A New Semi-fragile Watermarking Algorithm Based on Image Content
一种基于图像内容的半脆弱数字水印算法

A new chaos-based semi-fragile watermarking algorithm is proposed in this paper, which first divided the total image into two parts of same size in pixel numbers, one part is used to extract image features which will be used watermarking, the other part is used to embed the watermarking extracted from the first part. The watermarking is embedded in the coefficients of low frequency of wavelet transform, and the watermarking can be extracted without resorting to the original host image. The correlation between the original watermarking and that of extracted and between the original waterrnarking and that of feature extracted from the watermarked image are used to distinguish the sort of distort imposedon image, and thetampered area of watermarked image can be reflected. Experimental results show that algorithm is robust to noise adding, compress and effective to differentiate occasional distortion from malicious tamper.