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prapi::texture::CircularLocalSampler< T, U > Class Template Reference

#include <CircularLocalSampler.h>

Inheritance diagram for prapi::texture::CircularLocalSampler< T, U >:

Detailed Description

template<class T, class U>
class prapi::texture::CircularLocalSampler< T, U >

CircularLocalSampler is a common superclass for all image transforms that work with a circular neighborhood.

"Circular neighborhood" is used to denote a situation where, instead of the traditional rectangular one, neighborhood pixels are defined to be the ones that lie at a certain distance from the center. The distance is also called "predicate". The number of samples at this distance and the predicate itself can be dynamically changed. In digital images, all pixels in a circular neighborhood do not necessarily match the pixel grid. Pixel values at these positions are obtained with bilinear interpolation or, if the interpolation flag is set to false, from the pixel nearest to the exact position.

Public Methods

CircularLocalSampler (unsigned int samples, double predicate)

Create a new CircularLocalSampler instance.

CircularLocalSampler (unsigned int samples=8, unsigned int predicate=1, bool interpolated=true)

Create a new CircularLocalSampler instance.

virtual ~CircularLocalSampler ()

void setPredicate (double p)

Set the predicate value.

void setPredicate (unsigned int p)

Set the predicate value, i.e.

void setPredicate (int p)

Set the predicate value.

double getPredicate (void)

Get the radius of the circular neighborhood.

void setInterpolated (bool intp)

Set the interpolation flag.

bool isInterpolated (void)

Get the interpolation flag.

void setSamples (unsigned int samples)

Set the number of samples in the circular neighborhood.

unsigned int getSamples ()

Get the number of samples in the circular neighborhood.

void setNeighborhood (unsigned int samples, double predicate)

Set the parameters of the circular neighborhood.

void setNeighborhood (unsigned int samples, unsigned int predicate)

Set the parameters of the circular neighborhood.

virtual T getValue (U center, util::List &surrounding)

Subclasses must implement this method to return a transformed value for a center pixel given a known circular neighborhood.

virtual util::Matrix< T > getTransformedImage (const util::Matrix &mat) throw (ImageTransformException&)

Goes through each matrix pixel, calculates the neighborhood values using the defined sample count and predicate, either with or without interpolation.

double getStartAngle () const

Get the angle at which the first neighbor is located.

void setStartAngle (double angle)

Set the angle of the first neighbor point.

Protected Methods

void updatePoints (void)

Update the precalculated point value tables.

Protected Attributes

double _dPredicate

The current predicate (radius), i.e.

unsigned int _uiPredicate

The predicate rounded to the closest integer larger than _dPredicate.

bool _bInterpolated

The interpolation flag.

unsigned int _uiSamples

The number of samples in the local neighborhood.

double _dStartAngle

The angle of the first neighbor.

prapi::graphics::Point< int > * _pPoints

A precalculated table of interpolation points.

prapi::graphics::Point< double > * _pOffsets

A precalculated table of interpolation offsets.

double * _dpMultipliers

Precalculated values for interpolation multiplication.

Constructor & Destructor Documentation

template<class T, class U>

prapi::texture::CircularLocalSampler< T, U >::CircularLocalSampler ( unsigned int samples,

double predicate

)

Create a new CircularLocalSampler instance.
Make sure the compiler understands you are giving the predicate as a floating point value. Otherwise, it may have difficulties in detecting whether this or the other constructor should be used. Example:
new CircularLocalSampler<int,int>(8,1.0);
Parameters:

predicate the sampling radius

samples the number of samples in the circular neighborhood

template<class T, class U>

prapi::texture::CircularLocalSampler< T, U >::CircularLocalSampler ( unsigned int samples = 8,

unsigned int predicate = 1,

bool interpolated = true

)

Create a new CircularLocalSampler instance.
Make sure the compiler understands you are giving the predicate as an unsigned integer Otherwise, it may have difficulties in detecting whether this or the other constructor should be used. Example:
new CircularLocalSampler<int,int>(8,1u);
Parameters:

samples the number of samples in the circular neighborhood

predicate the sampling radius

interpolated if true, bilinear interpolation is in use. Otherwise, nearest neighbor is used.

Member Function Documentation

template<class T, class U>

double prapi::texture::CircularLocalSampler< T, U >::getStartAngle ( ) const [inline]

Get the angle at which the first neighbor is located.
Angle is represented as radians in counter-clockwise direction. The direction of the positive x axis is 0. This value defaults to 0.

template<class T, class U>

util::Matrix< T > prapi::texture::CircularLocalSampler< T, U >::getTransformedImage ( const util::Matrix & mat ) throw (ImageTransformException&) [virtual]

Goes through each matrix pixel, calculates the neighborhood values using the defined sample count and predicate, either with or without interpolation.
For each neighborhood, calls getValue(U, List&) and stores the returned value into the transformed matrix. The size of the resulting matrix is smaller than the input due to border effects. If you set the radius of the neighborhood to 3, the width and height of the result matrix will be 4 (=(3-1)*2) pixels smaller than those of the input.
Parameters:

mat the input matrix

Returns:
the transformed matrix

Implements prapi::ImageTransform< T, U >.
Reimplemented in prapi::texture::GeneralLBP< T >, and prapi::texture::LBP8.

template<class T, class U>

virtual T prapi::texture::CircularLocalSampler< T, U >::getValue ( U center,

util::List & surrounding

) [inline, virtual]

Subclasses must implement this method to return a transformed value for a center pixel given a known circular neighborhood.
The default implementation returns 0. This method is called for each pixel in an matrix from getTransformedImage(Matrix&). For example, the local variance operator returns the variance of the values in surrounding. LBP, in turn, compares each value in surrounding to the value of the center pixel, and builds up a binary code that it then returns.
Parameters:

center the value of the current center pixel

surrounding the values of the surrounding pixels starting from horizontal x-axis direction (3 o'clock) and proceeding clockwise. The length of this list is equal to the number of samples set with the setSamples() method.

Returns:
a transformed value for the center pixel.

Reimplemented in prapi::texture::Contrast, prapi::texture::OpponentColorLBP< T >, and prapi::texture::Variance.

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setInterpolated ( bool intp ) [inline]

Set the interpolation flag.

Parameters:

intp if true, points that do not match pixels exactly are interpolated. If false, nearest pixels are used.

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setNeighborhood ( unsigned int samples,

unsigned int predicate

) [inline]

Set the parameters of the circular neighborhood.

Parameters:

samples the number of neighborhood samples (e.g. 8u)

the radius of the neighborhood (e.g. 2u)

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setNeighborhood ( unsigned int samples,

double predicate

) [inline]

Set the parameters of the circular neighborhood.

Parameters:

samples the number of neighborhood samples (e.g. 8u)

the radius of the neighborhood (e.g. 1.5)

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setPredicate ( int p ) [inline]

Set the predicate value.
This will update the precalculated point table.
Parameters:

p the new predicate. Must be larger than 0.

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setPredicate ( unsigned int p ) [inline]

Set the predicate value, i.e.
the radius of the neighborhood. This will update the precalculated point table. Example:
sampler.setPredicate(3u);
Parameters:

p the new predicate. Must be larger than 0.

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setPredicate ( double p ) [inline]

Set the predicate value.
This will update the precalculated point table. Example:
sampler.setPredicate(3u);
Parameters:

p the new predicate. Must be larger than 0.

template<class T, class U>

void prapi::texture::CircularLocalSampler< T, U >::setSamples ( unsigned int samples )

Set the number of samples in the circular neighborhood.
The precalculated point table will be updated.
Reimplemented in prapi::texture::LBP8.

Member Data Documentation

template<class T, class U>

double prapi::texture::CircularLocalSampler< T, U >::_dPredicate [protected]

The current predicate (radius), i.e.
the distance of the neighborhood from its center.

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

CircularLocalSampler.h

Public Methods
	CircularLocalSampler (unsigned int samples, double predicate)
	Create a new CircularLocalSampler instance.
	CircularLocalSampler (unsigned int samples=8, unsigned int predicate=1, bool interpolated=true)
	Create a new CircularLocalSampler instance.
virtual	~CircularLocalSampler ()
void	setPredicate (double p)
	Set the predicate value.
void	setPredicate (unsigned int p)
	Set the predicate value, i.e.
void	setPredicate (int p)
	Set the predicate value.
double	getPredicate (void)
	Get the radius of the circular neighborhood.
void	setInterpolated (bool intp)
	Set the interpolation flag.
bool	isInterpolated (void)
	Get the interpolation flag.
void	setSamples (unsigned int samples)
	Set the number of samples in the circular neighborhood.
unsigned int	getSamples ()
	Get the number of samples in the circular neighborhood.
void	setNeighborhood (unsigned int samples, double predicate)
	Set the parameters of the circular neighborhood.
void	setNeighborhood (unsigned int samples, unsigned int predicate)
	Set the parameters of the circular neighborhood.
virtual T	getValue (U center, util::List< U > &surrounding)
	Subclasses must implement this method to return a transformed value for a center pixel given a known circular neighborhood.
virtual util::Matrix< T >	getTransformedImage (const util::Matrix< U > &mat) throw (ImageTransformException&)
	Goes through each matrix pixel, calculates the neighborhood values using the defined sample count and predicate, either with or without interpolation.
double	getStartAngle () const
	Get the angle at which the first neighbor is located.
void	setStartAngle (double angle)
	Set the angle of the first neighbor point.
Protected Methods
void	updatePoints (void)
	Update the precalculated point value tables.
Protected Attributes
double	_dPredicate
	The current predicate (radius), i.e.
unsigned int	_uiPredicate
	The predicate rounded to the closest integer larger than _dPredicate.
bool	_bInterpolated
	The interpolation flag.
unsigned int	_uiSamples
	The number of samples in the local neighborhood.
double	_dStartAngle
	The angle of the first neighbor.
prapi::graphics::Point< int > *	_pPoints
	A precalculated table of interpolation points.
prapi::graphics::Point< double > *	_pOffsets
	A precalculated table of interpolation offsets.
double *	_dpMultipliers
	Precalculated values for interpolation multiplication.

prapi::texture::CircularLocalSampler< T, U > Class Template Reference

Detailed Description

template<class T, class U> class prapi::texture::CircularLocalSampler< T, U >

Public Methods

Protected Methods

Protected Attributes

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class T, class U>
class prapi::texture::CircularLocalSampler< T, U >