I. INTRODUCTION
Face recognition technology is the use of computer
analysis of face images, and extracted from the face images
effective identification information of technology.
Preprocessing in face recognition including: image rotation,
image mask, scale normalization, histogram normalization,
illumination compensation, etc. The purpose of
preprocessing is to improve the recognition rate, to a certain
extent, can improve the recognition speed to improve the rate
of face recognition. U-face concept was first proposed in the
image preprocessing. Kernel Principal Component Analysis
(KPCA) face recognition method is a classical based on the
statistical characteristics of face recognition methods; it is
generally believed that the method is better than Principal
Component Analysis (PCA) face recognition method.