实现多光谱图像的物质分类和显示，并进行面积统计。可以设置类数和采样数，采样时，用鼠标选取采样点，每类采样点选完，需要输入类名-This program can realize the classification and demonstration of multispectral images,and the area statistics of the class. In the program, you can set the number of class and sampling fr