Robustness Investigation of Digital Watermarking Algorithm for Print-and-Scan Process
Yang Yi-xian · Acta Scientiarum Naturalium Universitatis Sunyatseni · 2004
A novel digital watermarking algorithm for print_and_scan process is proposed. The key of this algorithm is its strong robustness. First, the effect of printing and scanning for images is discussed. According to the characteristic of the effect, the digital watermarking is embedded on the DCT domain of images. Especially, the DCT coefficients are classified by their position. After classify, the digital watermarking is expressed by the count of difference between the positive and the negative in each group, and the robustness is enhanced. Then, the relation among the position, robustness and intension is studied in detail. Since this algorithm is robust for printing and scanning, it can also be used in copyright and authentication purposes of digital image for the printed format.