Abstract
Based on our previous work on distributed video coding with low complexity motion estimation at the encoder, we propose in this paper a more flexible system, providing the possibility that the encoder and the decoder cooperate in motion estimation and share the computational bulk of it. In this system, not only the encoder but also the decoder is capable of improving the coding efficiency by spending more computational power in motion estimation. Experimental results show that the cooperation of the encoder and the decoder can reduce the total computational complexity and at the same time improve the coding efficiency. In addition, we propose a simple scheme to order the intensity of motion activity for different macroblocks. When the encoder has limited computational power, we apply motion estimation only to the macroblocks with relatively large motion. This leads to an efficient use of computational power at the encoder.