Motion-compensated layered video coding for playback scalability

We propose a multilayered video coding scheme based on motion estimation which enables a decoder to dynamically change its temporal and spatial resolution during playback. In the proposed scheme, a new motion-prediction structure with a temporal hierarchy of frames is adopted to afford temporal resolution scalability and the wavelet decomposition with a new intra-update algorithm is used to offer spatial scalability. Experimental results show that the proposed scheme exhibits a higher compression ratio than conditional replenishment schemes because it further reduces the temporal redundancy using motion estimation. Also the proposed intra-update technique enables adaptation to dynamic change of spatial resolution with the effective follow-up of prediction in the decoder while preventing the large peaks in bit rate. Therefore, the proposed scheme is expected to be effectively used in heterogeneous environments such as the Internet, ATM, and wireless networks where dynamic scalability and interoperability are required.