The features of the (m,m) implementation scheme of visual cryptography are considered, which differs from the existing ones by the formation of shadow images (shares) of an image containing a secret. The proposed approach is based not on the decomposition of the secret image into shares, but on their step-by-step transformation by multiplication by orthogonal Hadamard matrices. The images obtained during each transformation of the stock are noise-resistant in the data transmission channel.

Keywords: image with a secret, image decomposition, image transformation, orthogonal Hadamard matrices, two-way matrix multiplication, noise-resistant image encoding

The application of orthogonal matrices in information processing and transformation systems is considered. A method is proposed for assessing the results of protective masking of audio information using Walsh-structured quasi-orthogonal Mersenne matrices.

Keywords: orthogonal matrix, message masking, masking/unmasking algorithm, amplitude-frequency response, white noise, root mean square error, signal-to-noise ratio

The issue of using the screen of an aircraft's collimator system as a means of providing a help to the pilot about the vertical profile of the flight path in poor visibility conditions at low and extremely low piloting altitudes is being considered.

Keywords: low flight altitude, extremely low flight altitude, threat of collision, collimator, virtual elevation map, virtual reality, augmented reality, artificial intelligence, data fusion, pilot assistance system

The search for orthogonal and quasi-orthogonal matrices is considered as a sequence of setting initial conditions, choosing an implementation method, filtering a set of generated sequences. It is proposed to accelerate the search for matrices by pre-fixing their structure and filtering the generated sequences using the Fourier spectrum. Fixing the structure involves using the symmetry properties of the desired matrices. Filtering allows you to exclude sequences with explicit spectrum outliers when forming blocks of symmetric matrices.

Keywords: mining of matrices, Hadamard matrices, Propus conctruction, filtering sequences

The issue of changing scientific interest in the methods of combining images in technical systems is considered. The material is based on the analysis of open publications, patents presented in the scientific electronic library eLibrary for the period 1980 – 2021, as well as not included in it for any reason. The types of sources for formation of image, goals and features of the most common ways of combining are considered. The areas of preferential use methods of combining are given. The issues of image preprocessing to increase the informativeness of the result of the combination are considered.

Keywords: visual data, foundation image, image combination, information combination, image preprocessing