Multiple digital watermarking algorithm based on DCT and spread Spectrum

摘要

In order to improve the performance of muti-digital rights protection, a multiple watermarking algorithm based on Discrete Cosine Transform (DCT) and spread-spectrum technique is proposed. First, the host image is divided into subblock and each block is manipulated by DCT. Second, two watermarks are encrypted by Arnold scrambling. Third, the watermarks are modulated by by utilizing two kinds of strategies, and then are embedded in middle frequency coefficients of DCT domain. Experimental results show that the proposed algorithm is efficient to resist traditional signal processing attacks and has better security and robustness, higher capacity.