tailieunhanh - Báo cáo hóa học: "A Packetized SPIHT Algorithm with Overcomplete Wavelet Coefficients for Increased Robustness"

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: A Packetized SPIHT Algorithm with Overcomplete Wavelet Coefficients for Increased Robustness | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 19156 Pages 1-8 DOI ASP 2006 19156 A Packetized SPIHT Algorithm with Overcomplete Wavelet Coefficients for Increased Robustness Y. Sriraja and Tanja Karp Department of Electrical and Computer Engineering Texas Tech University Lubbock TX 79409-3102 USA Received 19 August 2004 Revised 3 March 2005 Accepted 25 March 2005 This paper presents a wavelet-based image encoding scheme with error resilience and error concealment suitable for transmission over networks prone to packet losses. The scheme involves partitioning the data into independent descriptions of roughly equal lengths achieved by a combination of packetization and modifications to the wavelet tree structure without additional redundancy. With a weighted-averaging-based interpolation method our proposed encoding scheme attains an improvement of about dB in PSNR over other similar methods. We also investigate the use of overcomplete wavelet transform coefficients as side information for our encoding scheme to improve the error resilience when severe packet losses occur. Experiments show that we are able to achieve a high coding performance along with a good perceptual quality for the reconstructed image. Copyright 2006 Y. Sriraja and T. Karp. 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 Efficient delivery of images over data communication networks requires the maintenance of a balance between available bandwidth and perceptual quality of the received data with minimum transmission delays. With recent increase in use of wireless communications and multimedia applications error-resilient capabilities need to be incorporated into image coders with good compression performances. Packet-switched networks are very .