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00017 #ifndef __itkPathFunctions_h
00018 #define __itkPathFunctions_h
00019
00020
00021 #include "itkPath.h"
00022 #include "itkChainCodePath.h"
00023 #include "itkFourierSeriesPath.h"
00024 #include "itkOffset.h"
00025 #include <math.h>
00026
00027 namespace itk
00028 {
00033 template <class TChainCodePath, class TPathInput>
00034 void MakeChainCodeTracePath( TChainCodePath & chainPath,
00035 const TPathInput & inPath,
00036 bool restrictMovement = false )
00037 {
00038 typedef typename TChainCodePath::OffsetType OffsetType;
00039 typedef typename TChainCodePath::InputType ChainInputType;
00040 typedef typename TChainCodePath::OutputType ChainOutputType;
00041 typedef typename TPathInput::InputType InPathInputType;
00042 typedef typename TPathInput::OutputType InPathOutputType;
00043
00044 OffsetType offset, tempOffset, zeroOffset;
00045 InPathInputType inPathInput;
00046 int dimension = OffsetType::GetOffsetDimension();
00047
00048 zeroOffset.Fill(0);
00049
00050 chainPath.Clear();
00051 inPathInput = inPath.StartOfInput();
00052 chainPath.SetStart( inPath.EvaluateToIndex( inPathInput ) );
00053
00054 for(ChainInputType chainInput=0;;)
00055 {
00056 offset = inPath.IncrementInput(inPathInput);
00057 if( zeroOffset == offset ) { break; }
00058
00059 if( ! restrictMovement )
00060 {
00061 chainPath.InsertStep( chainInput++, offset );
00062 }
00063 else
00064 {
00065 for( int d=0; d<dimension; d++ )
00066 {
00067 tempOffset.Fill(0);
00068 tempOffset[d] = offset[d];
00069 chainPath.InsertStep( chainInput++, tempOffset );
00070 }
00071 }
00072 }
00073 }
00074
00081 template <class TFourierSeriesPath, class TChainCodePath>
00082 void MakeFourierSeriesPathTraceChainCode( TFourierSeriesPath & FSPath,
00083 const TChainCodePath & chainPath,
00084 unsigned int numHarmonics = 8 )
00085 {
00086 typedef typename TFourierSeriesPath::IndexType IndexType;
00087 typedef typename TFourierSeriesPath::OffsetType OffsetType;
00088 typedef typename TFourierSeriesPath::VectorType VectorType;
00090
00091 typedef typename TFourierSeriesPath::InputType FSInputType;
00092 typedef typename TFourierSeriesPath::OutputType FSOutputType;
00093 typedef typename TChainCodePath::InputType ChainInputType;
00094 typedef typename TChainCodePath::OutputType ChainOutputType;
00095
00096 IndexType index;
00097 VectorType indexVector;
00098 VectorType cosCoefficient;
00099 VectorType sinCoefficient;
00100 FSInputType theta;
00101 int dimension = OffsetType::GetOffsetDimension();
00102 unsigned numSteps = chainPath.NumberOfSteps();
00103
00104 const double PI = 4.0 * vcl_atan( 1.0 );
00105
00106 FSPath.Clear();
00107
00108
00109 if( numHarmonics <= 1 )
00110 numHarmonics = 2;
00111 else if( numHarmonics*2 > numSteps )
00112 numHarmonics = numSteps / 2;
00113
00114 for( unsigned n=0; n<numHarmonics; n++ )
00115 {
00116 index = chainPath.GetStart();
00117 cosCoefficient.Fill(0.0);
00118 sinCoefficient.Fill(0.0);
00119
00120 for( ChainInputType step=0; step<numSteps; step++ )
00121 {
00122 index += chainPath.Evaluate( step );
00123 theta = 2 * n * PI * ( double(step+1)) / numSteps;
00124
00125
00126 for( int d=0; d<dimension; d++ )
00127 {
00128 indexVector[d] = index[d];
00129 }
00130 cosCoefficient += indexVector * (vcl_cos(theta)/numSteps);
00131 sinCoefficient += indexVector * (vcl_sin(theta)/numSteps);
00132 }
00133
00134 FSPath.AddHarmonic( cosCoefficient, sinCoefficient );
00135 }
00136 }
00137
00138 }
00139
00140 #endif
00141