Patent ID: 6768514
Filing Date: 2004-07-27
Classification: H04N

Abstract:
An image processing apparatus for correcting the gradation of image data comprising:an area judgement means for outputting a judgement result in judging an area to which said image data belong, said area judgment means including low-pass filters of more than three units outputting band-limited-signals in limiting the bandwidth of said image data by different passbands from each other, and a signal composition means for outputting said judgment result in composing said band-limited-signals, said signal composition means for generating said one judgment signal in composing said band-limited-signals output from said low-pass filters in order starting from the term having the lowest value of the resolution or from the term having the highest value of the resolution, a coefficient calculation means for outputting a correction coefficient for correcting pixel values in said image data based on said judgement result, and a correction means for correcting pixel values in said image data according to said correction coefficient, said area judgement means being arranged to increase the resolution of said image data with the approach to an edge in an image formed by said judgment result.