Home – Home – Jornals – Avtometriya 2020 number 6

Wavelet filtering algorithms are widely used for image processing, and most of these algorithms are of a threshold nature: the wavelet expansion coefficient whose absolute value is smaller than a certain threshold value vanishes; otherwise the coefficient undergoes some (most often nonlinear) transformation, which is defined by the threshold function used. When high-contrast images are filtered, such processing of expansion coefficients can lead to the emergence of the so-called artifacts in the filtered image - in the vicinity of a jump-like change in the amplitude of the filtered image, there appear pulses that are absent in the original image, which significantly degrades the filtering quality. To eliminate such artifacts, several approaches are considered in the present paper, and a method is proposed, which implies post-processing of the results of wavelet filtering of images by nonlinear algorithms of spatial filtering. The computational experiment is performed, which makes it possible to conclude that the proposed method is an effective way to eliminate artifacts of wavelet filtering of high-contrast images.