中文说明：经典的边缘检测sobel算子，只有简单的代码，仅供参考，没有研究价值，为了得到几分才上传得，大神情绕道，如果愿意指点不胜感激。
English Description：
The classic edge detection Sobel operator, only simple code, for reference only, no research value, in order to get a few points to upload, big look detour, if you are willing to point, thank you very much.