Robust image watermarking algorithm using DCT coefficients relation in YCoCg-R color space

In this paper, a digital image watermarking method in YCoCg-R color space is proposed that uses YCoCg-R color space as a new working environment and coefficients Relation for watermark bits embedding. In the proposed algorithm, in order to pseudo-random selection of the blocks to watermark embedding and spread the distortions of watermarking, the Y channel of the host image is scrambled by Arnold transformation. Then in order to increase security against noise and cutting attacks, every bit of watermark is embedded in three different blocks. So in case of distortion in one block, the two other blocks can be the decision references for the watermark bits correct recognition in this way: a similar position in three different blocks are selected and corresponding coefficient in selected position is compared with DC coefficient in the same block. Then a distance in the amount of (a) is created between these two values based on the corresponding watermark bit. The results of evaluation and comparison with other algorithms show that the proposed method has high resistance against various attacks.