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.

Abstract: A video signal control system including circuitry for providing a plurality of independent color video signals, control circuitry for separately varying the magnitude of each of the independent color video signals, circuitry for combining the controlled independent color video signals to provide change-in-red, change-in-blue, and change-in-green, and change-in-luminance correction signals, and second combining circuitry for adding together the correction signals with conventional video signals to provide corrected video signals. The system thereby provides independent control over portions of a video scene which are predominantly the color of the independent color channel, without affecting spectral content, neutral tones, and color mixtures. The present invention also includes an improved apparatus for controlling parameters requiring repetitive adjustments, including operator signal means responsive to provide control signals indicative of a desired increase or decrease in the controlled parameter.