Abstract: Undesired color discontinuities in the display of color television signals which were processed digitally and which have separately coded luminance and chrominance signals are eliminated by controlling the luminance signals with a broadband control signal and the chrominance signals with a narrowband control signal. For this purpose, the available broadband control signal is filtered to create the narrowband signal and a multiplexer is provided to apply either the filter output or the broadband signal to a multiplier whose second set of inputs receives luminance and chrominance signals in a predetermined order in each cycle.

Abstract: To provide a readily available digital video frequency control signal derived from a video signal, one of the two chroma components is multiplied with the slope (m) of the angle of the chroma signal, and the respective product is subtracted from the other chroma component. The absolute value of the subtraction is subtracted from the absolute value of the first chroma component signal which had been multiplied with a factor representing the opening angle of the chroma sector. Upon simultaneous presence of a positive result in the subtraction, and a result in excess of a minimum threshold, representing minimum chroma saturation, a digital control signal is derived which can be used in further signal processing.