Trellis-Based Informed Coding With Simplex and Hadamard Codes for Digital Watermarking

• Main Authors: Bo-Lin Chen, 陳柏霖
• Other Authors: 陳後守
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/22281499451293340054

碩士 === 國立中興大學 === 電機工程學系所 === 99 === Watermarking that means we embed some information in host, and make distortion of host is unobservable, and we can get the embedded complete information even if the host is influenced by channel or attack.This paper proposes a informed watermarking based on trellis structure, and combine informed coding with informed embedding .We modified parallel trellis structure in informed coding.These algorithms employ the codewords of linear block code to label the arcs in the convolutional trellis.We present two informed embedding algorithms for watermarking system. These algorithms are capable of embedding 1536 bits of message in an gray-level image of size 512x512 pixels. With this characteristic, we can easily adjust the fidelity and robustness of watermarked images by some controllable parameters. We report the robustness and complexity performance of these algorithms under the fixed fidelity in comparison with Miller''s. And we show the robustness results in Gaussian noise, lossy compression, low-pass filer and valumetric scaling. Moreover, the proposed algorithms has better BER erformance compared with Miller''s.