Patent ID: 8441680
Filing Date: 2013-05-14
Classification: H04N

Abstract:
1. A method for calibrating an image printing system comprising a plurality of parallel printers, each of the printers having a minimum luminance value, the method comprising: determining a minimum luminance value profile for the plurality of printers in the image printing system based on the minimum luminance values of each of the printers in the image printing system; determining a black point compensation function based on the determined minimum luminance value profile; adjusting luminance values for input image data using the determined black point compensation function; and rendering, with the parallel printers, images on substrates based on the input image data with adjusted luminance levels, wherein the black point compensation function is configured to retain shadow details in the images rendered by the plurality of parallel printers and to ensure the shadow details in the rendered images across the plurality of parallel printers match with each other, wherein the black point compensation function is determined using the following equation: where x a is a constant.