tailieunhanh - Báo cáo hóa học: "Research Article Unequal Error Protection Techniques Based on Wyner-Ziv Coding"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Unequal Error Protection Techniques Based on Wyner-Ziv Coding | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2009 Article ID 474689 13 pages doi 2009 474689 Research Article Unequal Error Protection Techniques Based on Wyner-Ziv Coding Liang Liang 1 Paul Salama 2 and Edward J. Delp EURASIP Member 1 1 Video and Image Processing Laboratory VIPER School of Electrical and Computer Engineering Purdue University West Lafayette IN 47907 UsA 2 Department of Electrical and Computer Engineering Indiana University Purdue University at Indianapolis Indianapolis IN 46202 USA Correspondence should be addressed to Edward J. Delp ace@ Received 31 May 2008 Revised 2 November 2008 Accepted 17 March 2009 Recommended by Frederic Dufaux Compressed video is very sensitive to channel errors. A few bit losses can stop the entire decoding process. Therefore protecting compressed video is always necessary for reliable visual communications. Utilizing unequal error protection schemes that assign different protection levels to the different elements in a compressed video stream is an efficient and effective way to combat channel errors. Three such schemes based on Wyner-Ziv coding are described herein. These schemes independently provide different protection levels to motion information and the transform coefficients produced by an AVC encoder. One method adapts the protection levels to the content of each frame while another utilizes feedback regarding the latest channel packet loss rate to adjust the protection levels. All three methods demonstrate superior error resilience to using equal error protection in the face of packet losses. Copyright 2009 Liang Liang et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction Channel errors can result in serious loss of decoded video quality. Many error resilience and .