为权衡水印技术的鲁棒性和对篡改敏感性的冲突，本文提出了在载体图像中嵌入鲁棒水印和全脆弱水印的双重数字水印方案。首先对水印图像进行了置乱和加密，并对得到的加密水印进行了扩频处理。接着在混合变换域内实现了对加密扩频水印的嵌入：先对图像载体进行小波变换和离散余弦变换，通过修改各块的部分余弦系数的差值实现水印信息的嵌入。提取时实现了盲水印提取。实验结果表明，该算法具有很强的安全性和不可见性,对抗噪声和剪切攻击具有良好的鲁棒性。

In order to balance the collision between the robustness and the sensitivity tampering of the watermarking technology, a dual digital watermarking scheme which embeds robust watermarking and fragile watermarking into the carrier images is proposed. A scramble operation and encryption to watermarking images are first prosecuted.A spread spectrum technique is used in the encrypted watermarking. Then, we embed an encrypted spread spectrum watermark into the hybrid transform domain: the experiment first performs discrete wavelet transform and discrete cosine transform to the carrier image, and then embeds the  watermarking message by changing part of each block DCT coefficient .The receiver realizes blind watermarking extraction. The experimental results show that this algorithm possesses better secrecy and invisibility, and has good robustness to noise and cropping attacks.