An image forensic method based on coefficient-pair histogram of differential DCT coefficient was proposed.In the method

the image is firstly transformed by DCT

and then the differential DCT coefficient of four directions

such as horizontal direction

vertical direction

diagonal direction and the second diagonal direction are computed.After that

the coefficient-pair histogram for each differential DCT coefficient is calculated.Finally

support vector machine (SVM) is used to classify the authentic and spliced image through training the feature vectors of authentic and that of tampered image.The experimental results show that the proposed approach not only has low computing complexity

but also outperforms all the state-of-the-art methods in detection rate on the same test database.