先对图像进行预处理，均衡化平滑滤波，二值化处理，在原图上画上网格。将图像边上一圈方格去除掉，使背景部分尽量最小化.标记联通区域，找到面积最大的区域就是人脸区域-First image preprocessing, equalization filtering, binarization, original paintings on the grid. The edge of the box around the image to get rid of, so as to minimize the background portion. Mark Unicom area, find the largest area of ​ ​ the region is the human face