Fig. 1. Five basic Tetrominoes

Fig. 2. Flow chart of our method

Fig. 3. Result processed by our method. (a) Image processed by our method; (b) energy characteristic surface

Fig. 4. Energy difference surfaces under different conditions. (a) Image1 of the same person; (b) image2 of the same person (c) image of the different person; (d) matching energy difference surface; (e) mismatching energy difference surface

Fig. 5. Example of HKPU-FKP database ROI. (a) Original database; (b) noise database

Fig. 6. Histogram equalization contrast. (a) Image before equalization; (b) histogram before equalization; (c) image after equalization; (d) histogram after equalization

Fig. 7. Matching curve and ROC (HKPU-FKP and noise database). (a) Matching curve;(b) ROC

Fig. 8. Example of IIT Delhi-FK database. (a) Original database; (b) noise database

Fig. 9. Matching curve and ROC (IIT Delhi-FK and noise database). (a) Matching curve; (b) ROC

Fig. 10. Example of HKPU-CFK ROI database. (a) Original database; (b) noise database

Fig. 11. Matching curve and ROC (HKPU-CFK and noise database). (a) Matching curve; (b) ROC

Fig. 12. Correct recognition rate and matching time. (a) Correct recognition rate; (b) matching time