IMAGE PROCESSING UNIT AND IMAGE PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an image processing unit and an image processing method that can attain excellent pseudo medium tone processing without the need for switching a threshold value matrix pattern. SOLUTION: A density fluctuation period detection section 51 detects a density fluctuation period (number of dot lines) of an image of a processing object. A fluctuation threshold value matrix memory 53 stores a fluctuation threshold value matrix that is periodically fluctuated for a prescribed period in a two-dimensional direction. When the density fluctuation period of an image of a processing object is close to a fluctuation period of a fluctuation threshold value in the fluctuation threshold value matrix, a matrix read control section 52 revises a read sequence of the fluctuation threshold value from the fluctuation threshold value matrix memory 53. Thus, the fluctuation threshold value matrix can substantially be modified.