【摘要】 提出了一种用于图像内容认证的半脆弱水印算法。该算法利用小波变换模极大值提取图像边缘特征,并结合经混沌映射后的小波低频域特征信息生成两个水印。一个主要用于篡改定位,另一个主要用于检测图像的内容篡改。水印嵌入在小波变换的中频域中。水印提取和认证不需要原始水印信息,提高了水印安全性。实验表明,该算法能有效区分偶然失真和恶意篡改,并能定位出篡改发生的位置。更多还原

【Abstract】 A semi-fragile watermarking algorithm for image authentication is proposed.Edge-character is extracted by finding the maxima of a wavelet transform modulus.Low frequency character is generated by wavelet transform for another watermark.One watermark is used for indicating the modified location and another is used for checking content modification.Watermarks are embedded in the coefficients of middle frequency of wavelet transform.Image authentication and watermark extract need no information about the original watermark.Experimental results show that the proposed algorithm provides good classification of intentional and incidental tampering.更多还原