说明：  这是一篇被SCI所收录了的基于Sobel细化算法的螺纹边缘检测的博士论文,对于工程设计和学习都具有极高的参考学习价值
(This is a SCI were included by the thinning algorithm based on Sobel edge detection thread doctoral thesis, for engineering design and learning have a very high value of the reference study)