tailieunhanh - Báo cáo hóa học: " Filters Ranking for DWT-Domain Robust Digital Watermarking"

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: Filters Ranking for DWT-Domain Robust Digital Watermarking | EURASIP Journal on Applied Signal Processing 2004 14 2093-2101 2004 Hindawi Publishing Corporation Filters Ranking for DWT-Domain Robust Digital Watermarking Martin Dietze Department of Information Systems University of Buckingham Buckingham MK18 1EG UK Email Sabah Jassim Department of Information Systems University of Buckingham Buckingham MK18 1EG UK Email Received 30 March 2003 Revised 24 September 2003 In recent years a number of wavelet-based watermarking schemes have been proposed and exhibited improved qualities. The choice of a wavelet filter bank for a digital watermarking scheme can have a significant influence on the scheme s performance in terms of image quality and robustness. We present the results of experiments conducted using two different embedding algorithms one blind and one nonblind using a number of popular filter banks. The aim is to find filters that exhibit optimal performance with respect to specified requirements. The results demonstrate that the subband depth of embedding has the most significant influence on the filter bank choice. The kind of attack and the kind of embedding are also important while marking intensity and compression ratio seem to affect the performance to a less extent. Additionally we show that out of the two embedding methods the quantization-based blind one leads to better overall results than the popular nonblind one. Keywords and phrases watermarking embedding SCS spread spectrum wavelet filters. 1. INTRODUCTION Robust digital watermarking . for copyright protection has gained increasing importance with the availability and popularity of Internet and eCommerce applications. Digital object formats do not restrict copying or further distribution of image files. Watermarking is used to assert rightful ownership or track down pirate copies by previous invisible embedding of a logo or a serial number into the file. The performance of watermarking schemes .