Abstract: A hue control circuit for adjusting the color phase of a composite PAL television signal without demodulating the chrominance component of the composite PAL television signal uses a polyphase interpolator to change the phase of the modulated chrominance component. A set of coefficients corresponding to a desired hue adjustment is applied to the polyphase interpolator. A hue coefficient address circuit addresses a coefficient memory containing a plurality of sets of coefficients, the sets being in complementary pairs. During each horizontal blanking line interval for a given desired hue adjustment the hue coefficient address circuit swaps the sets of coefficients between the complementary pair defining the desired hue adjustment in synchronization with the alternating sign of one of the color difference components of the modulated chrominance component on a line by line basis.

Abstract: The color balance, hue, saturation, luminance, and other parameters of digital video signals are corrected entirely in the digital domain. Correction signals are combined with the digital video signals and new digital video signals are created to replace the original signals. Thus, color correction is performed without victorial addition or similar techniques. A digital "six-vector" color correction circuit, as well as an infinitely variable color selection correction circuit are provided. Also provided is a window for isolating the color corrections, with the capability of limiting the isolation provided by the window to a single selected hue so that one color can be corrected under the restrictions of the window, while others are corrected free of those restrictions. A separate window can be provided simultaneously for each of six colors and the infinitely variable correction circuit. Different corrections of the same color can be made inside and outside of the window.