Fig. 1. Schematic diagram of RTI shooting method

Fig. 2. Reflective ball

Fig. 3. Schematic diagram of light source direction solution

Fig. 4. Normal vector of object surface^[6]

Fig. 5. Normal vector information stored in the RTI image^[6]

Fig. 6. Ordinary photographic image of handwriting

Fig. 7. RTI normal image of handwriting

Fig. 8. Oil on canvas texture visualized in RTI. (a) Plane light; (b) diffuse reflection gain; (c) specular reflection enhancement ^[9]

Fig. 9. Comparison of digital micrograph and RTI image rendered with diffuse gain. (a) Digital micrograph; (b) RTI image rendered with diffuse gain ^[19]

Fig. 10. Ordinary photographic image and RTI normal image of a pair of star gears^［23］