Filter to Remove Spurious Colors From Computer-Generated Composite Video Images
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Computer-generated composite video displays of text and graphics have performance problems which result from contradictions between the requirements for such images and those of NTSC composite video encoding. The filter described here alleviates one of these consequences, namely spurious coloring of monochrome (black and white) text and graphic items. The problem of spurious coloring is caused by the fact that pixels small enough to be useful for computer displays have frequency components in and above the frequency range reserved in NTSC for chroma information. These components are incorrectly interpreted by the display as color instead of luminance information.