Image processing apparatus, image processing method, storage medium and program

摘要

A first unit obtains a gradation conversion characteristic for equalizing a histogram of an input image. A second unit obtains an inverse characteristic of a gradation conversion characteristic for equalizing a histogram of an image to which a predetermined gradation conversion is applied. A third unit composites the gradation conversion characteristic obtained by the first unit and the inverse characteristic obtained by the second unit. A fourth unit performs fitting on the composited characteristic obtained by the third unit with a lower degree function. Gradation of the input image is converted based on the composited characteristic after the processing by the fourth unit.