Figure 7
Features of the pictorial layer revealed by THz sparsity-based deconvolved signals. (a) THz C-scan based on the amplitude of second peak of the deconvolved signals; (b) THz C-scan based on the amplitude of the peak corresponding to the interface between the pictorial and underpainting layers; (c) binary THz C-scan indicating the positions where delamination occurs; (d) THz C-scan based on the optical delay between the peaks corresponding to the thickness of the pictorial layer.
