An improved robust image watermarking method using DCT and YCoCg-R color space

Watermarking is one of the solutions to prevent unauthorized use of digital media. This solution can help the protection of ownership rights by embedding the copyright information in the intended media. In this paper, a digital image watermarking algorithm in YCoCg-R color space is proposed. Thriplet components of YCoCg-R color space have a good decorrelation and changing one component has the least impact on the two other color components. So it can be effective in increasing the robustness of watermarking against various attacks. For watermark embedding the proposed method uses Discrete Cosine Transform and its coefficients relationship. During watermark bits embedding, complexity amount of host image blocks is utilized to select the target blocks and energy value of host image blocks is used to adaptive selection of embedding strengths that it causes a very high robustness especially against JPEG compression. The Arnold transformation, also, plays an important role in increasing the security of our proposed method by scrambling the watermark. Considering the conflict among three main requirements of watermarking, including imperceptibility, robustness and capacity, the proposed method is compared with other algorithms and the results show the superior robustness of the proposed method over the other algorithms with same capacity. (c) 2017 Elsevier GmbH. All rights reserved.