Title :
Context based optimal shape coding
Author :
Melnikov, Gerry ; Katsaggelos, Aggelos K. ; Schuster, Guido M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Northwestern Univ., Evanston, IL, USA
Abstract :
This paper investigates how context-based DPCM techniques can be used in conjunction with an operationally rate-distortion (ORD) optimized shape coder. Object contours are approximated by connected second-order spline segments, each defined by three consecutive control points, and, in the case of the inter mode, by segments of the motion-compensated reference contours. In scalable intra mode and non-scalable inter mode shape coding, consecutive control points are encoded predictively, using an angle and run framework, with respect to corresponding contexts in the reference frame and the base layer, respectively. We employ a novel criterion for selecting global object motion vectors in the inter mode, which further improves efficiency
Keywords :
data compression; differential pulse code modulation; edge detection; image segmentation; motion compensation; optimisation; rate distortion theory; splines (mathematics); video coding; MPEG-4 standard; base layer; context based optimal shape coding; context-based DPCM techniques; global object motion vectors; motion-compensated reference contours; nonscalable inter-mode shape coding; object contours; operationally rate-distortion; optimized shape coder; predictive encoding; reference frame; scalable intra-mode; second-order spline segments; Joining processes; MPEG 4 Standard; Motion control; Petroleum; Rate-distortion; Redundancy; Scalability; Shape control; Spline; Video coding;
Conference_Titel :
Multimedia Signal Processing, 1999 IEEE 3rd Workshop on
Conference_Location :
Copenhagen
Print_ISBN :
0-7803-5610-1
DOI :
10.1109/MMSP.1999.793853
