A motion-compensated interframe coding system for an NTSC color television signal has been developed. The output of a local decoder is used in the form of a

separated signal. Motion vectors are detected using the

signal, and the

signal and both baseband components of the

signal are motion-compensated. The motion-compensated signals are reencoded into an NTSC signal to provide a motion-compensation interframe prediction in the NTSC format. Real-time experimental hardware has been built. The sampling frequency and bit rate of this system are 10.7 MHz and 1.6 bits/ sample, respectively. This value includes all overhead information such as motion vectors and other control information. An assessment has been made of the picture quality of coded/decoded pictures taken from a variety of broadcast television programs. The quality was good for almost all the programs. A subjective test of picture quality was performed under stringent conditigns. The lowest value for the picture quality of the most difficult scenes at 1.6 bits/sample was 3.3 on a five-grade impairment scale.