bwgraph: Graph of connected pixels in images and volumes

Use to find the shortest path between 2 pixels or voxels.

bwgraph: Create a graph of connected pixels in 2D images or 3D volumes.

bwgraph can be used to find the shortest path between 2 pixels or voxels. See Examples.

Syntax

G = bwgraph( bw, Name=Value )

Inputs

Positional Argument	Description
bw	Binary image, given as a 2D or 3D, numeric or logical array. For numeric input, non-zero pixels are considered to be 1 (true).

Name-Value Argument	Description
Connectivity	Pixel connectivity, defining whether pixels are connected when they share either a face, edge, or corner. For a 2D bw, valid values are 4 (edge) and 8 (corner), and in 3D, 6 (face), 18 (edge) and 26 (corner). Default is the maximal connectivity, i.e., 8 or 26.
NodeWeights	Node weights, given for each element of bw. For example, the node weight could represent the distance between that pixel and the nearest non-zero pixel of bw, as calculated with bwdist. Edge weights for the graph are set as the mean node weight of the two connected pixels. Numeric array with the same size as bw.

Outputs

Argument	Description
G	graph object with nodes for all pixels of bw and edges between connected non-zero pixels. By default, edge weights are the Euclidean distance between the centers of connected pixels. The indices of the graph's nodes are equivalent to the linear indices of the pixels in bw. Therefore, use sub2ind and ind2sub to convert between pixel subscripts and node indices.

Examples

Please see examples.mlx or examples.pdf.

Compatibility, License and Citation

Created in 2022b. Compatible with MATLAB release 2019b and later. Compatible with all platforms.

Published under MIT License (see LICENSE.txt).

Please cite George Abrahams (https://github.com/WD40andTape/bwgraph, https://www.linkedin.com/in/georgeabrahams).