Optimization in Graphics
Add preprocessing based on the technique developed by Tan and Triggs:
Tan, X., and Triggs, B. "Enhanced local texture feature sets for face recognition under difficult lighting conditions.". IEEE
Transactions on Image Processing 19 (2010), 1635–650.
I noted an unsignificant change in recognition performance on the ORL database,
the real value will need to be evaluated with real-world pictures.