Robust Watermarking Method using QIM with VSS for Image Copyright Protection
This paper proposes a new watermarking method for digital image by composing the DWT-QIM based embedding with visual secret sharing (VSS) method. Firstly, the watermark image is separated into $n$ shares by using the $k-out-of-n$ method, called $(k,n)$ visual secret sharing. One of share is employed in order to embed into the original image for copyright protection. Another $(n-1)$ of shares are registered with Vietnam Copyright Department. When the dispute happens, the verifier can extract the watermark information from the watermarked image, then, decode it with $(k-1)$ shares chosen from $(n-1)$ shares to achieve the copyright information. Our experimental results show that our proposed method works efficiently on the digital images.