tailieunhanh - Báo cáo hóa học: " Facial Image Compression Based on Structured Codebooks in Overcomplete Domain"

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: Facial Image Compression Based on Structured Codebooks in Overcomplete Domain | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 69042 Pages 1-11 DOI ASP 2006 69042 Facial Image Compression Based on Structured Codebooks in Overcomplete Domain J. E. Vila-Forcen S. Voloshynovskiy O. Koval and T. Pun Stochastic Image Processing Group CUI University of Geneva 24 ruedu General-Dufour Geneva 1211 Switzerland Received 31 July 2004 Revised 16 June 2005 Accepted 27 June 2005 We advocate facial image compression technique in the scope of distributed source coding framework. The novelty of the proposed approach is twofold image compression is considered from the position of source coding with side information and contrarily to the existing scenarios where the side information is given explicitly the side information is created based on a deterministic approximation of the local image features. We consider an image in the overcomplete transform domain as a realization of a random source with a structured codebook of symbols where each symbol represents a particular edge shape. Due to the partial availability of the side information at both encoder and decoder we treat our problem as a modification of the Berger-Flynn-Gray problem and investigate a possible gain over the solutions when side information is either unavailable or available at the decoder. Finally the paper presents a practical image compression algorithm for facial images based on our concept that demonstrates the superior performance in the very-low-bit-rate regime. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION The urgent demand of efficient image representation is recognized by the industry and research community. Its necessity is highly increased due to the novel requirements of many authentication documents such as passports ID cards and visas as well as recent extended functionalities of wireless communication devices. The document ticket or even entry pass personalization are often requested