Color coding method for expanding palette by including colors derived by averaging numeric codes of actual palette colors

摘要

A color interpolation circuit allows information uniquely identifying one of six colors to be stored by using only two binary bits of memory storage, and allows information uniquely identifying one of 120 colors to be stored by using only four binary bits of memory storage. This is accomplished by storing only the foreground, edge, and background colors (i.e., herein referred to as "independent" colors), and an "interpolate operator" code, and by providing circuitry to properly interpret and process the interpolate operator code to generate "intermediate colors". This permits a 33% reduction of memory size and reduces the "fetch speed" requirements of associated on-screen display (OSD) scan converter circuitry.