<title>Mesh-based scalable image coding with rate-distortion optimization</title>

Abstract

Recent development in video coding research deals with the use of hierarchical and/or adaptative mesh for video representation. Concurrently, transmitted bit rates have to be reduced to adapt to the network available bandwidth. Some previous works deal with adaptative node sampling according to image content. However, adaptative hierarchical proposed approaches do not optimize a compromise between distortion and bitrate: the representation coding cost is often stated but not taken into account as a constraint. Compared to these methods, this paper proposes for considering an adaptative hierarchical mesh based representation whose splitting criterion optimizes both the coding cost and the image rendering. Jointly, node value optimization, adaptative quantization, cheap coding tree and a wavelet approach are presented. To illustrate our different proposed methods, experimental results are shown and compared to the JPEG picture coding format.

Mesh-based scalable video coding with rate-distortion optimization

“…12(x,y)=Ii(x+dx,y+dy) (4) We introduce a mesh-based motion estimation scheme for image sequence : given the motion of the node points, we are able to reconstruct the image. The major problem consists in estimating as well as possible the motion vectors between frames in order to encode and reconstruct an image given the previous one.…”

Continuous metrics and mesh adaptation

“…Mesh adaptive interpolation is an answer to this problem, already used in image processing [16]. Fig.…”