Patent ID: 8493623
Filing Date: 2013-07-23
Classification: G03G,G06K,H04N

Abstract:
1. A method of printing using a printer that includes at least one color module to be used in a printing operation, each color module including an exposure device having a plurality of pixel locations extending transverse to a process direction of the printer, the method comprising: printing a single target for the at least one color module of the printer, with the single target including a plurality of uniform density images that are printed in part at different pixel locations of the plurality of pixel locations, each uniform density image having a respective, different requested density values; scanning the single printed target to produce scanned raster data representing reflection densities for the plurality of uniform density images; producing, for each uniform density image, a respective streak signal, each derived from a difference from a fitted spline curve and processed raster data at different pixel locations of the plurality of pixel locations; determining for individual pixel locations of the plurality of pixel locations, a correlation among the streak signals for respective, different uniform density images; generating a correction profile for individual pixel locations of the plurality of pixel locations based on the determined correlation; projecting at least one of the streak signals onto the correction profile; correlating the requested density values and the results of the projecting step to produce respective correction profile magnitudes for individual pixel locations in the plurality of pixel locations; and printing with at least one color module of the printer using the respective correction profile magnitudes for the individual pixel locations in the plurality of pixel locations to compensate for the non-uniformities detected in the target.