UDC 004.932
METHODS OF MASKING AND RESTORING IMAGES
K. I. Vasiliev, post-graduate student, RSREU, Ryazan, Russia;
orcid.org/0009-0009-8551-8530, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
A. I. Novikov, Dr. in technical sciences, associate professor, full professor, department of electronic compu ting machines, RSREU, Ryazan, Russia;
orcid.org/0000-0002-8166-8234, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
When transmitting information over open communication channels, it is often necessary to conceal this information without using special encryption methods. The simplest methods are based on blurring the orig inal image using a linear filter with a properly selected transformation core (mask). On the receiving side, with this approach, it becomes necessary to restore masked information. The task of restoring blurred sig nals belongs to the class of incorrect tasks. Neglecting transformation core by third parties and the need to use sufficiently complex mathematical apparatus to restore information on the receiving side create condi tions for more reliable concealment of official information. The article discusses two approaches to masking and, accordingly, to information recovery. In the first case, blurring is performed on transmitting side and restoration on receiving side using either a regularization algorithm or an iterative method. In the second approach, a direct discrete Fourier transform (DFT) of original signal is performed first. Then the matrix of coefficients of forward DFT is blurred. On the receiving side, information recovery is performed in two stag es in reverse order. The results of experimental studies of information masking and recovery with each ap proach are presented.
Key words: : mathematical methods, linear and nonlinear operators, affine and projective transfor mations, interpretation of indirect measurements, complex contour analysis.