Home – Home – Jornals – Avtometriya 2018 number 4

An algorithm for estimating the node coordinates of deformed lattices of quasiperiodic textures with subpixel accuracy is proposed. The algorithm consists of two steps. In the first step, the vectors of the frequencies and initial phases of a polyharmonic brightness function model are calculated from the characteristics of spectral outliers of image fragments. The obtained estimates are used to determine the coordinates of the nodes of local lattices. In the second stage, the local lattices are combined into a global lattice for the entire image of the quasi-periodic texture. Using high-accuracy estimates of model parameters from small image fragments ensures stable operation of the algorithm for significant deformations of the lattice and sub-pixel accuracy in estimating the coordinates of its nodes. Results of computer simulation and processing of real halftone images of quasiperiodic textures are given demonstrating the effectiveness of the proposed algorithm.