Using the spectral approach in image and arbitrary data processing

Abstract

Introduction: The transfer of image processing operations to the spectral region is considered. Due to the duality of information representation, coding, filtering, compression and other transformations are possible both in the space of an object and in the region of spatial frequencies, in relation to its spatial spectrum. Purpose: To evaluate the efficiency of performing image processing operations and arbitrary digital information in the spectral domain. Results: A method for spectral holographic coding is proposed, which provides a gain in noise immunity by 7–8 dB and has less complexity of coding and decoding when changing redundancy over a wide range. During the coding process, the source data block is replaced by a code word, which is a linear one-dimensional hologram of a virtual point source. For transmission over a communication channel, we synthesize a signal with a given spectrum, the shape of which is a one-dimensional hologram, with its values rounded to one bit and the hologram itself being a sequence of zeros and ones – one means the presence of the corresponding harmonic in the spectrum, zero means the absence. To create a signal with such a line spectrum, it suffices to add a set of harmonics of equal amplitude with numbers corresponding to the position numbers of the units in the hologram. This operation is one of the types of orthogonal frequency division multiplexing, characterized in that the frequencies of the orthogonal subcarriers are in a multiple ratio, and amplitude shift keying is used as digital modulation. We propose a spectral method for image compression based on a detailed analysis of the spatial spectrum of an image and the removal of a large number of insignificant areas from it. Practical relevance: The reduction in the amount of information and, accordingly, the size of the image can be 4–8 times or more with a slight decrease in image quality.