Digital image watermarking in wavelet domain based on FSK modulation

In this paper a new image watermarking algorithm based on the FSK modulation in wavelet domain is proposed. Two dimensional FSK modulator produce proper pattern due to the level and the direction of each subband. These patterns are locally inserted in each subband by spread spectrum and substitution techniques. Local properties of image in wavelet domain including edges and busy textures are used for adaptive watermarking to improve the robustness. This algorithm is suitable for blind detecting the watermarked data and doesn't need the coupling parameter either. The results show that the algorithm is robust for the image processing attacks such as adding noise, low pass and median filtering, scaling and cropped image.