Rapid algorithm of template matching for face detection
适于人脸检测的模板匹配快速算法

In order to improve the speed of template matching in face detection, based on integral image, a square integral image was proposed and used to realize a rapid algorithm for calculating grayscale average and variance of image windows, and the calculating speed was independent on the windows size. With this rapid algorithm and transformation of some formulas, such as approximate formulas for computing grayscale distribution normalization, formulas for computing the correlation coefficient and average deviation, and leaving out some needless processes such as copying windows and conversion of windows grayscale value, the template matching was sped up greatly. Experiment results of face detection demonstrate the efficiency of this algorithm.