Color palette having repeat color data

摘要

The present invention involves an improvement in color palettes which translate pixel color codes into color data words which have differing bits. In the color palette a stream of pixel color codes from a pixel map memory enables sequential selection of one of a set of color registers. The color data word stored in the selected color register controls the color of the current pixel within the video display. The innovation of the present invention is providing at least one color data word within the color palette which has no corresponding color of its own but which enables a repetition of the previous color. The entire visual image can be redefined by merely changing the pixel color codes at the first scanned edges of color regions if the entire pixel map memory is filled with pixel color codes which refer to repeat color data words. Hidden objects formed in the pixel map memory can be made to appear or disappear by redefining the color data words in the color registers. In the preferred embodiment of the present invention the recalled color data word are stored in color data buffer which controls the video output signals. Repeat color data words disable the storage operation of the color data buffer thus leaving the contents of the color data buffer are unchanged, thereby repeating the previous color.