Texture orientation and anisotropy calculation by Fourier transform and Principal Component Analysis

This paper proposes a simple method to calculate a texture angle of orientation and degree of anisotropy. The principle of the algorithm is first to calculate the image Fourier transform modulus and then to characterise the distribution of this spectrum around the zero frequencies by Principal Component Analysis. The algorithm returns both the angle of orientation and an index of confidence. This index runs from 0% to 100% and indicates whether the texture is oriented, i.e. anisotropic, or not. This algorithm is applied to the characterisation of surface textures obtained by different machining processes. Hence, it is shown that the degree of anisotropy given by this method can be successfully applied as a characterisation parameter for surface textures.