Abstract: Video systems generally include chroma processors. The chroma processor may be configured as a chroma keyer, a key signal generator or a color collector. The chroma processor includes dual input look-up tables which are loaded by a central processor. The dual input look-up tables may be read and written to simultaneously. The look-up tables are addressed by chrominance signals, luminance signals or key signals input into the chroma processor. The look-up tables provide an exceptionally fast apparatus and exceptionally flexible method of keying one or more simultaneous regions of the display based on one or more unique chroma/luma combinations, new key signals, chrominance signals, and luminance signals. The chroma processor receives color modification parameters from a software user interface. Preferably, the chroma processor utilizes Y luminance signals, and U and V chrominance signals.

Abstract: A phase responsive video parameter control system operative for correcting hue, saturation, and luminance of a phase encoded component of a composite video signal. A digital phase detector detects the instantaneous hue of the video image, and provides a signal which selects which one of a plurality of color intervals or bands the detected instantaneous hue falls in. Prestored digital correction values associated with the selected color interval are retrieved from memory and converted into analog correction signals which modify the phase, amplitude, and DC level of the composite video signal. New digital correction values, which reflect operator control panel adjustments, may be loaded into memory during the vertical retrace interval, thereby allowing frame-by-frame color correction.