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Digital forensics is a field of knowledge that is currently actively developing. The challenges facing digital forensics often intersect with mathematical methods for finding traces of violations of the integrity of digital images. Photomontage, application of filters and other violations of the integrity of digital images are possible thanks to graphic editors with a large number of tools, in particular - filters for artificial sharpening. Graphic editors such as Gimp or Adobe Photohsop will allow users to perform various image manipulations and other digital media files, even without special training. Little attention has been paid in open printing to the problem of detecting violations of the integrity of digital images in the form of filter processing, in particular, sharpening filters. The aim of this work is to improve the detection efficiency of digital image processing by modifying the method of detecting sharpening. It has been observed that a large number of pixels with a value of 0 appear in the digital image matrices under the influence of the artificial sharpening filter. This effect is called the "black effect". The paper analyzes the parameters of the digital image and the black effect, which allowed to modify the method of detecting artificial sharpening of digital images. As a result of the work, the method of detecting artificial sharpening of digital images was modified. The original method was tested for digital images in a lossless format. The performed modification was checked both for the images saved after processing by the filter in a lossless format, and with losses. When testing the method, the number of errors of the first kind was 8%, the second kind - 10% for digital images saved after falsification with loss, and 4% and 7% respectively for digital images saved after falsification in lossless format. [ABSTRACT FROM AUTHOR]

The use of the digital images in modern society is very common, making it difficult to name an industry where digital images are not used. However, in certain situations, the digital images may be direct or indirect digital evidence, such as in court cases. Tampering or violating the integrity of the digital images is one of the important issues in the information protection. The issue of the digital signal authentication by cybersecurity experts is a pressing issue in the present days. Therefore, the development of methods and algorithms for detecting the integrity of digital signals in general, and digital images in particular, is a very crucial task. Among all the possible variations in the integrity violation of digital images can be distinguished a separate group, in which the digital images are processed by various filters editors, such as blurring, sharpening, etc. The blurring is often applied to images not only when they are tampered, but also as a steganographic attack. Blur detection indicates the inability to use a digital image as the evidence of anything. One of the most effective blur detection methods known from the open sources is a method based on the analysis of singular values of blocks of a digital image matrix. The aim of this paper is to increase the efficiency of the blur detection in a digital image by modifying an algorithm based on the analysis of singular values. Computational experiments are performed to determine the number of parameters to be verified. The results obtained allow modifying the algorithm of the method of the blur detection in a digital image. The modification makes it possible to detect tampered access to a digital image. The modified algorithm is no less effective than the original algorithm, and allows analyzing fewer parameters in a shorter time. The computational complexity of the algorithm is determined by the second order polynomial that is acceptable in terms of the practical application. [ABSTRACT FROM AUTHOR]

Modern information protection issues are changing with the development of information technology. Every year, the level of cybercrime is getting higher everywhere. Often cybercriminals are exposed to digital files of various formats. One of the main tasks of modern information security is the detection of violations of the integrity of digital signals, in particular, digital imaging. Detection of digital image processing is currently a topical task due to the increased incidence of integrity of important documents. Digital images are almost always processed by the filters of graphic editors. One of the popular filters is the sharpening. In the open edition, a single algorithm for detecting artificial sharpening was found. The existing algorithm is based on the analysis of close pairs of colors of a digital image in relation to the total number of pairs of colors of the matrix of a digital image. Threshold value is detected, considering what certain ratio of these indicators indicates presence or absence of sharpening. However, his main disadvantage is a large number of errors of the first and second kind. In this paper, the influence of the partition of the image matrix on square blocks of different sizes on the effectiveness of detecting sharpening is investigated. As a sharpening filter, Adobe Photoshop's Intelligent Sharpness tool is chosen because of its wide-ranging popularity. On the basis of the conducted research modification of the algorithm was performed. This modification made it possible to reduce the number of errors of the 1st kind by 12%, and the 2 genera by 4%, which results in 40% of errors of the second kind and 14% of errors of the 1st genus. Also, possible further variants of development and improvement of the process of detection of the indicated processing, namely, the study of the influence of the modification of the formula of close pairs of colors on the efficiency of the algorithm, are proposed in the work. [ABSTRACT FROM AUTHOR]

In this paper it is proposed basics of a new approach to identify cloning results, conducted in digital images, in additional disturbing influences conditions in a digital image after cloning, that may be considered as lossy compression, add noise, blur, etc. The approach is based on identifying the comparability of the surface parts, which is put into correspondence the analyzed image appropriate clones and its preimage. The surface is determined by the graph of the interpolation spline, approaching the function of the image, and the elements of the image are regarded as the interpolation nodes. It is proved that as the main quantitative characteristics of such comparability is advisable to use the volume of a cylindrical body with generator parallel to the axis OZ, bounded from above corresponding part of the interpolation function graph, bounded below - plane XOY. [ABSTRACT FROM AUTHOR]