Fig. 1. Model of the ink mark sample

Fig. 2. Schematic of the SSOCT system

Fig. 3. Ink mark samples used in the calibration experiment and the measured OCT images and their axial scan signal. (a1) Sample of Deli ink mark; (a2) sample of PILOT ink mark; (a3) sample of Hero ink mark; (b1) and (b2) OCT image of a white paper and the axial scan signal corresponding to the line in the Fig. 3(b1), respectively; (c1) and (c2) OCT image of Hero ink mark and the axial scan signal corresponding to the line in the Fig. 3<

Fig. 4. Normalized intensity data and the fitting curves of the different brands of ink mark and the white paper. (a) Normalized intensity data; (b) normalized fitting curves

Fig. 5. Photograph and the OCT images of the handwriting sample. (a) Photograph of the handwriting sample written using the three kinds of ink; (b) OCT intensity image of the handwriting sample; (c) false color image of the handwriting sample reconstructed using the proposed method