IMAGE PROCESSING UNIT, IMAGE PROCESSING METHOD AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an image processing technology by which a binary image with high resolution is easily printed out even with an exposure means with a low resolution. SOLUTION: A matrix acquisition section 22 changes a high resolution binary image into an array consisting of pluralities of pixel groups each consisting of 2×2 pixels of the binary image and each of pluralities of the pixel groups is shifted by one pixel each longitudinally and laterally to obtain two matrices. Then an exposure image acquisition section 21 uses each of a pixel group being a component of the matrix as a unit pixel and the sum of the density of four pixels included in each of the pixel groups is selected for a density of the unit pixel corresponding to the pixel group to obtain two multi-value exposure image expressed in a resolution of a half of the binary image. Then an optical unit 60 calibrates the exposure luminous quantity to apply multiple exposure to each of the two multi-value exposure images.