MIRA
CRSplineInterpolator.h
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38 
47 #ifndef _MIRA_CRSPLINEINTERPOLATOR_H_
48 #define _MIRA_CRSPLINEINTERPOLATOR_H_
49 
50 #include <math/IntervalFilter.h>
51 
52 namespace mira {
53 
55 
64 {
65 public:
66  bool canExtrapolate() const { return true; }
67  int samples() const { return 4; }
68  int samplesBefore() const { return 2; }
69  int samplesAfter() const { return 2; }
70 
71  template <typename Tx, typename Ty, typename ContainerTx, typename ContainerTy>
72  Ty apply(const ContainerTx& x, const ContainerTy& y, const Tx& xx)
73  {
74  assert(x.size()==y.size());
75  assert(x.size()==4);
76 
77  const int k = 1; // this is fixed since we assume that we get exactly 4 values
78 
79  Ty mk = (y[k+1]-y[k-1])/(x[k+1]-x[k-1]);
80  Ty mkp1 = (y[k+2]-y[k])/(x[k+2]-x[k]);
81 
82  Tx scale = (x[k+1]-x[k]);
83 
84  Tx t = (xx-x[k])/scale;
85 
86  Tx t2 = t*t;
87  Tx t3 = t2*t;
88 
89  // the hermite basis functions:
90  Tx h00 = 2*t3-3*t2+1;
91  Tx h10 = -h00+1;
92  Tx h01 = t3-2*t2+t;
93  Tx h11 = t3-t2;
94 
95  return h00*y[k] + h10*y[k+1] + h01*scale*mk + h11*scale*mkp1;
96  }
97 };
98 
100 
101 } // namespace
102 
103 #endif /* _MIRA_CRSPLINEINTERPOLATOR_H_ */
Ty apply(const ContainerTx &x, const ContainerTy &y, const Tx &xx)
Definition: CRSplineInterpolator.h:72
specialize cv::DataType for our ImgPixel and inherit from cv::DataType<Vec>
Definition: IOService.h:67
int samples() const
Definition: CRSplineInterpolator.h:67
bool canExtrapolate() const
Definition: CRSplineInterpolator.h:66
1D cubic Hermite spline interpolator.
Definition: CRSplineInterpolator.h:63
int samplesBefore() const
Definition: CRSplineInterpolator.h:68
IntervalFilter base class/concept.
Concept and base class for all Interpolators and Filters.
Definition: IntervalFilter.h:61
int samplesAfter() const
Definition: CRSplineInterpolator.h:69