ADAPTIVE QUANTIZATION METHOD, ADAPTIVE QUANTIZATION APPARATUS AND ADAPTIVE QUANTIZATION PROGRAM

摘要

PROBLEM TO BE SOLVED: To establish a quantization method with which a conversion error which may occur when performing a gradation conversion on an image signal is minimized.

SOLUTION: When approximating a histogram of input signals with the number of classes given separately, an approximate error calculation section 14 stores in a memory a quantization value minimizing an approximate error for all candidates of a class boundary and a minimum value of the approximate error at that time, and when selecting a class boundary in the next class, reads the stored minimum value from the memory to use it for calculating the approximate error in the class boundary selection at that point in time. A block upper-end optimal value tracking section 17 selects such a class boundary as to minimize the approximate error for all the candidates of the class boundary from a result calculated by the approximate error calculation section 14.

COPYRIGHT: (C)2012,JPO&INPIT