Method of photomontage detection under conditions of limitations absence for photos falsification

V.V. Zorilo, Ye.Yu. Lebedeva, M.O. Kozina, D.S. Belush. Method of photomontage detection under conditions of limitations absence for photos falsification. The widespread using of fake pictures in information wars, lawsuits, politics, etc., needs to develop new detection methods of photomontage. One of them is a method of photomontage detection based on the analysis of singular values of matrix blocks of digital images. Aim: The aim of this research is to check the application area of photomontage detection method based on analysis of singular values of matrix blocks of digital images in the absence of restrictions on the degree of their compression. Materials and Methods: The basis of this method is the detection of the differences between the images when they have different degrees of compression: values of the zero singular values matrix of blocks corresponding to foreign part of image. We distinguish this area on the background of the main image, that allows to detect falsification. The mentioned method was investigated under certain restrictions imposed on the used test photos. An advanced experiment with images was held, for which there are no restrictions on the degree of compression. Results: The falsification was detected in 44.4% of cases in experimental study while saving the digital image after photomontage in lossless format, and in 53.3% of cases when saving the losses. Montage was detected most often when the difference between the quality factor Q of the main image and the replacing area was more than two. Keywords: photomontage, digital image integrity checking, photomontage detection method, digital image matrix, singular numbers. [TEXT NOT REPRODUCIBLE IN ASCII]