Hadamard transform seperation of NTSC component signals

The transmission of NTSC composite color images over digital communication channels is generally accomplished by coding the less correlated component signal, YIQ. Unless the video source is available, the component signals are separated from the composite signal by using comb-filters. Comb-filtering is generally performed in the temporal domain. This paper shows that by properly sampling the NTSC composite color signal at four times the color subcarrier, the Walsh-Hadamard transform acts like a comb filter and separates the YIQ components of the composite signal. The YIQ components will be mapped into specific locations of the coefficient matrix.