Color stochastic screening with optimal color dot placement for display devices having arbitrary aspect ratios

An apparatus for generating a spatial-priority matrix for specifying an order for forming display elements in a stochastic screen for use in displaying a color image in a device, said apparatus comprising:

• means for receiving a spatial-priority signal representing values of a plurality of elements in a square matrix, said values representing an order of fill in a square stochastic screen,
• means for receiving an aspect-ratio signal representing one or more ratios of dimensions of output presented by said device,
• means for forming groups of elements in said spatial-priority matrix, each group corresponding to a respective element in said square matrix and containing a plurality of elements according to said aspect-ratio signal and arranged to have dimensions inversely proportional to said dimensions of output, and
• means for assigning values to elements in said groups of elements in response to said spatial-priority signal, wherein an element in a respective group of elements is assigned a value according to the value of the element in said square matrix corresponding to said respective group of elements.

A medium readable by a machine embodying a program of instructions for execution by said machine to perform a method for generating a spatial-priority matrix for specifying an order for forming display elements in a stochastic screen for use in displaying a color image in a device, said method comprising:

• receiving a spatial-priority signal representing values of a plurality of elements in a square matrix, said values representing an order of fill in a square stochastic screen,
• receiving an aspect-ratio signal representing one or more ratios of dimensions of output presented by said device,
• forming groups of elements in said spatial-priority matrix, each group corresponding to a respective element in said square matrix and containing a plurality of elements according to said aspect-ratio signal and arranged to have dimensions inversely proportional to said dimensions of output, and
• assigning values to elements in said groups of elements in response to said spatial-priority signal, wherein an element in a respective group of elements is assigned a value according to the value of the element in said square matrix corresponding to said respective group of elements.