此工程实现提取jpeg图像的DCT系数首字母概率作为jpeg重压缩检测的特征，以此特征训练出分类模板，可以检测出一张jpeg图像是单压缩还是重压缩。-Works to achieve this extract jpeg image DCT coefficients of the first letter of the probability of detection as a jpeg heavy compression feature, this feature trained classification templates that can detect a single jpeg image compression or recompression.