.