Robust Watermarking into the Color Models Based on the Synchronization Template

Image watermarking has become an important tool for intellectual property protection and authentication. In this paper a watermarking technique is suggested that incorporates two watermarks in a host image for improved robustness. A watermark, in form of a PN sequence (will be called the information watermark), is embedded in the DCT domain of the cover image. The second watermark (called synchronization template) is then embedded in the already watermarked image. Synchronization template does not contain any information and is used only to detect and correct any geometrical changes came after the attack on the image. The Watermark is embedded on the two color models, RGB and YCbCr. The effect of the dual watermark on each component of the color models is analyzed and its performance is studied vis-a-vis scaling attack.