Collusion Attack Resistant Watermarking Scheme for Images using DCT

Image Watermarking with both insensible detection and high robustness capabilities is still a challenging problem for copyright protection up to now. This paper presents a new scheme for watermarking of still image by introducing redundancy in conjunction with low frequency coefficient, in classical middle frequency coefficients exchange scheme to make it collusion attack resistant. Experimental results show the robustness of the proposed scheme against the JPEG compression and other common image manipulations.