Optical image watermarking based on singular value decomposition ghost imaging and lifting wavelet transform

Abstract

An optical image watermarking method based on singular value decomposition ghost imaging (SVDGI) and a blind watermarking algorithm is proposed. The watermark image is first encrypted by an SVDGI system, then the encrypted watermark is embedded in the host image with the help of the watermark algorithm, which uses the block discrete cosine transform (DCT) and integer lifting wavelet transform (LWT). The proposed watermarking algorithm has good imperceptibility and robustness, and no original host image is needed when extracting the watermark. SVDGI provides a new reconstruction method in ghost imaging (GI) by modifying the measurement matrix with the help of singular value decomposition, which carries out the reconstruction process in less time and at higher quality. The measurement matrix composes a secret key, and only with this key can authorized users decrypt and reconstruct the original watermark image. Both optical experiments and numerical simulations validate the feasibility of the proposed method.