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