Motion vector composition algorithm for spatial scalability in compressed video
Mei‐Juan Chen, Ming-Chung Chu, Shen-Yi Lo · IEEE Transactions on Consumer Electronics · 2001
Spatial scalable encoding of visual data has several applications, including browsing visual databases, querying multimedia databases, interactive multimedia communications, etc. To convert a compressed video sequence to a lower spatial resolution compressed video, it may decode the original bit-stream, down-sample each frame, and encode. The computation-intensive motion estimation will be included in the transcoder. The re-use of motion vectors extracted from incoming video bit-streams during transcoding has been widely accepted. This paper proposes a new algorithm to estimate the motion vector of the reduced low-resolution video by only using the original motion vectors and DC coefficients in the compressed bit-stream. By taking into account the spatial activity measurement to generate better prediction for the composed motion vector, higher quality and lower complexity than previous works are achieved by the proposed method.