1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
## Copyright (C) 2024 David Legland
## All rights reserved.
##
## Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are met:
##
## 1 Redistributions of source code must retain the above copyright notice,
## this list of conditions and the following disclaimer.
## 2 Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in the
## documentation and/or other materials provided with the distribution.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS''
## AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
## IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
## ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
## ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
## SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
## CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
## OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
##
## The views and conclusions contained in the software and documentation are
## those of the authors and should not be interpreted as representing official
## policies, either expressed or implied, of the copyright holders.
function [nodes2, edges2] = grMergeNodeClusters(nodes, edges)
%GRMERGENODECLUSTERS Merge cluster of connected nodes in a graph.
%
% grMergeNodeClusters(nodes, edges)
% Detects groups of nodes that belongs to the same global node, and
% replace them by a unique node. Coordinates of reference node is given
% by the median coordinates of cluster nodes.
%
% This function is intended to be used as filter after a binary image
% skeletonization and vectorization.
%
%
% See also
% grMergeNodesMedian
%
% ------
% Author: David Legland
% E-mail: david.legland@inrae.fr
% Created: 2003-08-13
% Copyright 2003-2023 INRA - TPV URPOI - BIA IMASTE
%% Initialization
% intialize result
nodes2 = nodes;
edges2 = edges;
% compute degree of each node
degrees = grNodeDegree(1:size(nodes, 1), edges)';
% find index of multiple nodes
indMul = find(degrees > 2);
% indices of edges that link several multiple nodes
indEdges = sum(ismember(edges, indMul), 2) == 2;
% associate a label to each cluster
labels = grLabel(nodes, edges(indEdges, :));
clusterLabels = unique(labels(indMul));
%% Replace each cluster by median point
% iterate on clusters
for i = 1:length(clusterLabels)
% indices of nodes of the current cluster
inds = find(labels == clusterLabels(i));
% coordinates of new reference node
clusterNodes = nodes(inds, :);
medianNode = median(clusterNodes, 1);
% replace coordinates of reference node
refNode = min(inds);
nodes2(refNode, :) = medianNode;
% replace node indices in edge array
edges2(ismember(edges2, inds)) = refNode;
end
%% Clean up
% keep only relevant nodes
inds = unique(edges2(:));
nodes2 = nodes2(inds, :);
% relabeling of edges
for i = 1:length(inds)
edges2(edges2 == inds(i)) = i;
end
% remove double edges
edges2 = unique(sort(edges2, 2), 'rows');
% remove 'loops'
edges2(edges2(:,1) == edges2(:,2), :) = [];
|
