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/*========================================================================= |
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Program: Insight Segmentation & Registration Toolkit |
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Module: $RCSfile: itkChainCodePath2D.h.html,v $ |
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Language: C++ |
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Date: $Date: 2006/01/17 19:15:33 $ |
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Version: $Revision: 1.4 $ |
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Copyright (c) Insight Software Consortium. All rights reserved. |
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See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details. |
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This software is distributed WITHOUT ANY WARRANTY; without even |
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the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
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PURPOSE. See the above copyright notices for more information. |
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=========================================================================*/ |
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DEF |
#ifndef _itkChainCodePath2D_h |
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DEF |
#define _itkChainCodePath2D_h |
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#include "itkChainCodePath.h" |
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#include "itkObjectFactory.h" |
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#include "itkIndex.h" |
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#include "itkOffset.h" |
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#include <vector> |
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#include <string> |
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namespace itk |
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{ |
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/** \class ChainCodePath2D |
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* \brief Represent a 2D path as a sequence of connected image index offsets |
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* |
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* This class is intended to represent sequences of connected indices in a 2D |
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* image plane. It does so by storing the offset of each index from its immediately |
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* preceeding, connected, index using a standard Freeman code (1=up, 2=up to the right, and so on proceeding clockwise to 8=up to the left). The only image index stored directly is that |
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* of the first index. ChainCodePath2D maps a 1D integer input (step number) to |
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* a 2D interger output (either an offset or an image index, depending on |
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* whether Evaluate or EvaluateToIndex is called). |
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* |
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* \sa ChainCodePath |
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* \sa ParametricPath |
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* \sa Path |
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* \sa Index |
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* |
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* \ingroup PathObjects |
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*/ |
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class ITKCommon_EXPORT ChainCodePath2D : public |
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ChainCodePath<2> |
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{ |
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public: |
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/** Dimension underlying input image. */ |
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itkStaticConstMacro(Dimension, unsigned int, 2); |
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/** Standard class typedefs. */ |
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typedef ChainCodePath2D Self; |
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typedef ChainCodePath<2> Superclass; |
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typedef SmartPointer<Self> Pointer; |
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TDA |
typedef SmartPointer<const Self> ConstPointer; |
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/** Run-time type information (and related methods). */ |
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itkTypeMacro(ChainCodePath2D, ChainCodePath); |
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/** OutputType typedef support. */ |
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typedef Superclass::OutputType OutputType; |
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typedef Superclass::InputType InputType; |
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/** The output type of this function is an Index */ |
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typedef OutputType OffsetType; |
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typedef Index<2> IndexType; |
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/** ChainCodeType is a usless relic of the parent class */ |
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typedef std::vector<OffsetType> ChainCodeType; |
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/** ChainCodePath2D stores its data as a Freeman-encoded chain code */ |
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typedef std::vector<int> ChainCode2DType; |
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// Functions inherited from Path |
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/** Evaluate the chaincode for the offset at the specified path-position. */ |
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virtual OutputType Evaluate( const InputType & input ) const; |
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/** Like Evaluate(), but returns the index at the specified path-position. */ |
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virtual IndexType EvaluateToIndex( const InputType & input ) const; |
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/** Increment the input variable passed by reference and return the offset |
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* stored at the previous path-position. If the chaincode is unable to be |
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* incremented, input is not changed and an offset of zero is returned, which |
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* may be used to check for the end of the chain code. */ |
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virtual OffsetType IncrementInput(InputType & input) const; |
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EML |
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// Functions specific to ChainCodePath and its descendents |
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/** New() method for dynamic construction */ |
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itkNewMacro( Self ); |
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/** How many steps in the chaincode? */ |
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inline unsigned int NumberOfSteps() const { return m_Chain2D.size(); } |
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/** Insert a new step into the chaincode at a specified position */ |
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inline void InsertStep( InputType position, int encodedStep ) |
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**{ |
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m_Chain2D.insert( m_Chain2D.begin()+position, encodedStep ); |
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this->Modified(); |
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**} |
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inline void InsertStep( InputType position, OffsetType step ) |
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**{ |
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m_Chain2D.insert( m_Chain2D.begin()+position, EncodeOffset(step) ); |
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this->Modified(); |
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**} |
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/** Change the direction of a step in the chaincode */ |
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inline void ChangeStep( InputType position, int encodedStep ) |
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**{ |
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m_Chain2D[position]=encodedStep; |
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this->Modified(); |
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**} |
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inline void ChangeStep( InputType position, OffsetType step ) |
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**{ |
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m_Chain2D[position]=EncodeOffset(step); |
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this->Modified(); |
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**} |
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/** Remove all steps from the chain code */ |
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virtual inline void Clear() |
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{ |
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m_Chain2D.clear(); |
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this->Modified(); |
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} |
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std::string GetChainCodeAsString(void) const; |
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EML |
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protected: |
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ChainCodePath2D(); |
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~ChainCodePath2D(); |
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void PrintSelf(std::ostream& os, Indent indent) const; |
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/** Encode and Decode between an offset and a Freeman code */ |
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inline int EncodeOffset( OffsetType step ) const |
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{ |
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return m_FreemanCode[ step[0] + 1 ][ step[1] + 1 ]; |
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} |
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inline OffsetType DecodeOffset( int encodedStep ) const |
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{ |
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return m_ReverseFreemanCode[ encodedStep ]; |
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} |
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EML |
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private: |
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ChainCodePath2D(const Self&); //purposely not implemented |
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void operator=(const Self&); //purposely not implemented |
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ChainCode2DType m_Chain2D; // the Freeman-encoded chain code |
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// FreemanCode[][] implements a lookup table for converting offsets to a |
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// Freeman code. Within each dimension, the only allowable offset values are |
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// { -1, 0, 1 }. The y-axis is assumed to point up. It is initialized in the |
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// constructor. Use it as follows: |
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// |
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// encodedValue = m_FreemanCode[ x offset + 1 ][ y offset + 1 ] |
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// |
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int m_FreemanCode[3][3]; |
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// m_ReverseFreemanCode[ encodedValue ] implements a lookup table for the |
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// inverse of m_FreemanCode[][]. It is initialized in the constructor. |
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OffsetType m_ReverseFreemanCode[9]; |
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}; |
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} // namespace itk |
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#endif |
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