Abstract: Improvements in a phase responsive video parameter control system for correcting hue, saturation and luminance of a phase encoded composite video signal are disclosed. The system has a phase detector that detects which of a plurality of color intervals or hue bands the instantaneous signal falls in. Luminance, hue and saturation corrections for each band are applied to the uncorrected video. The improvements include correction signal selection circuit that select the correction signals twice per subcarrier cycle, a damping circuit that smooths the transition between two correction signals when the hue moves to a different color interval or band, and a phase shifter that allows the centers of the bands to be moved without changing the width of the band.

Abstract: A video parameter control system operative for selecting a spatial region in a video image for correction, particularly useful for a scene by scene color corrector. A track ball allows selection of a spatial region by drawing a "window" with a cursor around an object of interest in the picture. The operator then adjusts controls for the selected region or window. A first set of correction signals will be stored for the selected region; a separate second set of correction signals is stored for areas of the picture outside the selected regions, thereby allowing multiple sets of corrections for a given frame. A plurality of windows can be selected for each video frame. If an object within the window translates across the screen over a plurality of frames, or is dissolved, zoomed, or warped, the window tracks the movement of the object.

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.