本程序是基于最大类间交叉熵的图象分割，它是从目标和背景的类间差异性出发, 搜索使分割后的类间差异最大的阈值。-This procedure is based on the maximum between-class cross-entropy image segmentation, it is from the target and background of the between-class differences, the search so that after the partitio