Generate transfer functions to be applied in the fourier domain. More...

#include <TransferFunctionGenerator.h>

Public Member Functions
	TransferFunctionGenerator ()
	Constructor.

	~TransferFunctionGenerator ()
	Destructor.

Static Public Member Functions
static int	GetScaleFactors (int width, int height, double &xFactor, double &yFactor)
	gets factors for scaling coordinates in Fourier domain More...

static ArrayGrid< double > *	GenerateHighPassTransferFunction (int width, int height, double x1, double x2)
	Generates a highpass transfer function as an ArrayGrid object. More...

static ArrayGrid< double > *	GenerateLowPassTransferFunction (int width, int height, double x1, double x2)
	Generates a lowpass transfer function as an ArrayGrid object. More...

static FFTBand *	GenerateOrientedTransferFunction (int width, int height, int orientationIndex, int maxNrOfOrientations, bool isForward, common::NumberMode mode=common::MODE_REAL)
	Generates a oriented transfer function as an ArrayGrid object. More...

static void	HighFrequencyCrossMask (FFTBand *inoutGrid, int nrBands)
	Trick to distribute highest frequencies over set of bands. More...

static ArrayGrid< double > *	GenerateLogRadiusBand (int width, int height, double centerFrequency, double bandWidth)
	Generates a LogGaussian axially symmetric transfer function Help function for GenerateLogGaborBandTransferFunction. More...

static ArrayGrid< double > *	GenerateGaussianAngularBand (int width, int height, double centerAngle, double angleSpread)
	Generates a angular Gaussian transfer function Help function for GenerateLogGaborBandTransferFunction. More...

static ArrayGrid< double > *	GenerateLogGaborBandTransferFunction (int width, int height, double centerFrequency, double radialWidth, double centerAngle, double angleSpread)
	Generates a LogGabor transfer function Source: Peter Kovesi: http://www.csse.uwa.edu.au/~pk/Research/MatlabFns/PhaseCongruency/Docs/convexpl.html. More...

static ArrayGrid< double > *	GenerateAxisSuppressTransferFunction (int width, int height, int axisWidth, double x1, double x2)
	Generates a transfer function to suppress frequencies on the axes. More...

static ArrayGrid< double > *	GenerateAxisExtractTransferFunction (int width, int height, int axisWidth)

static ArrayGrid< double > *	ConvertTransferFunctionToFilterKernel (FFTBand *pTransferFunction, common::NumberMode mode=common::MODE_REAL)
	Converts a Fourier domain transfer function to a filter kernel. More...

static ArrayGrid< double > *	ConvertTransferFunctionToFilterKernel (ArrayGrid< double > *pTransferFunction, common::NumberMode mode=common::MODE_REAL)
	Converts a Fourier domain transfer function to a filter kernel. More...

Detailed Description

Generate transfer functions to be applied in the fourier domain.

Member Function Documentation

static ArrayGrid<double>* stira::fouriertools::TransferFunctionGenerator::ConvertTransferFunctionToFilterKernel	(	FFTBand *	pTransferFunction,
		common::NumberMode	mode = `common::MODE_REAL`
	)

static

Converts a Fourier domain transfer function to a filter kernel.

Warning: the inverse Fourier Transform is applied to pTransferFunction, so take that into account when using this data after applying this function

Parameters

pTransferFunction	the transfer function to be converted
mode	tells if the real or the imaginary values are taken after the Inverse Fourier Transform is applied to the transfer function

static ArrayGrid<double>* stira::fouriertools::TransferFunctionGenerator::ConvertTransferFunctionToFilterKernel	(	ArrayGrid< double > *	pTransferFunction,
		common::NumberMode	mode = `common::MODE_REAL`
	)

static

Converts a Fourier domain transfer function to a filter kernel.

Parameters

pTransferFunction	the transfer function to be converted
mode	tells if the real or the imaginary values are taken after the Inverse Fourier Transform is applied to the transfer function

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateAxisSuppressTransferFunction	(	int	width,
		int	height,
		int	axisWidth,
		double	x1,
		double	x2
	)

static

Generates a transfer function to suppress frequencies on the axes.

Parameters

width	width of the grid with the transfer function
height	height of the grid with the transfer function
axisWidth	width around the axis to suppress
x1	distance from DC up to which the axis frequencies are not suppressed
x2	distance from DC beyond which all frequencies are suppressed

Returns: grid with transfer function

References stira::imagedata::ArrayGrid< T >::SetValue().

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateGaussianAngularBand	(	int	width,
		int	height,
		double	centerAngle,
		double	angleSpread
	)

static

Generates a angular Gaussian transfer function Help function for GenerateLogGaborBandTransferFunction.

Parameters

width	width of the grid with the transfer function
height	height of the grid with the transfer function
centerAngle	angle on which the maximum transfer occurs
angleSpread	angular width of the transfer band

Returns: grid with transfer function

References stira::imagedata::ArrayGrid< T >::SetValue().

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateHighPassTransferFunction	(	int	width,
		int	height,
		double	x1,
		double	x2
	)

static

Generates a highpass transfer function as an ArrayGrid object.

Parameters

width	width of grid to be generated
height	height of grid to be generated
x1	lowpass frequency (from here to DC, all frequencies are 0)
x2	highpass frequency (from here to the edges, all frequencies are 1)

Returns: grid with transfer function

References stira::imagedata::ArrayGrid< T >::SetValue().

Referenced by stira::steerable::PyramidComplex::Decompose(), stira::steerable::PyramidReal::Decompose(), stira::steerable::PyramidReal::Reconstruct(), and stira::steerable::PyramidComplex::Reconstruct().

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateLogGaborBandTransferFunction	(	int	width,
		int	height,
		double	centerFrequency,
		double	radialWidth,
		double	centerAngle,
		double	angleSpread
	)

static

Generates a LogGabor transfer function Source: Peter Kovesi: http://www.csse.uwa.edu.au/~pk/Research/MatlabFns/PhaseCongruency/Docs/convexpl.html.

Parameters

width	width of the grid with the transfer function
height	height of the grid with the transfer function
centerFrequency	distance from DC at which the maximum transfer occurs
radialWidth	radial width of the transfer band
centerAngle	angle on which the maximum transfer occurs
angleSpread	angular width of the transfer band

Returns: grid with transfer function

References stira::fouriertools::FFTBand::ApplyInverseTransform(), stira::fouriertools::FFTBand::ConvertToImaginaryGrid(), stira::fouriertools::FFTBand::ConvertToRealGrid(), and stira::imagedata::ArrayGrid< T >::MultiplyWith().

Referenced by stira::filter::LogGabor::Run().

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateLogRadiusBand	(	int	width,
		int	height,
		double	centerFrequency,
		double	bandWidth
	)

static

Generates a LogGaussian axially symmetric transfer function Help function for GenerateLogGaborBandTransferFunction.

Parameters

width	width of the grid with the transfer function
height	height of the grid with the transfer function
centerFrequency	distance from DC at which the maximum transfer occurs
bandWidth	width of the transfer band

Returns: grid with transfer function

References stira::imagedata::ArrayGrid< T >::SetValue().

ArrayGrid< double > * stira::fouriertools::TransferFunctionGenerator::GenerateLowPassTransferFunction	(	int	width,
		int	height,
		double	x1,
		double	x2
	)

static

Generates a lowpass transfer function as an ArrayGrid object.

Parameters

width	width of grid to be generated
height	height of grid to be generated
x1	lowpass frequency (from here to DC, all frequencies are 1)
x2	highpass frequency (from here to the edges, all frequencies are 0)

Returns: grid with transfer function

References stira::imagedata::ArrayGrid< T >::SetValue().

Referenced by stira::steerable::PyramidMaster< T >::ExtractL(), stira::steerable::PyramidMaster< T >::ExtractL0(), stira::steerable::PyramidMaster< T >::ReconstructL(), stira::steerable::PyramidMaster< T >::ReconstructL0(), and stira::fouriertools::FFT::SuppressOuterFrequencies().

FFTBand * stira::fouriertools::TransferFunctionGenerator::GenerateOrientedTransferFunction	(	int	width,
		int	height,
		int	orientationIndex,
		int	maxNrOfOrientations,
		bool	isForward,
		common::NumberMode	mode = `common::MODE_REAL`
	)

static

Generates a oriented transfer function as an ArrayGrid object.

Parameters

width	width of grid to be generated
height	height of grid to be generated
orientationIndex	number of the orientation to consider now
maxNrOfOrientations	maximum number of orientations in this decomposition
isForward	flag whether this transform is forward transform (if false; is backward transform)
mode	enum whether the transfer function needs to produce a real or complex valued response

Returns: grid with transfer function

References stira::common::MathUtils::Factorial(), and stira::fouriertools::FFTBand::SetValue().

Referenced by stira::steerable::PyramidMaster< T >::ExtractB(), stira::steerable::PyramidMaster< T >::ExtractB0(), stira::steerable::PyramidMaster< T >::ReconstructB(), and stira::steerable::PyramidMaster< T >::ReconstructB0().

int stira::fouriertools::TransferFunctionGenerator::GetScaleFactors	(	int	width,
		int	height,
		double &	xFactor,
		double &	yFactor
	)

static

gets factors for scaling coordinates in Fourier domain

Parameters

width	in: width of the grid
height	in: height of the grid
xFactor	out: scaling factor in x direction
yFactor	out: scaling factor in y direction

void stira::fouriertools::TransferFunctionGenerator::HighFrequencyCrossMask	(	FFTBand *	inoutGrid,
		int	nrBands
	)

static

Trick to distribute highest frequencies over set of bands.

Parameters

inoutGrid	transfer function to be masked (is input as well as output)
nrBands	nr of bands over wich to distribute the energy of this frequencies

Returns: grid with transfer function

References stira::fouriertools::FFTBand::GetHeight(), stira::fouriertools::FFTBand::GetWidth(), and stira::fouriertools::FFTBand::SetValue().

Referenced by stira::steerable::PyramidMaster< T >::ExtractB0(), and stira::steerable::PyramidMaster< T >::ReconstructB0().

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

fouriertools/fouriertools/TransferFunctionGenerator.h
fouriertools/fouriertools/TransferFunctionGenerator.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation