Computer Diffraction Tomography: A Comparative Analysis of the Use of Guided and Wavelet Filters for Image Processing

Digital processing of 2D X-ray projection images of a Coulomb-type point defect in a Si(111) crystal detected against the statistical Gaussian noise background has been carried out using a guided filter and a wavelet filter with the 4th-order Daubechies function. The efficiency of 2D image filtering has been determined by calculating the relative square deviations of the intensities of the filtered and reference (noise-free) 2D images averaged over all points. A comparison of the calculated relative root-mean-square deviations of the intensities has shown that the investigated methods work quite well and can be effectively used in noise processing of X-ray diffraction images for 3D reconstruction of nanoscale defects in crystal structures.