Patent ID: 9522543
Filing Date: 2016-12-20
CPC Classification: B41J,H04N

Claim Text:
1. An image processing method comprising: a density unevenness measurement image formation step of forming an image for density unevenness measurement on a recording medium in a single-pass method, using an inkjet head in which nozzles are disposed in a main scanning direction, based on image data on which unevenness correction processing is performed using a preset unevenness correction value, and performing defect correction on the image data using a correction nozzle adjacent to a defective nozzle; a density measurement value acquisition step of acquiring a density measurement value for each of one or more set gradation values of the image for density unevenness measurement and each of the nozzles, before the image for density unevenness measurement is dried; a density measurement value conversion step of converting the acquired density measurement value into a conversion density measurement value corresponding to a post-dry density measurement value, using a defect correction unit density measurement value conversion value for a nozzle that corresponds to the correction nozzle and a non-defect correction unit density measurement value conversion value for a nozzle that does not correspond to the correction nozzle, where the defect correction unit density measurement value conversion value and the non-defect correction unit density measurement value conversion value show a conversion relationship of the density measurement value of each set gradation value before and after drying for each of the nozzles; an unevenness correction value derivation step of deriving a new unevenness correction value using the conversion density measurement value, and an unevenness correction processing step of performing unevenness correction processing on another image data based on the new unevenness correction value.