The Study of Copyright Protection Schemes for Digital Images

• Main Authors: Jyh-Chiang Yeh, 葉志強
• Other Authors: Chin-Chen Chang
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/49685967027313127931

碩士 === 國立中正大學 === 資訊工程研究所 === 89 === Due to the recent growth of digital multimedia transmissions on the network, the need for the intellectual property right protection of information processed via multimedia, like images, music, and videos, has become more and more important than before. In this thesis, we propose two novel schemes for intellectual property right protection of digital images. In the first scheme, a DCT-based method for casting a binary watermark into a gray-scale image to identify the ownership of the image is described. Instead of actually hiding a watermark in a gray-scale image, we merely combine the vital features extracted from the gray-scale image with the binary watermark to be cast for achieving the purpose of copyright protection. In the second scheme, another copyright protection scheme based on visual cryptography and discrete cosine transform for color images is discussed. In this method, all we need to do is construct an ownership share according to a master share created from the color image by applying discrete cosine transform plus a color watermark used for copyright certification. By stacking the master share and the ownership share together, the watermark for ownership identification can be revealed through the utilization of visual cryptography. With substantial experimental results, the robustness of our schemes can be demonstrated upon various image processing.