Patent ID: 6965406
Filing Date: 2005-11-15
Classification: H04N

Abstract:
1. An image processor for compensating gradation of image data, comprising: domain judging means for judging a domain to which said image data belongs in order to output the result of judgment; coefficient calculating means for outputting a compensation coefficient to compensate a pixel value of said image data based on said result of judgment; and compensating means for compensating a pixel value of said image data depending on said compensation coefficient, wherein said domain judging means includes a plurality of low-pass filters respectively extracting low frequency elements of said image data and signal combining means for generating a combining signal of 1 based on the low frequency element output from a plurality of said low-pass filters and said coefficient calculating means generates said compensation coefficient based on said combining signal, wherein each of said plurality of said low pass filters has a weighing coefficient wherein the sum of the weighing coefficients for said plurality of said low pass filters equals one.