A PCA-DWT-SVD based color image watermarking

A robust color image watermarking scheme is proposed, in which a color watermark is embedded into a color image. Principle component analysis is used to uncorrelate the R, G and B channels of both the images. Each channel of color watermark is embedded into singular values of corresponding channel of cover image after discrete wavelet decomposition. As original image is required at the time of extraction of watermark so given scheme is non-blind. Peak signal to noise ratio is used to measure the imperceptibility whereas similarity between original and extracted watermark is measured using normalized correlation coefficient. The scheme was tested against various attacks (including histogram equalization, Gaussian noise, cropping, Y-shearing, X-shearing, affine transformation, salt & pepper), to check the robustness. The results of proposed scheme are compared with existing color watermarking schemes. The results show that proposed scheme is robust and imperceptible.