IMAGE PROCESSING DEVICE, IMAGE FORMATION APPARATUS, IMAGE PROCESSING METHOD AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To solve a problem in which it is difficult to suppress an influence of sub-scanning unevenness in which a plurality of pieces of periodicity exist in a method of calculating a representative density value of each gradation for each main-scanning position of a gradation correction table.SOLUTION: An image formation apparatus of generating a correction table for density correction to cancel an influence of density unevenness occurring in image formation to an input image comprises: patch image generation means which generates data of a patch image arranged so that patches with the same gradation appear plural times in the sub-scanning direction by a unit of a first region extending in the sub-scanning direction sectioned in the main-scanning direction and; representative density value derivation means which derives a representative density value of the patches with each gradation by a unit of a second region extending in the sub-scanning direction sectioned in the main-scanning direction from a scan image obtained by reading a chart printed with the patch image; and correction table generation means which generates a correction table for density correction corresponding to each main-scanning position of the second region on the basis of the derived representative density value of the patches with each gradation.SELECTED DRAWING: Figure 9