VectorComponentValueAccessor< VECTORTYPE > Class Template Reference

Accessor for one component of a vector. More...

#include <vigra/accessor.hxx>

Public Types
typedef VECTORTYPE::value_type	value_type

Public Member Functions
template<class ITERATOR >
value_type	operator() (ITERATOR const &i) const
template<class ITERATOR , class OFFSET >
value_type	operator() (ITERATOR const &i, OFFSET const &diff) const
template<class V , class ITERATOR >
void	set (V value, ITERATOR const &i) const
template<class V , class ITERATOR , class OFFSET >
void	set (V value, ITERATOR const &i, OFFSET const &diff) const
void	setIndex (int i)
	VectorComponentValueAccessor (int index)

Detailed Description

template<class VECTORTYPE>
class vigra::VectorComponentValueAccessor< VECTORTYPE >

Accessor for one component of a vector.

This accessor allows to select a single component (a single 'band') of a vector valued pixel type. The pixel type must support operator[]. The index of the component to be selected is passed in the constructor. The accessor returns its items by value. If you want to pass/return items by reference, use VectorComponentAccessor. If a floating point number is assigned by means of an accessor with integral value_type, the value is rounded and clipped as appropriate.

Usage:

vigra::BRGBImage image(w,h);

// init red channel with 255
initImage(destImageRange(image,
                         VectorComponentValueAccessor<vigra::BRGBImage::value_type>(0)),
          255);

#include <vigra/accessor.hxx>
Namespace: vigra

Member Typedef Documentation

typedef VECTORTYPE::value_type value_type

the value_type

Constructor & Destructor Documentation

VectorComponentValueAccessor

(

int

index

)

determine the component to be accessed

Member Function Documentation

value_type operator()

(

ITERATOR const &

i

)

const

Read the current data item. The type ITERATOR::index_reference::value_type is automatically converted to value_type. In case of a conversion floating point -> integral this includes rounding and clipping.

value_type operator()	(	ITERATOR const &	i,
		OFFSET const &	diff
	)		const

Read the data item at an offset (can be 1D or 2D or higher order difference). The type ITERATOR::index_reference::value_type is automatically converted to value_type. In case of a conversion floating point -> integral this includes rounding and clipping.

void set	(	V	value,
		ITERATOR const &	i
	)		const

Write the current data item. The type V of the passed in value is automatically converted to value_type. In case of a conversion floating point -> integral this includes rounding and clipping.

void set	(	V	value,
		ITERATOR const &	i,
		OFFSET const &	diff
	)		const

Write the data item at an offset (can be 1D or 2D or higher order difference).. The type V of the passed in value is automatically converted to value_type. In case of a conversion floating point -> integral this includes rounding and clipping.

void setIndex

(

int

i

)

Reset the index to the given number.

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

• vigra/accessor.hxx