APPARATUS AND METHOD FOR ENCODING AND DECODING A NTSC COLOR VIDEO SIGNAL

The present disclosure describes a color video signal encoding system for generating a NTSC color image composite signal for a television receiver. A luminance signal Y and two chrominance signals I and Q are modulated on a color subcarrier having a frequency F.sub.sc. The television receiver has an intrafield vertical sampling frequency F.sub.1. The encoding system comprises a first non separate two dimensional filter for low pass filtering the chrominance signal I, and a second non separable two dimensional filter for low pass filtering the chrominance signal Q. A third non separable two dimensional filter is used for band-stop filtering the luminance signal. The third filter has a stop band centered on .+-.F.sub.sc and .+-.F.sub.1 /2. The stop band has a shape similar to the shape of the band pass of the first filter so that said chrominance signals I and Q filtered by said first and second filter means can be inserted in the band covered by said stop band. The encoding system also comprises a modulator connected to the output of the first and second filter and an adder for adding signals generated by the third filter and the modulator, and generating a signal representative of the NTSC color image composite signal. The present disclosure also describes a color video signal decoding system and two methods for respectively encoding and decoding the NTSC color image composite signal.