IMAGE PROCESSING UNIT, METHOD FOR THE UNIT AND STORAGE MEDIUM STORING THE METHOD

摘要

PROBLEM TO BE SOLVED: To attain efficient coding even with respect to image data having discrete picture element values by revising coded data corresponding to a predicted error so as to conduct entropy coding. SOLUTION: A conversion table update circuit 107 is operated when a control signal from a signal line 113 is logical 1 to rewrite a conversion table 111. Thus, the conversion table 111 is rewritten so that a prediction error with a high frequency of incidence is concentrated onto a value close to a zero intermediate output being a short code length. When a discrimination circuit 112 discriminates an image to be a specific image, a value with a large absolute value is assigned to a prediction error never generated. As a result, entropy coding with a high efficiency is conducted.