这是一个简单的使用snake模型进行图像分割的源代码，可以用来学习，事先需要确定一个初始化的轮廓，最好和真实的轮廓相距不是太大(his is a simple use of the snake model for the image segmentation source code, can be used for learning, prior need to determine an initial profile, the best and the actual contour is not too large)