“…The algorithm is based on multilevel thresholding of RGB images resulting from C-Scan testing with correlative displacement of gradient fields associated with damaged areas of composite structures. Using the proposed algorithm an extraction of damage visualization from a C-Scan image is carried out (Atta and Abdel-Kader, 2015;Xu et al, 2015;Singh et al, 2015;Guo et al, 2018;Lee et al, 2017;Furnari et al, 2017;Huang et al, 2015;Iskandarani, 2018).…”