说明：  直方图阈值法 自动阈值法：Otsu法 膨胀操作 腐蚀操作 开启和闭合操作 开启和闭合组合操作 形态学边界提取
(Histogram Threshold automatic threshold: Otsu method dilation etching operation opening and closing operation of the opening and closing operation of a combination of morphological boundary extraction)