“…[
23 ] A Gabor filter is a linear filter based on this idea, and it was originally developed for 1D signal analysis. Daugman extended the Gabor filter to two dimensions(2D) and, since then, it has been found to be particularly appropriate for texture analysis, feature extraction, edge detection, image compression and a multitude of image‐related fields [
22,24–28 ] These filters are commonly described as a function produced by a Gaussian‐shaped kernel times a complex sinusoid. In a spatial domain, a 2D Gabor filter is defined as a Gaussian kernel function ( w ) modulated by a complex sinusoidal plane wave(s):
where σ is the standard deviation of the Gaussian,
and
are the variance in x ‐axis and y ‐axis and determines the width of the major and minor axis of the Gaussian envelope.…”