Color halftoning for printing with multiple inks

Abstract

The method reproduces on an output device an electronic image having color pixels, each color pixel being represented by K spatially corresponding component pixels, K>1, each component pixel having an input pixel value, the output device being capable of rendering Nj intensity levels for a component pixel j, 1≦j≦K, thereby defining N1*N2* . . . *NK intensity level combinations, the method comprising the steps of: computing for any color pixel a scalar value which is a function of at least one of said input pixel values of said spatially corresponding component pixels; quantizing said scalar value by a multilevel halftoning process to obtain for said color pixel a quantized scalar value; using said quantized scalar value to select, out of all said intensity level combinations, a subset of intensity level combinations; selecting one combination out of said subset; using said selected combination for reproducing said color pixel by said output device. In a specific embodiment the multilevel halftoning process is a multilevel error diffusion process.

Dependencies are inferred from the claim text.