1. An image processing method including a step of dynamic-range-compression processing of an image, wherein said dynamic-range compression processing step comprises: a sorting step of sorting said image into a first and a second sites; an extraction step of extracting the characteristic amounts of at least two pixels contained in at least either said first or second site; a statistical-amount acquisition step of determining the statistical amount of said characteristic amounts for at least either said first or second site; and a transformation step of transforming pixel values based on said statistical amount.