vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR > Class Template Reference

interpolation at non-integer positions. More...

#include <Interpolators.h>

Public Types
typedef VALUETYPE	value_type
	the iterators' pixel type More...

Public Member Functions
	InterpolatingAccessor (ACCESSOR a, INTERPOLATOR inter)
	init from given accessor More...
template<class ITERATOR >
value_type	operator() (ITERATOR const &i, float x, float y) const
	Interpolate the data item at a non-integer position x, y. More...
template<class ITERATOR , class ALPHAITERATOR , class ALPHAACCESSOR >
bool	operator() (ITERATOR const &i, std::pair< ALPHAITERATOR, ALPHAACCESSOR > const &alpha, float x, float y, value_type &result) const
	Interpolate the data item at a non-integer position x, y. More...

Private Attributes
ACCESSOR	a_
INTERPOLATOR	inter_x
INTERPOLATOR	inter_y

Detailed Description

template<class ACCESSOR, class VALUETYPE, class INTERPOLATOR>
class vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >

interpolation at non-integer positions.

This accessor allows an image be accessed at arbitrary non-integer coordinates and performs an interpolation to obtain a pixel value. It uses the given ACCESSOR (which is usually the accessor originally associated with the iterator) to access data.

The interpolation algorithm is given as a template parameter, INTERPOLATOR. See the interp_bilin interp_cubic, interp_spline16, interp_spline36, interp_spline64 and interp_sinc for possible interpolators

Namespace: vigra

Usage

// used variables:
// iterator  : pointing to upperLeft
// accessor  : accessor to the source image
// dest      : value, interpolated at sx, m_sIter (relative to iterator)

interp_cubic iterp;
InterpolatingAccessor<SrcAccessor,
    typename SrcAccessor::value_type,Interpolator> interpol(accessor, interp);

...
double sx = 102.1;
double m_sIter = 58,81;
dest = interpol(iterator, sx, m_sIter);

<b> Required Interface:</b>

\code
ITERATOR iter;
ACCESSOR a;
VALUETYPE destvalue;
INTERPOLATOR interp;
const int interp.size;
float s;
int x, y;

void interp::calc_coeff(double x);
destvalue = s * a(iter, x, y) + s * a(iter, x, y);

Definition at line 857 of file Interpolators.h.

Member Typedef Documentation

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

typedef VALUETYPE vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::value_type

the iterators' pixel type

Definition at line 862 of file Interpolators.h.

Constructor & Destructor Documentation

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::InterpolatingAccessor ( ACCESSOR  a, INTERPOLATOR  inter  )

inline

init from given accessor

Definition at line 866 of file Interpolators.h.

Member Function Documentation

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

template<class ITERATOR >

value_type vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::operator() ( ITERATOR const &  i, float  x, float  y  ) const

inline

Interpolate the data item at a non-integer position x, y.

be careful, no bounds checking is done here. take INTERPOLATOR::size into accout before iterating over the picture.

the used image pixels are [i-(n/2 -1) .. i+n/2], where n is the size of the interpolator

Parameters

i	base iterator
x	x position, relative to i and alpha.first
y	y position, relative to i and alpha.first

Returns

interpolation result

Definition at line 887 of file Interpolators.h.

References vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::a_, vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_x, and vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_y.

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

template<class ITERATOR , class ALPHAITERATOR , class ALPHAACCESSOR >

bool vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::operator() ( ITERATOR const &  i, std::pair< ALPHAITERATOR, ALPHAACCESSOR > const &  alpha, float  x, float  y, value_type &  result  ) const

inline

Interpolate the data item at a non-integer position x, y.

It checks if the interpolation would access a pixel with alpha = 0 and returns false in that case.

be careful, no bounds checking is done here. take INTERPOLATOR::size into accout before iterating over the picture.

the used image pixels are [i-(n/2 -1) .. i+n/2], where n is the size of the interpolator

Parameters

i	base iterator
alpha	alpha image
x	x position, relative to i and alpha.first
y	y position, relative to i and alpha.first
result	the interpolation result

Returns

true if interpolation ok, false if one or more pixels were masked out

Definition at line 937 of file Interpolators.h.

References vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::a_, vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_x, and vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_y.

Member Data Documentation

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

ACCESSOR vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::a_

private

Definition at line 975 of file Interpolators.h.

Referenced by vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::operator()().

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

INTERPOLATOR vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_x

private

Definition at line 976 of file Interpolators.h.

Referenced by vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::operator()().

template<class ACCESSOR , class VALUETYPE , class INTERPOLATOR >

INTERPOLATOR vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::inter_y

private

Definition at line 976 of file Interpolators.h.

Referenced by vigra_ext::InterpolatingAccessor< ACCESSOR, VALUETYPE, INTERPOLATOR >::operator()().

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

• hugin_base/vigra_ext/Interpolators.h