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 luminance selection apparatus for correcting the hue, saturation and luminance of an input color video signal as a function of the luminance of the signal. The system allows setting and storing luminance threshold levels which are used in conjunction with other color selection circuitry to select a region of interest in a video image being displayed. An operator selects a particular hue of interest with color selection circuitry, and then sets a luminance threshold level which discriminates between the same or similar hues in a video image which differ in luminance. In one embodiment, pre-stored digital correction values are retrieved from memory and converted into analog correction signals which modify the phase, amplitude and DC level of the composite video signal only when the input luminance exceeds the threshold level.

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 touch-sensitive potentiometer for an operator control panel. A linear strip having a polymeric resistor film is provided as an operator actuatable control. The stray capacitance of an operator's body, when the operator touches the strip along its length, unbalances a transformer bridge and provides a voltage proportional to the position of the operator's finger along the length of the polymeric resistor. The potentiometer is suitable for use in any operator control environment where it is desired to (1) rapidly and quickly approach a control range without multiple turns required by optical position encoder-type control devices, or (2) rapidly and quickly be reset to a null or zero state upon the completion of a control in preparation for a subsequent control.

Abstract: A luminance selection apparatus for correcting the hue, saturation and luminance of an input color video signal as a function of the luminance of the signal. The system allows setting and storing luminance threshold levels which are used in conjunction with other color selection circuitry to select a region of interest in a video image being displayed. An operator selects a particular hue of interest with color selection circuitry, and then sets a luminance threshold level which discriminates between the same or similar hues in a video image which differ in luminance. In one embodiment, pre-stored digital correction values are retrieved from memory and converted into analog correction signals which modify the phase, amplitude and DC level of the composite video signal only when the input luminance exceeds the threshold level.

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 parameter control system operative for correcting hue, saturation and luminance of a color video signal. Circuitry for generating and positioning a cursor on a video monitor displaying an uncorrected input video signal allows selection of a colored region on the monitor. Circuitry responsive to the cursor location selects one of a plurality of color correction circuits to become operative for directing video parameter correction such as hue, saturation and luminance only to regions in the video image corresponding to the hue selected by the cursor. In one embodiment, prestored digital correction values are retrieved from memory and converted into analog correction signals which modify the phase, amplitude and DC level of the composite video signal. In another embodiment, independent color derivative signals are employed in conjunction with the location of the cursor to route signals from operator controls to a channel carrying video signals of the selected hue.