JEPG format of images is the most widely used image format in people’s daily life, so the tamper detection on this kind of image has a more important significance.Under the theoretical basis that the tampered area in the compressed JPEG image is equivalent to one compression, the basic principles of one and double compressed JEPG image were researched. The influence of the size of relationship between quality factorsQ1andQ2on the histogram of DCT coefficients of the double compressed image was analyzed, and two cases were carried out to find its histogram by the image block DCT coefficients. Then different methods were used to determine whether the image block was compressed once or twice. Finally, image tamper detection algorithm for JPEG image based on DCT coefficients histogram was proposed. Experiments showed that the algorithm is not only low computational complexity, but also has a good detection and location results.
