FIELD: information technology.
SUBSTANCE: invention relates to the field of information technology, namely to verifying the authenticity of images of documents of various types. The method for detecting and localizing the falsified area in JPEG images consists in the fact that the image is considered in the RGB color space, which was subjected to JPEG compression, after which, with the help of software, falsifications were performed and the modified image was saved in a lossless format, while the detection of the falsified area is based on the search for inconsistencies in structure of DCT coefficients of JPEG images, to do this, the DCT coefficients of the image are calculated with saving the information about the position of the blocks corresponding to the coefficients of 8 by 8 pixels, the quantization matrix is evaluated according to the calculated DCT coefficients, while the image is divided into several blocks, then the quantization step is estimated for each of the 64 frequencies in each block, the JPEG compression grid position is searched, the image is searched for inconsistencies of DCT coefficients to the quantization matrix, the falsified areas are localized.
EFFECT: increase in the accuracy of determining the falsified area in the image.
1 cl, 7 dwg
