Chrominance inverting all-pass filter.

摘要

An all-pass filter provides inversion of a chrominance component in a composite signal without separating the chrominance component from the composite signal, to provide for example, synthesizing composite video from a previous line of video. The filter includes an input (26') for receiving the composite signal along a subsequent signal path, and the application of selected, preferably symmetrical weighting factors to selected locations along the signal path. The path includes selected delay means (58-64) coupled to define a filter output via summing means (66). The latter provides the composite signal with inverted chrominance without an objectionable change in the relative phase and amplitude of the luminance components relative to the inverted chrominance.