距离变换，用chamfer方法，实现栅格距离变换、曼哈顿距离变换和棋盘距离变换-Distance transform method with a chamfer distance transform of Grid, Manhattan distance and the chessboard distance transform transformation

knn k近邻算法，可选择欧式距离或者曼哈顿距离-knn k nearest neighbor, Euclidean distance or Manhattan can choose the distance