Research on double protection of semi-blind color digital watermarking algorithm
双重保护的半盲彩色数字水印算法

This paper focused on the study of semi-blind color watermarking algorithm based on the combination DWT with SVD. In consideration of the practicality of embedding watermark, the original image and watermark image all used color pictures. In scrambling transformation and semi-blind watermarking double protection, enhanced the security of watermark. Because SVD was steady towards the common geometric distortion, and with using DWT, the main energy of image occupied the low frequency domain. It was better to improve the resistance to attack of watermark by combining with the advantages of DWT and SVD. The result demonstrates that after the watermark image subjected to the attacks of adding noise, filtering (such as obscuring and sharpening), scaling, rotating, cutting and loss compression, the extracted watermark also has high similarity and peak signal to noise ratio with the original watermark. The algorithm is robust.