Video Compression using Wyner-Ziv Codes
Predictive coding is posed as a variant of the Wyner-Ziv coding, and problems in source and channel coding of video are addressed in this framework.
Video Encoding using Coset Codes
This project deals with scalable coding and robust Internet streaming of predictively encoded media. We frame the problem of predictive coding as a variant of the Wyner-Ziv problem in Information theory. Subsequently, LDPC based coset code constructions are used to compress the media in a scalable, error-resilient manner. In particular, we propose a video encoding algorithm that prevents the indefinite propagation of errors in predictively encoded video—a problem that has received considerable attention over the last decade. This is accomplished by periodically transmitting a small amount of additional information, termed coset information, to the decoder, as opposed to the popular approach of periodic insertion of intra-coded frames. Perhaps surprisingly, the coset information is capable of correcting for errors, without the encoder having a precise knowledge of the lost packets that resulted in the errors. In the context of real-time transmission, the proposed approach entails a minimal loss in performance over conventional encoding in the absence of channel losses, while simultaneously allowing error recovery in the event of channel losses.
- A. Sehgal, A. Jagmohan, N. Ahuja, Wyner-Ziv Coding of Video: Applications to Error Resilience, IEEE Trans. Multimedia, April 2004, pages 249 – 258.
- A. Sehgal, A. Jagmohan, N. Ahuja, A State-free Causal Video Encoding Paradigm, Proc. IEEE Int. Conf. Image Processing, 2003, pp. I-605-608.
- A. Sehgal, A. Jagmohan, N. Ahuja, Scalable Predictive Coding and the Wyner-Ziv Problem, Proc. IEEE Int. Conf. Comm. Systems, 2002.
- A. Sehgal, N. Ahuja, Robust predictive coding and the Wyner-Ziv problem, Data Compression Conference, Snowbird, Utah, 2002. pp. 103.