提出了一种基于DCT-DWT的彩色图像全息水印算法。为了保证水印信息的安全性，该算法首先对水印信息进行双随机相位调制，并生成水印全息图；其次，将载体图像在Lab空间内的L分量进行4×4分块，对每一分块进行DCT变换，抽取每个矩阵的中低频系数，组成一个新的矩阵，并对之进行小波分解，将水印全息图嵌入到它的中低频小波系数上。实验结果表明，基于DCT-DWT变换的水印算法具有较好的不可见性，对常见的攻击具有强鲁棒性。

A color image holographic watermarking algorithm based on DCT-DWT was proposed. In order to ensure the security of watermark, the watermark information was modulated by double random phase plates and generated into a hologram watermark; meanwhile, the carrier image's L vector in Lab space was partitioned into 4 × 4 blocks, which were transformed by DCT. The low frequency components were extracting from each matrix to form a new matrix, which was decomposed by DWT. The holographic watermark information was embedded into the low-frequency wavelet coefficients. Experimental results showed that the watermarking algorithm based on DCT-DWT is invisible, and robust to common attacks.