A Study of Embedding Digital Watermarks on a Fractal Compressed Image

• Main Authors: YANG JAN YUAN, 楊朝源
• Other Authors: 洪維恩
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/50694559766646767472

碩士 === 育達商業技術學院 === 資訊管理所 === 93 === The fractal compression technique is based on the properties of self-similarities and iterations. This technique compresses the original image into IFS, iterated function systems, which specify the coefficients of certain transformation matrix. When the images need to be reconstructed, the transformation rules are then applied to images iteratively to decompress the image. Recently, digital image watermarking is considered an efficient way to protect the ownership of digital images. The reason for this is because not only digital watermarks can efficiently protect the copyright but also can hardly be detected by human’s naked eyes. Therefore, the technique of digital watermarking are also applied to the fractal compression images in the last decade. Traditionally, when digital watermarks are hidden to a fractal compressed image, they hide a signature into IFS while searching it’s position, rotation and mapping transformation parameters. Therefore, the size of hidden information is limited. This research focus on changing another mapping transformation parameter by using smaller range blocks. This results is expected to be shown that more watermark information can be embed via this way, and without loss the capability to against some attacks