A Novel Color Image Watermarking Algorithm Based on Digital Signature

A novel color watermarking algorithm based on digital signature is proposed. First, the color host image is split into red, green and blue components. Discrete Wavelet Transform level-3 is performed on blue component to obtain various sub-bands. Next, the cD2 sub-band is decomposed by Singular value decomposition, and the watermark information is embedded into the singular values. Then, the digital signature of the orthogonal matrices is generated, and the digital signature is embedded into subbands cH3 and cV3. Last, a set of common attacks are imposed on the watermarked image to test the performance of the new algorithm. The experimental results show that the new algorithm obtains outstanding imperceptibility and robustness compared to the previous algorithms. Meanwhile, the security of the new algorithm catches a higher level by combing digital signature.