Patent ID: 6830306
Filing Date: 2004-12-14
Classification: B41J

Abstract:
A method for modifying a digital image having an array of raster lines, each raster line having an array of image pixels, to produce a modified digital image suitable for printing on an inkjet printer containing at least one printhead having nozzles each of which when activated is adapted to produce one or more ink drops in a raster line, such that unwanted optical density variations in the print are reduced, comprising:a) determining an optical density parameter for each nozzle in the printhead; b) determining a line correction factor for a given raster line in response to the optical density parameter for each nozzle in the printhead and the raster line number; and c) modifying the number of ink drops produced each pixel in the given raster line by reducing or increasing the number of ink drops provided by the nozzle in response to the line correction factor to produce the modified digital image.