Robust Copyright Protection Technique with High-embedding Capacity for Color Images

Copyright violation issues have a growing impact on applications of the digital era, especially images. It is not easy to guarantee the copyright protection of essential information. This paper presents a robust copyright protection technique with high embedding capacity for color images. The technique first fuses the multi-focus images using non-subsampled contourlet transform (NSCT) to ensure that the fused image have rich information than a single image. Further, hash value of the cover media is computed for authentication purposes. The fused image and hash value of the cover is then embedded into the cover media with the help of transformed-domain schemes. To achieve higher security, we apply an encryption scheme on fused media watermark before embedding into the cover. Lastly, a hybrid optimization algorithm is employed to compute an optimal factor, which makes a good imperceptibility and robustness at the same time. We demonstrate that the proposed technique is effective and resistant to common attacks on image datasets. Compared to existing works, this work increases the 9.5% robustness, 8.8% quality with high embedding capacity.