程序功能：

1、对原始dicom病例进行中值滤波（滤波模板为3x3）

2、进行阈值分割及筛除步骤

3、导入肝掩膜凸壳，并对其腐蚀（腐蚀结构元素半径为10）

4、对2步骤中结果与肝掩膜做与运算-　Program features: 1　of the original cases were dicom median filter (filter template for 3x3)　2, threshold segmentation and screening Step 3　import liver mask convex hull, and its corrosion (corrosion of structural elements radius 10) 4 , the result of the second step and do a mask and liver operation