This paper presents an adaptive algorithm for motion compensated color image coding. The algorithm can be used for video teleconferencing or broadcast signals. Activity segmentation is used to reduce the bit rate and a variable stage search is conducted to save computations. The adaptive algorithm is compared with the nonadaptive algorithm and it is shown that with approximately 60 percent savings in computing the motion vector and 33 percent additional compression, the performance of the adaptive algorithm is similar to the nonadaptive algorithm. The adaptive algorithm results also show improvement of up to 1 bit/pel over interframe DPCM coding with nonuniform quantization. The test pictures used for this study were recorded directly from broadcast video in color.

In motion compensated coding of the NTSC composite video signal using block matching method, the motion vector can be determined either by using the composite signal itself or by using only the luminance component of the composite signal. However the computational requirement and the compression obtained may be quite different in the two cases. This paper provides this comparison using an adaptive variable stage motion search motion compensated coding scheme. It is found that for approximately the same signal to noise power ratio, composite coding requires more computations but also results in higher data compression as compared to coding the composite signal based on luminance component only.

A summary of the results of a joint United States and Canadian program on subjective measurements of the picture degradation caused by noise and interference on an NTSC encoded color television signal is given in this paper. The effects of system noise, cochannel and adjacent channel interference, and both single entry and aggregate as well as a combination of these types of interference were subjectively evaluated by expert and nonexpert viewers under reference conditions. These results were used to develop the rationale used at RARC '83 to establish the service quality objective for planning the DBS service for the American continents.