该代码实现了基于水平集的图像边缘检测，此改进模型不仅适用于血管壁的内膜，也适用于外膜的提取。实验证明，此改进的水平集模型具备有效性和可实现性。-This improved model not only applies to the intravascular blood vessel, but also to extract the outer membrane. Experiments show that the improved level set model proposed in thi