Removable visible image watermarking algorithm in the discrete cosine transform domain

Abstract. A removable visible watermarking scheme, which operates in the discrete cosine transform (DCT) domain, is proposed for combating copyright piracy. First, the original watermark image is divided into 16 16 blocks and the preprocessed watermark to be embedded is generated by performing element-by-element matrix multiplication on the DCT coefficient matrix of each block and a key-based matrix. The intention of generating the preprocessed watermark is to guarantee the infeasibility of the illegal removal of the embedded watermark by the unauthorized users. Then, adaptive scaling and embedding factors are computed for each block of the host image and the preprocessed watermark according to the features of the corresponding blocks to better match the human visual system characteristics. Finally, the significant DCT coefficients of the preprocessed watermark are adaptively added to those of the host image to yield the watermarked image. The watermarking system is robust against comp...

• Type: Journal
• Year: 2008
• Where: JEI
• Authors: Ying Yang, Xingming Sun, Hengfu Yang, Chang-Tsun Li
• Keywords: Embedded Watermark, Images, JEI 2006, JEI 2008, Preprocessed Watermark