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 this thesis is effective and achievability.