DGtal::detail::NormalVectorFromDCA Struct Reference

#include <DGtal/geometry/curves/estimation/SegmentComputerEstimators.h>

Public Types
typedef PointVector< 2, double >	Value

Public Member Functions
template<typename DCA >
Value	operator() (const typename DCA::ConstIterator &it, const DCA &aDCA) const

Detailed Description

Description of class 'NormalVectorFromDCA'

Aim: estimates the normal at a given position from a geometricDCA.

Definition at line 829 of file SegmentComputerEstimators.h.

Member Typedef Documentation

Value

typedef PointVector<2,double> DGtal::detail::NormalVectorFromDCA::Value

Definition at line 832 of file SegmentComputerEstimators.h.

Member Function Documentation

operator()()

template<typename DCA >

Value DGtal::detail::NormalVectorFromDCA::operator() ( const typename DCA::ConstIterator &  it, const DCA &  aDCA  ) const

inline

Operator()

Returns

normal at it

Parameters

it	position where the estimation has to be done
aDCA	an instance of segment computer devoted to the DCA recognition.

Template Parameters

DCA	a model of segment computer devoted to the DCA recognition, basically geometricDCA.

Definition at line 849 of file SegmentComputerEstimators.h.

      {
        typedef typename DCA::Pair Pair; 
        typedef typename DCA::Point Point;
        typedef typename Point::Coordinate Coordinate; 
        
        if ( !aDCA.isStraight() )
        {
          //separating circle center
          double c0, c1, r; 
          aDCA.getSeparatingCircle().getParameters(c0, c1, r);
          //point
          Pair pair = *it; 
          Point i = pair.first; 
          Point o = pair.second;
          double m0 = NumberTraits<Coordinate>::castToDouble(i[0]+o[0]) / 2.0; 
          double m1 = NumberTraits<Coordinate>::castToDouble(i[1]+o[1]) / 2.0;
          //normal vector 
          double v0 = m0 - c0; 
          double v1 = m1 - c1; 
          //norm
          double n = std::sqrt(v0*v0 + v1*v1); 
          return Value( v0/n, v1/n );
        }
            else
        {
          //separating straight line and normal vector
          double a, b, c; 
          aDCA.getStabbingLineComputerPtr()->getParameters(a, b, c);
          //norm
          double n = std::sqrt(a*a + b*b); 
          return Value( a/n, b/n ); 
        }
      }

References DGtal::NumberTraitsImpl< std::decay< T >::type >::castToDouble().

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The documentation for this struct was generated from the following file:

• SegmentComputerEstimators.h