Wavelet domain geometrically robust image watermarking algorithm based on normalization

A new image watermarking algorithm based on normalization in wavelet domain (WNWD) robust to geometric attacks is presented in this paper. In the algorithm, watermark embedding and detecting are implemented in normalized domain. 9/7 biorthogonal wavelet is adopted to decompose the image and the watermark is embedded by modifying wavelet coefficients. When detecting, watermark is extracted by comparing wavelet coefficients without the original image. Experimental results show that WNWD algorithm can efficiently resist rotation, scaling and common signal processing attacks, such as JPEG compression, added noise and filtering.