一种针对彩色图像的泛盲掩密分析方案

A Universal Blind Steganalysis for Color Images

基于Farid(2002)年泛盲掩密分析算法对彩色图像检测的局限性,提出了新的泛盲掩密分析算法。该算法利用彩色图像的亮度和色度进行分类特征矢量的选择。通过矢量方向滤波技术(VDF)对图像进行方向化处理,并以滤波前后图像之间的矢量方向相关度为色度的分类特征。该方法大大减少了分类特征的数目,而且克服了Farid算法忽略RGB3个颜色通道间相关性的缺陷。分别利用该算法和Farid的算法对JSteg,F5和EZStego软件掩密后的图像进行检测,比较实验结果表明,对于不同长度的嵌入消息,该算法具有更好的检测性能。

On the basis of the limitation of Farid＇s universal blind steganalysis for color images, a new universal blind steganalysis scheme is proposed. In view of the luminance and the chrominance of the image, the class feature vector is extracted. A new approach is presented to extract the feature for the chrominance component that the image is directional processed using the vector directional filter, and then the vector direction correlation between the image and its directional filtered image is calculated. It reduces the number of the features enormously, and overcomes the fault of Farid＇s scheme that neglects the inherent correlation between the RGB channels, which is propitious to simplify the design of classifier and to improve the performance of the classifier. Applying the scheme and Farid＇s scheme to detecting the stego images produced by JSteg, F5, and EZStego respectively, the comparison of these simulation results shows that the scheme is quite more efficient for different size of messages embedded.