An HVS Inspired Robust Non-blind Watermarking Scheme in YCbCr Color Space

Abstract

Digital Watermarking is an important tool for copyright protection. A good quality watermarking scheme should provide both perceptual transparency as well as robustness against attacks. Many efficient schemes exist for grayscale image watermarking, but relatively less attention has been paid to watermarking for color images. Moreover, the existing works do not provide adequate justification for the possible choice of color space. In this paper, justification is provided for the choice of YCbCr color space for watermark embedding. A human visual system (HVS)-inspired image-adaptive non-blind watermarking scheme in the YCbCr space has subsequently been proposed. This new algorithm has been referred to as the Additive Embedding Scheme (AES). It comprises of a modified watermarking strength parameter ([Formula: see text]), in combination with the discrete wavelet transform and singular value decomposition (DWT-SVD). Experimental results demonstrate that the proposed watermarking scheme in YCbCr color space provides better perceptual quality as well as robustness against attacks as compared to existing schemes. We have further improvised the aforementioned scheme to come up with a Multiplicative Embedding Scheme (MES) for additional robustness against a special type of attack, viz. the Singular Value Exchange Attack.