1 #ifndef __fpa__Image__SkeletonFilter__hxx__
2 #define __fpa__Image__SkeletonFilter__hxx__
4 #include <fpa/Base/Functors/Inverse.h>
5 #include <fpa/Image/Functors/SimpleNeighborhood.h>
6 #include <itkImageRegionIteratorWithIndex.h>
8 // -------------------------------------------------------------------------
9 #define fpa_Image_SkeletonFilter_OutputMacro( o_n, o_t ) \
10 template< class _TImage > \
11 typename fpa::Image::SkeletonFilter< _TImage >:: \
12 o_t* fpa::Image::SkeletonFilter< _TImage >:: \
16 dynamic_cast< o_t* >( \
17 this->itk::ProcessObject::GetOutput( this->m_##o_n##Idx ) \
22 fpa_Image_SkeletonFilter_OutputMacro( Skeleton, TSkeleton );
23 fpa_Image_SkeletonFilter_OutputMacro( Marks, TMarks );
25 // -------------------------------------------------------------------------
26 template< class _TImage >
27 fpa::Image::SkeletonFilter< _TImage >::
31 typedef typename _TImage::PixelType _TPixel;
32 typedef typename _TImage::Superclass _TImageBase;
33 typedef fpa::Image::Functors::SimpleNeighborhood< _TImageBase > _TNeighFunc;
34 typedef fpa::Base::Functors::Inverse< _TPixel, _TPixel > _TInvFunc;
36 unsigned int nOutputs = this->GetNumberOfRequiredOutputs( );
37 this->SetNumberOfRequiredOutputs( nOutputs + 2 );
38 this->m_SkeletonIdx = nOutputs;
39 this->m_MarksIdx = nOutputs + 1;
41 typename TSkeleton::Pointer skeleton = TSkeleton::New( );
42 typename TMarks::Pointer marks = TMarks::New( );
43 this->SetNthOutput( this->m_SkeletonIdx, skeleton.GetPointer( ) );
44 this->SetNthOutput( this->m_MarksIdx, marks.GetPointer( ) );
46 typename _TNeighFunc::Pointer nfunc = _TNeighFunc::New( );
48 this->SetNeighborhoodFunction( nfunc );
50 typename _TInvFunc::Pointer ifunc = _TInvFunc::New( );
51 this->SetCostConversionFunction( ifunc );
54 // -------------------------------------------------------------------------
55 template< class _TImage >
56 fpa::Image::SkeletonFilter< _TImage >::
61 // -------------------------------------------------------------------------
62 template< class _TImage >
63 void fpa::Image::SkeletonFilter< _TImage >::
64 _BeforeGenerateData( )
66 this->Superclass::_BeforeGenerateData( );
67 this->m_SkeletonQueue.clear( );
70 // -------------------------------------------------------------------------
71 template< class _TImage >
72 void fpa::Image::SkeletonFilter< _TImage >::
73 _UpdateResult( const _TQueueNode& n )
75 typedef typename _TSkeletonQueue::value_type _TSkeletonQueueValue;
77 this->Superclass::_UpdateResult( n );
78 double d = double( this->GetInput( )->GetPixel( n.Vertex ) );
79 if( d >= double( 0 ) )
81 // Update skeleton candidates
83 double v = double( n.Result ) / ( d * d );
84 this->m_SkeletonQueue.insert( _TSkeletonQueueValue( v, n.Vertex ) );
89 // -------------------------------------------------------------------------
90 template< class _TImage >
91 void fpa::Image::SkeletonFilter< _TImage >::
94 this->Superclass::_AfterGenerateData( );
96 std::vector< TIndex > end_points;
97 this->_EndPoints( end_points );
98 this->_Skeleton( end_points );
101 // -------------------------------------------------------------------------
102 template< class _TImage >
103 void fpa::Image::SkeletonFilter< _TImage >::
104 _EndPoints( std::vector< TIndex >& end_points )
106 typedef itk::ImageRegionIteratorWithIndex< TMarks > _TMarksIt;
108 static const double _eps = std::sqrt( double( Self::Dimension + 1 ) );
109 auto input = this->GetInput( );
110 auto mst = this->GetMinimumSpanningTree( );
111 auto marks = this->GetMarks( );
114 marks->SetLargestPossibleRegion( input->GetLargestPossibleRegion( ) );
115 marks->SetRequestedRegion( input->GetRequestedRegion( ) );
116 marks->SetBufferedRegion( input->GetBufferedRegion( ) );
117 marks->SetSpacing( input->GetSpacing( ) );
118 marks->SetOrigin( input->GetOrigin( ) );
119 marks->SetDirection( input->GetDirection( ) );
121 marks->FillBuffer( 0 );
122 auto spac = marks->GetSpacing( );
124 // BFS from maximum queue
125 auto region = input->GetRequestedRegion( );
126 while( this->m_SkeletonQueue.size( ) > 0 )
129 auto nIt = this->m_SkeletonQueue.begin( );
131 this->m_SkeletonQueue.erase( nIt );
133 // Mark it and update end-points
134 unsigned char m = marks->GetPixel( n.second );
137 marks->SetPixel( n.second, 1 );
138 end_points.push_back( n.second );
141 TIndex it = n.second;
142 TIndex p = mst->GetParent( it );
145 // TODO: tags->SetPixel( it, tags->GetPixel( it ) + 1 );
147 p = mst->GetParent( it );
150 // TODO: tags->SetPixel( it, tags->GetPixel( it ) + 1 );
152 /* TODO: use mst directly rather than computing paths
153 typename TMST::TPath::Pointer path;
154 mst->GetPath( path, n.second );
155 for( unsigned long i = 0; i < path->GetSize( ); ++i )
157 TIndex idx = path->GetVertex( i );
158 typename _TImage::PointType cnt;
159 input->TransformIndexToPhysicalPoint( idx, cnt );
160 double r = double( input->GetPixel( idx ) ) * _eps;
163 for( unsigned int d = 0; d < Self::Dimension; ++d )
165 long off = long( std::ceil( r / double( spac[ d ] ) ) );
168 i0[ d ] = idx[ d ] - off;
169 i1[ d ] = idx[ d ] + off;
171 if( i0[ d ] < region.GetIndex( )[ d ] )
172 i0[ d ] = region.GetIndex( )[ d ];
174 if( i1[ d ] >= region.GetIndex( )[ d ] + region.GetSize( )[ d ] )
175 i1[ d ] = region.GetIndex( )[ d ] + region.GetSize( )[ d ] - 1;
179 typename _TImage::SizeType size;
180 for( unsigned int d = 0; d < Self::Dimension; ++d )
181 size[ d ] = i1[ d ] - i0[ d ] + 1;
183 typename _TImage::RegionType neighRegion;
184 neighRegion.SetIndex( i0 );
185 neighRegion.SetSize( size );
187 _TMarksIt mIt( marks, neighRegion );
188 for( mIt.GoToBegin( ); !mIt.IsAtEnd( ); ++mIt )
190 TIndex w = mIt.GetIndex( );
191 typename _TImage::PointType p;
192 marks->TransformIndexToPhysicalPoint( w, p );
203 // -------------------------------------------------------------------------
204 template< class _TImage >
205 void fpa::Image::SkeletonFilter< _TImage >::
206 _Skeleton( const std::vector< TIndex >& end_points )
208 typedef itk::Image< unsigned long, Self::Dimension > _TTagsImage;
209 typedef typename TMST::TPath _TPath;
211 auto mst = this->GetMinimumSpanningTree( );
212 auto skeleton = this->GetSkeleton( );
215 typename _TTagsImage::Pointer tags = _TTagsImage::New( );
216 tags->SetLargestPossibleRegion( mst->GetLargestPossibleRegion( ) );
217 tags->SetRequestedRegion( mst->GetRequestedRegion( ) );
218 tags->SetBufferedRegion( mst->GetBufferedRegion( ) );
220 tags->FillBuffer( 0 );
221 for( auto eIt = end_points.begin( ); eIt != end_points.end( ); ++eIt )
224 TIndex p = mst->GetParent( it );
227 tags->SetPixel( it, tags->GetPixel( it ) + 1 );
229 p = mst->GetParent( it );
232 tags->SetPixel( it, tags->GetPixel( it ) + 1 );
236 // Build paths (branches)
237 for( auto eIt = end_points.begin( ); eIt != end_points.end( ); ++eIt )
240 TIndex p = mst->GetParent( it );
242 typename _TPath::Pointer path = _TPath::New( );
243 path->SetReferenceImage( mst );
246 if( tags->GetPixel( sIdx ) != tags->GetPixel( it ) )
248 // Ok, a new branch has been added
249 path->AddVertex( it );
250 skeleton->AddBranch( path );
252 // Update a new starting index
253 path = _TPath::New( );
254 path->SetReferenceImage( mst );
258 path->AddVertex( it );
260 p = mst->GetParent( it );
264 // Finally, add last branch
265 path->AddVertex( it );
266 skeleton->AddBranch( path );
271 #endif // __fpa__Image__SkeletonFilter__hxx__