通过反复从对象中移除边缘像素，直到它们被减少到单像素宽的骨架，二值图像从而被细化得到根中轴(Smucker et al., 1987 Tanaka et al., 1995)。建立在NHI图像上的骨架化命令是用于此过程（见于Fig. 7(ii)）和计算骨架像素的数量。-The binary image was thinned to get the medial axis of roots by repeatedly removing edge pixels from the objects until they were reduced to single-pixel- wide skeletons (Smucker et al., 1987　Tanaka et al., 1995). The ‘Skeletonize’ command built into NIH Image was used for this process (Fig. 7(ii)) and the number of skeleton pixels was counted.