Robust watermarking for digital imagery based on SVD transformation

• Main Authors: Yung-Zhi Wu, 吳永智
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/82080189111431292043

碩士 === 國立雲林科技大學 === 電機工程系碩士班 === 91 === Because the wide-spread use of computer network, circulation of digital image becomes very easy nowadays. However, digital imagery has the property of repeating copy without losing quality and therefore is prone to pirate. Current common strategy of protecting the ownership is by inserting watermark into the image. There are two categories for the insertion process: one is spatial domain based, and the other is frequency domain (DCT) based. In order to help the identification of ownership, one good watermarking system should have the capabilities of imperceptibility to human eyes and robustness to various attacks. Currently, most of the watermarking techniques published do not have complete tests to verify their robustness to attacks. In this paper, we proposed a new method called C-SVD, and conducted various attacks to evaluate its effectiveness. Compared with other techniques, the new method proved to be the most robust under all the attacking tests.