Patent ID: 9406005
Filing Date: 2016-08-02
CPC Classification: B41J,G03G,G06K,H04N

Claim Text:
1. A gamma correction table generation method of measuring a density patch output by an image forming device and including a predetermined unit pattern composed of a plurality of pixels, the gamma correction table generation method comprising: obtaining density information corresponding to the density patch by reading, with a reading sensor, the density patch, wherein the unit pattern is composed of halftone pixels representing a target tone as a pixel unit and white pixels, wherein the halftone pixels is a part of a line in the unit pattern, wherein the density patch is an image in which a plurality of same unit patterns is arranged like a tile in parallel to a line included in each unit pattern, and wherein the unit pattern included in the density patch includes white pixels at least at one of positions adjacent to the halftone pixels such that a width of a line formed by the halftone pixels included in the unit pattern is maintained; correcting the density information based on a ratio of a number of halftone pixels to a number of pixels included in the unit pattern; and generating a gamma correction table based on the corrected density information.