一种基于数字水印的抗 JPEG 压缩的图像认证方法

摘要

In this article we present a JPEG compression-resistant image authentication algorithm.The coefficients relationship in regard to different block-same position will hardly change after the discrete cosine transform (DCT)is applied to the image,this property is used to extract the feature coding and then to embed the codes into the image requiring authentication after encryption.When the watermark is embedded,the characteristics of human visual system will be given full consideration,and the embedding intensity of watermarks will be regulated using the coefficients of intensity masking,texture masking and frequency masking.Authentication system will compare and analyse the feature coding of the image to be detected with the extracted watermarking information and decides according to the tamper matrix generated whether the content of the image has been tampered,and reveals the specific tampering position.%提出一种抗 JPEG 压缩的图像认证方法。DCT 变换后的图像，异块同位的系数关系基本不会发生变化，利用这一性质提取特征编码，加密后嵌入所需认证的图像中。嵌入水印时充分考虑人类视觉系统特征，利用亮度掩蔽系数，纹理掩蔽系数，频率掩蔽系数对水印的嵌入强度加以调节。认证系统将待检测图像的特征编码与提取出的水印信息比较分析，根据生成的篡改矩阵判定检测图像的内容是否被篡改，并指出具体的篡改位置。