Blind detection attack resistant image watermarking

A new scheme is proposed which uses the features of Discrete Cosine Transform (DCT) for the embedding of the watermark coefficients and uses a pseudo-random sequence for selection of the DCT coefficients to embed the watermark. These coefficients are different in different watermarked images so there is no chance of collusion of the watermarked images to detect the watermark illegally. The scheme is better than the spatial watermarking algorithms such as LSB based watermarking. It is also better than the DCT mid-band scheme where the coefficients to embed the watermark are always fixed, and the watermark is embedded by simply exchanging the coefficients according to the watermark bits. Having all the properties of DCT watermarking this algorithm enhances the robustness of the watermark by involving the coefficient averaging concept. The chance of a successful attack on the watermark by an attacker is very less due to use of this averaging technique. The main advantage of the scheme is that the image is scrambled before embedding of the watermark and descrambled after embedding.