导入人脸图像，根据Canny算法查找第一个边缘点，搜索邻域边缘点以最后一个边缘点作为新起点，进行下一轮搜索，初始化Hough矩阵确定瞳孔边缘界限计算瞳孔面积，定位瞳孔圆心坐标-Import facial image, according to Canny algorithm to find the first edge point, the search neighborhood edge point to the last point of the edge of a new starting