rag

RAG

class skimage.future.graph.RAG(label_image=None, connectivity=1, data=None, **attr) [source]

Bases: networkx.classes.graph.Graph

The Region Adjacency Graph (RAG) of an image, subclasses networx.Graph

Parameters:

label_image : array of int An initial segmentation, with each region labeled as a different integer. Every unique value in label_image will correspond to a node in the graph. connectivity : int in {1, ..., label_image.ndim}, optional The connectivity between pixels in label_image. For a 2D image, a connectivity of 1 corresponds to immediate neighbors up, down, left, and right, while a connectivity of 2 also includes diagonal neighbors. See scipy.ndimage.generate_binary_structure. data : networkx Graph specification, optional Initial or additional edges to pass to the NetworkX Graph constructor. See networkx.Graph. Valid edge specifications include edge list (list of tuples), NumPy arrays, and SciPy sparse matrices. **attr : keyword arguments, optional Additional attributes to add to the graph.

__init__(label_image=None, connectivity=1, data=None, **attr) [source]

add_edge(u, v, attr_dict=None, **attr) [source]

Add an edge between u and v while updating max node id.

See also

networkx.Graph.add_edge().

add_node(n, attr_dict=None, **attr) [source]

Add node n while updating the maximum node id.

See also

networkx.Graph.add_node().

copy() [source]

Copy the graph with its max node id.

See also

networkx.Graph.copy().

merge_nodes(src, dst, weight_func=, in_place=True, extra_arguments=[], extra_keywords={}) [source]

Merge node src and dst.

The new combined node is adjacent to all the neighbors of src and dst. weight_func is called to decide the weight of edges incident on the new node.

Parameters:

src, dst : int Nodes to be merged. weight_func : callable, optional Function to decide edge weight of edges incident on the new node. For each neighbor n for src and `dst, weight_func will be called as follows: weight_func(src, dst, n, *extra_arguments, **extra_keywords). src, dst and n are IDs of vertices in the RAG object which is in turn a subclass of networkx.Graph. in_place : bool, optional If set to True, the merged node has the id dst, else merged node has a new id which is returned. extra_arguments : sequence, optional The sequence of extra positional arguments passed to weight_func. extra_keywords : dictionary, optional The dict of keyword arguments passed to the weight_func.

Returns:

id : int The id of the new node.

Notes

If in_place is False the resulting node has a new id, rather than dst.

next_id() [source]

Returns the id for the new node to be inserted.

The current implementation returns one more than the maximum id.

Returns:	id : int The id of the new node to be inserted.