ITK  4.2.0
Insight Segmentation and Registration Toolkit
itkConnectedComponentAlgorithm.h
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18 #ifndef __itkConnectedComponentAlgorithm_h
19 #define __itkConnectedComponentAlgorithm_h
20 
21 #include "itkImage.h"
23 
24 namespace itk
25 {
26 template< class TIterator >
27 TIterator *
28 setConnectivity(TIterator *it, bool fullyConnected = false)
29 {
30  typename TIterator::OffsetType offset;
31  it->ClearActiveList();
32  if ( !fullyConnected )
33  {
34  // only activate the neighbors that are face connected
35  // to the current pixel. do not include the center pixel
36  offset.Fill(0);
37  for ( unsigned int d = 0; d < TIterator::Dimension; ++d )
38  {
39  offset[d] = -1;
40  it->ActivateOffset(offset);
41  offset[d] = 1;
42  it->ActivateOffset(offset);
43  offset[d] = 0;
44  }
45  }
46  else
47  {
48  // activate all neighbors that are face+edge+vertex
49  // connected to the current pixel. do not include the center pixel
50  unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
51  for ( unsigned int d = 0; d < centerIndex * 2 + 1; d++ )
52  {
53  offset = it->GetOffset(d);
54  it->ActivateOffset(offset);
55  }
56  offset.Fill(0);
57  it->DeactivateOffset(offset);
58  }
59  return it;
60 }
61 
62 template< class TIterator >
63 TIterator *
64 setConnectivityPrevious(TIterator *it, bool fullyConnected = false)
65 {
66  // activate the "previous" neighbours
67  typename TIterator::OffsetType offset;
68  it->ClearActiveList();
69  if ( !fullyConnected )
70  {
71  // only activate the neighbors that are face connected
72  // to the current pixel. do not include the center pixel
73  offset.Fill(0);
74  for ( unsigned int d = 0; d < TIterator::Dimension; ++d )
75  {
76  offset[d] = -1;
77  it->ActivateOffset(offset);
78  offset[d] = 0;
79  }
80  }
81  else
82  {
83  // activate all neighbors that are face+edge+vertex
84  // connected to the current pixel. do not include the center pixel
85  unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
86  for ( unsigned int d = 0; d < centerIndex; d++ )
87  {
88  offset = it->GetOffset(d);
89  it->ActivateOffset(offset);
90  }
91  offset.Fill(0);
92  it->DeactivateOffset(offset);
93  }
94  return it;
95 }
96 
97 template< class TIterator >
98 TIterator *
99 setConnectivityLater(TIterator *it, bool fullyConnected = false)
100 {
101  // activate the "later" neighbours
102  typename TIterator::OffsetType offset;
103  it->ClearActiveList();
104  if ( !fullyConnected )
105  {
106  // only activate the neighbors that are face connected
107  // to the current pixel. do not include the center pixel
108  offset.Fill(0);
109  for ( unsigned int d = 0; d < TIterator::Dimension; ++d )
110  {
111  offset[d] = 1;
112  it->ActivateOffset(offset);
113  offset[d] = 0;
114  }
115  }
116  else
117  {
118  // activate all neighbors that are face+edge+vertex
119  // connected to the current pixel. do not include the center pixel
120  unsigned int centerIndex = it->GetCenterNeighborhoodIndex();
121  for ( unsigned int d = centerIndex + 1; d < 2 * centerIndex + 1; d++ )
122  {
123  offset = it->GetOffset(d);
124  it->ActivateOffset(offset);
125  }
126  offset.Fill(0);
127  it->DeactivateOffset(offset);
128  }
129  return it;
130 }
131 }
132 
133 #endif
134