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details MultiImageAccessor2 Class Template Reference VIGRA

Access two images simultaneously. More...

#include "vigra/accessor.hxx"


Public Types

typedef pair< typename Acc1::value_type,
typename Acc2::value_type > 
value_type

Public Methods

 MultiImageAccessor2 (Iter1 i1, Acc1 a1, Iter2 i2, Acc2 a2)
template<class DIFFERENCE> value_type operator() (DIFFERENCE const &d) const
template<class DIFFERENCE1, class DIFFERENCE2> value_type operator() (DIFFERENCE1 d1, DIFFERENCE2 const &d2) const


Detailed Description


template<class Iter1, class Acc1, class Iter2, class Acc2>
class vigra::MultiImageAccessor2< Iter1, Acc1, Iter2, Acc2 >

Access two images simultaneously.

This accessor is used when two images need to be treated as one because an algorithm accepts only one image. For example, seededRegionGrowing() uses only one image two calculate the cost for aggregating each pixel into a region. Somtimes, we need more information to calcuate this cost, for example gray value and local gradient magnitude. These values can be stored in two images, which appear as only one when we pass a MultiImageAccessor2 to the lagorithms. Of course, the cost functor must accept a pair of values for this to work. Instead of an actual image iterator, we pass a CoordinateIterator which selects the right pixels form both images.

Usage:

#include "vigra/accessor.hxx"
Namespace: vigra

    using namespace vigra;

    FImage gray_values(w,h), gradient_magnitude(w,h);
    IImage seeds(w,h), labels(w,h);

    seededRegionGrowing(
        srcIterRange(CoordinateIterator(), CoordinateIterator(w,h),
           MultiImageAccessor2<FImage::iterator, FImage::Accessor,
                               FImage::iterator, FImage::Accessor>
                              (gray_values.upperLeft(), gray_values.accessor(),
                               gradient_magnitude.upperLeft(), gradient_magnitude.accessor())),
        srcImage(seeds),
        destImage(labels),
        SomeCostFunctor());


Member Typedef Documentation


typedef pair<typename Acc1::value_type, typename Acc2::value_type> value_type

 

The accessors value_type: construct a pair that contains the corresponding image values.


Constructor & Destructor Documentation


MultiImageAccessor2 Iter1    i1,
Acc1    a1,
Iter2    i2,
Acc2    a2
[inline]

 

Construct from two image iterators and associated accessors.


Member Function Documentation


value_type operator() DIFFERENCE1    d1,
DIFFERENCE2 const &    d2
const [inline]

 

read the data item at an offset


value_type operator() DIFFERENCE const &    d const [inline]

 

read the current data item


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

© Ullrich Köthe (koethe@informatik.uni-hamburg.de)
Cognitive Systems Group, University of Hamburg, Germany

html generated using doxygen and Python
VIGRA 1.3.2 (27 Jan 2005)