Patent ID: 6259472
Filing Date: 2001-07-10
Classification: G06T

Abstract:
A histogram equalization apparatus for a image expressed by a predetermined number of gray levels, comprising:a calculator for counting the number of pixels having a gray level from the minimum to the maximum or less with respect to an input image in a screen unit to calculate cumulative distribution function (CDF) values of each gray level; anda memory for updating histogram-equalized levels corresponding to each gray level of the input image in a screen unit based on the CDF value of each gray level of a previous screen unit, and outputting a corresponding histogram-equalized level according to a level of the input image;wherein the calculator comprises:a plurality of comparators for comparing whether the level of the input image is less than or equal to each gray level; anda plurality of accumulators for accumulating each output of the plurality of comparators to output the CDF values of each gray level from the minimum to the maximum or less per one screen unit.