MultiImageAccessor2< Iter1, Acc1, Iter2, Acc2 > Class Template Reference

Access two images simultaneously. More...

#include <vigra/accessor.hxx>

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

Public Member Functions
	MultiImageAccessor2 (Iter1 i1, Acc1 a1, Iter2 i2, Acc2 a2)
template<class OFFSET >
value_type	operator() (OFFSET const &d) const
template<class OFFSET1 , class OFFSET2 >
value_type	operator() (OFFSET1 d1, OFFSET2 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. Sometimes, we need more information to calculate 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 algorithms. 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
	)

Construct from two image iterators and associated accessors.

Member Function Documentation

value_type operator()

(

OFFSET const &

d

)

const

read the current data item

value_type operator()	(	OFFSET1	d1,
		OFFSET2 const &	d2
	)		const

read the data item at an offset

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

• vigra/accessor.hxx