The design, implementation and analysis of a wavelet-based video codec

The Wavelet Transform has been shown to be highly effective in image coding applications. This thesis describes the development of a new wavelet-based video compression algorithm which is based on the 3D wavelet transform, and requires no complicated motion estimation techniques. The proposed codec processes a sequence of images in a group of frames (GOF) by first transforming the group spatially and temporally, in order to obtain a GOF of 3D approximation and detail coefficients. The codec uses selective prediction of temporal approximation coefficients in order to decorrelate transformed GOFs. Following this, a modified version of Said and Pearlman's image coding technique of Set Partitioning in Hierarchical Trees is used as a method for encoding the transformed GOF. The compression algorithm has been implemented in software, and tested on seven test sequences at different bit-rates. Experimental results indicate a significantly improved performance over MPEG 1 and 2 in terms of picture quality, for sequences filmed with a stationary camera. The codec also performs well on scenes filmed with a moving camera, provided that there is not a large degree of spatial detail present. In addition, the proposed codec has several attractive features. It performs well without entropy coding, and does not require any computationally-expensive motion estimation methods, such as those used by MPEG. Finally, a substantial advantage is that the encoder generates a bit-stream which allows for the progressive transmission of video, making it well-suited to use in video applications over digital networks.

Grantor dc:publisher.institution

Department of Electrical Engineering

Year dc:date.issued

1998

Author dc:creator

• Servais, Marc Paul

Advisor dc:contributor.advisor

• De Jager, Gerhard

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/9697

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/9697