Patent ID: 7719722

Claim:
A method of halftoning an image having at least one of pixels forming image highlights and pixels forming image shadows performed by an image processing unit (IPU) halftone generator for multi-pass rendering wherein different pixel locations are rendered in each pass comprising: generating a stochastic screen pixel turn-on sequence of turn-on sequence values representing the turn-on sequence order for corresponding image pixels from an input image; partitioning the stochastic screen pixel turn-on sequence into a plurality of partitions, wherein each partition corresponds to a different pass of a multi-pass printer used in printing the image; re-ordering the stochastic screen pixel turn-on sequence to restrict a substantial majority of the pixels turned on to render a tone to the minimum number of passes required to produce the tone in the image, the re-ordering restricting at least one of pixels in the image highlights turned on for printing to a minimum number of partitions needed for rendering the image highlights and pixels in the image shadows not turned on for printing to a minimum number of partitions needed for rendering the image shadows; and generating a stochastic halftone screen using the re-ordered stochastic screen pixel turn-on sequence.