Patent ID: 7385731
Filing Date: 2008-06-10
Classification: H04N

Abstract:
1. An image processing system for processing a digital multi-color image for reproduction thereof on a color image reproduction system including an image-carrying member by sequentially and complementary forming a plurality of registered separation images of colored marking particles on said image-carrying member, said image processing system comprising: a generation module configured to generate from said digital multi-color image a sequence of image signals for a selection of process colors, each image signal of said sequence of image signals being associated with a digital separation image of a process color of said selection of process colors and specifying an image density value for each pixel of said digital separation image of said process color; and a conversion module configured to convert said sequence of image signals into a sequence of corresponding printing signals, each printing signal of said sequence of corresponding printing signals indicating for each pixel of a corresponding digital separation image whether an image dot of marking particles of a corresponding process color is to be formed; wherein said conversion module is configured to convert at least one image signal selected from a second image signal of said sequence by using a matrix-dither technique into a corresponding printing signal, said matrix-dither technique being such that the corresponding printing signal is built up from a raster of a two-dimensional matrix structure including threshold values being arranged in a predetermined order by comparing an input density value of each pixel of a corresponding digital separation image with a corresponding threshold value, said predetermined order being such that, by gradually increasing the input density value, a linear growth pattern is generated in a predetermined direction by alternately adding image dots to both sides of printed images dots previously printed in the predetermined direction.