A shift-resisting blind watermark system for panoramic images

The 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. We propose a new watermarking technique that achieves the prescribed goals. We add synchronization bits to maintain the correct position information of the original 8/spl times/8 DCT block during the extracting phase. To avoid cropping some part of image and losing watermark information, we add watermark bits according to the edging features of each block. Therefore, the proposed approach needs neither the original image nor the original watermark pattern for watermark extraction, which is a useful feature in protecting real-time generated panorama images.