Patent ID: 7468814

Claim:
A method for analyzing an image, said image formed by an array of pixels and generating half tone output, said method comprising: performing an error diffusion analysis by applying an error diffusion threshold to said array of pixels within said image to determine a tonal value for each pixel and distributing any differences between said tonal value and said threshold to adjacent pixels within said array of pixels; determining a divisor constant for each pixel based on said tonal value for each pixel; tiling a clustering screen over said plurality of pixels, said clustering screen including an array of clustering thresholds; and modulating the application of said clustering screen by reducing the threshold values within said clustering screen by said divisor constant to generate half tone output, wherein the effects of said clustering screen are increased for deeper tonal values and the effects of said clustering screen are decreased for lighter tonal values; and wherein said method is performed by a controller in a printing device or on a computer processor.