The luminance and chrominance components in NTSC color television composite video signal are not separated completely. Consequently, component separation from NTSC composite signal is an important step for good image reproduction in television receiver and in color image coding.
This paper represents an adaptive filtering algorithm to separate luminance and chrominance signals from NTSC signal, by adaptively using two different filters according to the local image characteristics so as to reduce separation error.
The adaptation circuit compares the chrominance band components in horizontal and vertical direction, and the direction which has smaller chrominance band components is chosen as better filtering direction. The next higher order maximally flat filter is used as basic horizontal filter which fit better to signal spectrums than lowest order maximally flat filter, and the lowest order maximally flat filter is used as basic vertical filter.
Using 4fsc sampled NTSC composite signal, the filter is designed as easily implementable digital FIR filter form. Computer simulation using various artificial patterns and real images shows better performance in comparison to conventional fixed coefficient filters.
