Growing demands for high reliability of constructions made of composite materials lead to a significant development of non-destructive testing methods of structural diagnostics. Among the most accurate and sensitive techniques used for analysis of internal defects, is the computed tomography (CT). However, since the results obtained from CT are highly precise, certain problems with their interpretation occur. The visual information about defects has isotropic character, thus it is not possible to evaluate directions of propagation of defects. The following study presents an investigation on a problem of identifying the directionality of delaminations evolution in layered composites. The tests were performed on specimens made of polymeric composites with delamination resulted from water-jet cutting. The images of cross sections of specimens were acquired by CT scanning. In the paper, the developed algorithm based on wavelet and Hough transforms as well as other methods of image processing and analysis is presented. The proposed method allows for automatic detection of directionality of dela minations and could be applied in quality control of composite components as well as non-destructive testing during their operation.