DYNAMIC RANGE COMPRESSION PROCESSING METHOD FOR IMAGE

摘要

PURPOSE:To properly compress a dynamic range by the dynamic range compression processing method which obtains a processed image signal by compressing the dynamic range of an image signal of the original image even when the contrast of the original image is different from the contrast of a normal image. CONSTITUTION:The defocusing mask signal Sus of the original image signal Sorg is found and monotonous decrease functions f1(Sus) and f2(Sus) including the value of the defocusing mask signal Sus as variables are used to obtain the processed image signal Sproc carrying an image having a narrower dynamic range than the original image signal Sorg according to Sproc=Sorg+f1,2(Sus). At this time, the application signal ranges and/or values of the functions f1(Sus) and f2(Sus) are varied like functions f1' and f2' or functions f1'' and f2'' according to whether the contrast of the original image signal Sorg is high or low.