A shift-resisting public watermark system for protecting image processing software

Digital watermark is a technique used to protect the ownership of images and their associated software. A useful watermark scheme should be visually imperceptible and must be robust to resist various attacks: such as JPEG compression, pixel-shifting, cropping, blurring, etc. In this paper, we propose a public watermarking system to protect image processing software and images. We embed a binary image as watermark in DCT domain, and the watermarked image is imperceptible by human visual system and robust to image shifting or cropping. We use feature-based approach to synchronize the watermark positions during embedding and extracting. For better image quality, the more complex in a block, the more bits can be embedded. Our approach doesn’t need the original image for watermark extraction, which is a useful feature in protecting software applications such as real-time generated panorama images.