Fig. 1. Schematic diagram of ILMD measurement

Fig. 2. Flow chart of correction method of ILMD

Fig. 3. Schematic diagram of ILMD structure

Fig. 4. Schematic of structure and prototype of ILMD

Fig. 5. Visual matching function filter and its spectral response

Fig. 6. Linear correction curves of ILMD

Fig. 7. Reference images for flat-field correction

Fig. 8. Contrast images before and after flat-field correction

Fig. 9. 15 pieces of checkerboard calibration target image data