A METHOD OF EMBEDDING ROBUST WATERMARKS INTO DIGITAL COLOR IMAGES

It is urgently required to protect copyrights of digital contents sinc e the digital contents can be easily copied without degradation of qua lity. In this paper, we propose a new watermarking method which spread s an ID pattern with a random sequence and embeds it throughout the sp atial domain of a color image. The random sequence is a key for extrac ting the ID pattern. As an ID pattern is spread throughout an image, w e can extract the ID pattern from a part of the image, that is clipped image. We can also confirm authenticity by extracting the same ID pat tern from several parts of an image. The proposed method is robust to disturbance by noise addition and image conversion such as brightness- contrast conversion and JPEG compression.