Fig. 1. Schematic of initial value selection for iterative calculation

Fig. 2. Spectra of true dual-energy CT system. (a) Low energy spectrum; (b) high energy spectrum

Fig. 3. Projection lookup table images of true dual-energy CT system. (a)(b) Before optimization; (c)(d) after optimization

Fig. 4. Spectra of pseudo dual-energy CT system. (a) Low energy spectrum; (b) high energy spectrum

Fig. 5. Projection lookup table images of pseudo dual-energy CT system. (a) Carbon; (b) aluminum

Fig. 6. Gray scale curves of projection lookup tables of pseudo dual-energy CT system. (a) Carbon; (b) aluminum

Fig. 7. Schematic of calibration scope optimization for dual-energy projection

Fig. 8. Linear attenuation coefficient curves of iron and copper

Fig. 9. True dual-energy projection curves of iron and copper

Fig. 10. True dual-energy projection curves of copper

Fig. 11. Projection lookup table images of true dual-energy CT system after calibration scope optimization. (a) Carbon; (b) aluminum

Fig. 12. Pseudo dual-energy projection curve of copper

Fig. 13. Projection lookup table images of pseudo dual-energy CT system after calibration scope optimization. (a) Carbon; (b) aluminum