contours.py 文件源码

def skel_to_graph(skel):
    """
    Transform skeleton into its branches and nodes, by counting the number
    of neighbors of each pixel in the skeleton
    """
    convolve_skel = 3**skel.ndim * ndimage.uniform_filter(skel.astype(np.float)) # 3x3 square mean
    neighbors = np.copy(skel.astype(np.uint8))
    skel = skel.astype(np.bool)
    neighbors[skel] = convolve_skel[skel] - 1
    edges = morphology.label(np.logical_or(neighbors == 2, neighbors ==1),
                            background=0)
    nodes = morphology.label(np.logical_and(np.not_equal(neighbors, 2),
                                            neighbors > 0), background=0)
    length_edges = np.bincount(edges.ravel())
    return nodes, edges, length_edges