In order dot size decisive manner, the dot size decision program and its record media, and

摘要

PROBLEM TO BE SOLVED: To provide a method of determining a dot size for deriving an optimum dot size that allows to prevent deterioration of image quality in a value reduction processing based on a dot size modulating method. SOLUTION: In the value reduction processing, gradation representation is executed by using a plurality of sizes of dots in order to reproduce, by a lower information level, image data input by multi-values. The size of the dot is determined to be an optimum dot size in consideration of a brightness and a granularity, and a combination of dot sizes is determined such that the variation of the granularity is minimized.