eVision::EHarrisCornerDetector Class Reference

Manages a complete context for the Harris corner detector. More...

#include <eVision/EasyImage/EHarrisCornerDetector.h>

Collaboration diagram for eVision::EHarrisCornerDetector:

Public Member Functions
	EHarrisCornerDetector ()
	Constructs a EHarrisCornerDetector object initialized to its default values.
virtual	~EHarrisCornerDetector () throw ()
void	SetIntegrationScale (float integrationScale)
	The integration scale.
float	GetIntegrationScale () const
	The integration scale.
void	SetThreshold (float threshold)
	Threshold on the cornerness measure for a pixel to be considered as a corner.
float	GetThreshold () const
	Threshold on the cornerness measure for a pixel to be considered as a corner.
void	SetSubpixelPrecisionEnabled (bool subpixelEnabled)
	Sets whether the sub-pixel interpolation is enabled.
bool	GetSubpixelPrecisionEnabled () const
	Returns whether the sub-pixel interpolation is enabled.
void	SetDerivationScale (float derivationScale)
	Sets the derivation scale.
float	GetDerivationScale () const
	Returns the current derivation scale.
void	SetThresholdingMode (eVision::EHarrisThresholdingMode mode)
	Thresholding mode for the cornerness measure.
eVision::EHarrisThresholdingMode	GetThresholdingMode () const
	Thresholding mode for the cornerness measure.
void	SetGradientNormalizationEnabled (bool isEnabled)
	Sets whether the gradient is normalized before the computation of the cornerness measure.
bool	GetGradientNormalizationEnabled () const
	Sets whether the gradient is normalized before the computation of the cornerness measure.
void	Apply (const eVision::EROIBW8 &source, eVision::EHarrisInterestPoints &interestPoints)
	Apply the Harris corner detector on an image/ROI.
	EHarrisCornerDetector (CppWrapperInternal::InternalConstructor)

Public Attributes
CppWrapperInternal::WrappedClass	wrappedClass_

Detailed Description

Manages a complete context for the Harris corner detector.

This implementation of the Harris corner detector operates exclusively on a grayscale BW8 images.

License(s): EasyImage

Constructor & Destructor Documentation

EHarrisCornerDetector() [1/2]

eVision::EHarrisCornerDetector::EHarrisCornerDetector

(

)

Constructs a EHarrisCornerDetector object initialized to its default values.

~EHarrisCornerDetector()

eVision::EHarrisCornerDetector::~EHarrisCornerDetector ( ) throw (  )

virtual

EHarrisCornerDetector() [2/2]

eVision::EHarrisCornerDetector::EHarrisCornerDetector

(

CppWrapperInternal::InternalConstructor

)

Member Function Documentation

Apply()

void eVision::EHarrisCornerDetector::Apply	(	const eVision::EROIBW8 &	source,
		eVision::EHarrisInterestPoints &	interestPoints )

Apply the Harris corner detector on an image/ROI.

Parameters

source	The source image/ROI.
interestPoints	The container in which to store the interest points.

GetDerivationScale()

float eVision::EHarrisCornerDetector::GetDerivationScale

(

)

const

Returns the current derivation scale.

GetGradientNormalizationEnabled()

bool eVision::EHarrisCornerDetector::GetGradientNormalizationEnabled

(

)

const

Sets whether the gradient is normalized before the computation of the cornerness measure.

If this flag is enabled, the values of the X-gradient and of the Y-gradient are first divided by their maximum absolute value (in the internal computations). This results in a cornerness measure that is roughly distributed around the value 1. If this flag is disabled, the cornerness measure will be much greater.

GetIntegrationScale()

float eVision::EHarrisCornerDetector::GetIntegrationScale

(

)

const

The integration scale.

The integration scale is the standard deviation of the Gaussian filter that is used for scale analysis.

GetSubpixelPrecisionEnabled()

bool eVision::EHarrisCornerDetector::GetSubpixelPrecisionEnabled

(

)

const

Returns whether the sub-pixel interpolation is enabled.

GetThreshold()

float eVision::EHarrisCornerDetector::GetThreshold

(

)

const

Threshold on the cornerness measure for a pixel to be considered as a corner.

If the threshold mode is set to EHarrisThresholdingMode::EHarrisThresholdingMode_Absolute, the threshold value is interpreted as an absolute threshold on the cornerness. In this case, the threshold must be a strictly positive real value.

If the threshold mode is set to EHarrisThresholdingMode::EHarrisThresholdingMode_Relative, the threshold is expressed as a fraction ranging from 0 to 1 of the maximum value of the cornerness of the source image.

GetThresholdingMode()

eVision::EHarrisThresholdingMode eVision::EHarrisCornerDetector::GetThresholdingMode

(

)

const

Thresholding mode for the cornerness measure.

SetDerivationScale()

void eVision::EHarrisCornerDetector::SetDerivationScale

(

float

derivationScale

)

Sets the derivation scale.

Parameters

derivationScale

The scale of interest.

The derivation scale is the standard deviation of the Gaussian Filter used for the noise reduction during the computation of the gradient.

Whenever the integration scale is set through EHarrisCornerDetector::SetIntegrationScale, the derivation scale is reset to its default value, 0.7 * integrationScale. This is a recommended value, as suggested by the literature.

SetGradientNormalizationEnabled()

void eVision::EHarrisCornerDetector::SetGradientNormalizationEnabled

(

bool

isEnabled

)

Sets whether the gradient is normalized before the computation of the cornerness measure.

Parameters

isEnabled

Whether to enable the gradient normalization or not.

If this flag is enabled, the values of the X-gradient and of the Y-gradient are first divided by their maximum absolute value (in the internal computations). This results in a cornerness measure that is roughly distributed around the value 1. If this flag is disabled, the cornerness measure will be much greater.

SetIntegrationScale()

void eVision::EHarrisCornerDetector::SetIntegrationScale

(

float

integrationScale

)

The integration scale.

Parameters

integrationScale

The scale of interest.

The integration scale is the standard deviation of the Gaussian filter that is used for scale analysis.

SetSubpixelPrecisionEnabled()

void eVision::EHarrisCornerDetector::SetSubpixelPrecisionEnabled

(

bool

subpixelEnabled

)

Sets whether the sub-pixel interpolation is enabled.

Parameters

subpixelEnabled

Whether to enable sub-pixel precision or not.

When this flag is enabled, a sub-pixel interpolation is carried on so as to improve the accuracy of the location of the corners, to the expense of a loss of speed.

SetThreshold()

void eVision::EHarrisCornerDetector::SetThreshold

(

float

threshold

)

Threshold on the cornerness measure for a pixel to be considered as a corner.

Parameters

threshold

The value of the threshold.

If the threshold mode is set to EHarrisThresholdingMode::EHarrisThresholdingMode_Absolute, the threshold value is interpreted as an absolute threshold on the cornerness. In this case, the threshold must be a strictly positive real value.

If the threshold mode is set to EHarrisThresholdingMode::EHarrisThresholdingMode_Relative, the threshold is expressed as a fraction ranging from 0 to 1 of the maximum value of the cornerness of the source image.

SetThresholdingMode()

void eVision::EHarrisCornerDetector::SetThresholdingMode

(

eVision::EHarrisThresholdingMode

mode

)

Thresholding mode for the cornerness measure.

Parameters

mode	The thresholding mode.

Member Data Documentation

wrappedClass_

CppWrapperInternal::WrappedClass eVision::EHarrisCornerDetector::wrappedClass_