A robust image watermarking scheme based on normalized circular image in DWT domain

In this paper, a wavelet based image watermarking scheme for copyright protection is proposed. In order to reduce the effect of synchronization errors caused by geometric attacks such as rotation, the watermark is embedded into rotation normalized circular image, which is obtained from the host image. The embedding of the watermark is carried out by modifying the two largest coefficients values in selected blocks. The extraction process does not require the original image. Experimental results show that the proposed scheme successfully makes the watermark perceptually invisible as well as robust to common signal processing and some geometric attacks including JPEG compression, filtering sharpening, rotation and scaling attacks.