用于图形的细化处理，vc6.0平台编译通过，注意，本程序的细化算法要应用于含线条的黑白二值图像才可以看出细化效果。-Thinning treatment for graphics, vc6.0 platform compiler passed, note that this procedure should be applied to the thinning algorithm with black-and-white line binary image thinning effect can