Welcome to Xiaoyi's homepage.

Email: xiaoyi@eecs.berkeley.edu

About Me

I'm a second year grad student in EECS department at UC Berkeley. I'm working toward my Master's degree under the supervision of Prof. Avideh Zakhor. This work is supported by NSF Grant ANI 9997442.

Research Project

My current research project is multiple description coding (MDC). MDC is an error resilient source coding scheme that creates multiple bitstreams of approximately equal importance. The reconstructed signal based on any single bitstream has an acceptable quality. However, a higher quality reconstruction can be achieved with larger number of bitstreams. We develop a multiple (2) description video coding scheme based on the 3 loop structure originally proposed in [1]. We modify the discrete cosine transform structure to the matching pursuit framework and evaluate performance gain using maximum likelihood (ML) enhancement when both descriptions are available. We find that ML enhancement works best for low motion sequences and results in gains of up to 1.3 dB in terms of average PSNR. Rate distortion performance is characterized. Performance comparison is made between our MDC scheme and single description coding (SDC) schemes over lossy channels, including two state Markov channels and Rayleigh fading channels. We find that MDC outperforms SDC in bursty slowly varying environments. In the case of Rayleigh fading channels, interleaving helps SDC close the gap and even outperform MDC depending on the amount of interleaving performed, at the expense of additional delay. [See results.]


[1] A. Reibman, Y. Wang, M. Orchard, and R. Puri, "Multiple description coding for video using motion compensated prediction," in Proc. ICIP 99, pp. 837-841, October 1999.
  last updated: 2/10/2001