mrpt::vision::CFeature Class Reference

A generic 2D feature from an image, extracted with CFeatureExtraction Each feature may have one or more descriptors (see descriptors), in addition to an image patch. More...

#include <mrpt/vision/CFeature.h>

Inheritance diagram for mrpt::vision::CFeature:

List of all members.

Classes
struct	TDescriptors
	All the possible descriptors this feature may have. More...
Public Member Functions
bool	getFirstDescriptorAsMatrix (mrpt::math::CMatrixFloat &desc) const
	Return the first found descriptor, as a matrix.
float	patchCorrelationTo (const CFeature &oFeature) const
	Computes the normalized cross-correlation between the patches of this and another feature (normalized in the range [0,1], such as 0=best, 1=worst).
float	descriptorDistanceTo (const CFeature &oFeature, TDescriptorType descriptorToUse=descAny, bool normalize_distances=true) const
	Computes the Euclidean Distance between this feature's and other feature's descriptors, using the given descriptor or the first present one.
float	descriptorSIFTDistanceTo (const CFeature &oFeature, bool normalize_distances=true) const
	Computes the Euclidean Distance between "this" and the "other" descriptors.
float	descriptorSURFDistanceTo (const CFeature &oFeature, bool normalize_distances=true) const
	Computes the Euclidean Distance between "this" and the "other" descriptors.
float	descriptorSpinImgDistanceTo (const CFeature &oFeature, bool normalize_distances=true) const
	Computes the Euclidean Distance between "this" and the "other" descriptors.
float	descriptorPolarImgDistanceTo (const CFeature &oFeature, float &minDistAngle, bool normalize_distances=true) const
	Returns the minimum Euclidean Distance between "this" and the "other" polar image descriptor, for the best shift in orientation.
float	descriptorLogPolarImgDistanceTo (const CFeature &oFeature, float &minDistAngle, bool normalize_distances=true) const
	Returns the minimum Euclidean Distance between "this" and the "other" log-polar image descriptor, for the best shift in orientation.
TFeatureType	get_type () const
	Get the type of the feature.
	CFeature ()
	Constructor.
virtual	~CFeature ()
	Virtual destructor.
Public Attributes
float	x
float	y
	Coordinates in the image.
TFeatureID	ID
	ID of the feature.
CImage	patch
	A patch of the image surrounding the feature.
uint16_t	patchSize
	Size of the patch (patchSize x patchSize) (it must be an odd number).
TFeatureType	type
	Type of the feature: featNotDefined, featSIFT, featKLT, featHarris, featSURF, featBeacon.
TKLTFeatureStatus	KLT_status
	Status of the feature tracking process.
float	KLT_val
	Value of the goodness of the feature.
float	orientation
	Main orientation of the feature.
float	scale
	Feature scale into the scale space.
uint8_t	IDSourceImage
	ID of the image from which the feature was extracted.
struct MRPTDLLIMPEXP mrpt::vision::CFeature::TDescriptors	descriptors
	All the possible descriptors this feature may have.
Static Protected Member Functions
static float	internal_distanceBetweenPolarImages (const mrpt::math::CMatrix &desc1, const mrpt::math::CMatrix &desc2, float &minDistAngle, bool normalize_distances, bool dont_shift_angle)
	Internal function used by "descriptorLogPolarImgDistanceTo" and "descriptorPolarImgDistanceTo".
Friends
class	CFeatureList
class	CMatchedFeatureList

---

Detailed Description

A generic 2D feature from an image, extracted with CFeatureExtraction Each feature may have one or more descriptors (see descriptors), in addition to an image patch.

The (Euclidean) distance between descriptors in a pair of features can be computed with descriptorDistanceTo, while the similarity of the patches is given by patchCorrelationTo.

Definition at line 108 of file vision/CFeature.h.

---

Constructor & Destructor Documentation

mrpt::vision::CFeature::CFeature

(

)

Constructor.

virtual mrpt::vision::CFeature::~CFeature

(

)

[inline, virtual]

Virtual destructor.

Definition at line 203 of file vision/CFeature.h.

---

Member Function Documentation

float mrpt::vision::CFeature::descriptorDistanceTo	(	const CFeature &	oFeature,
		TDescriptorType	descriptorToUse = descAny,
		bool	normalize_distances = true
	)			const

Computes the Euclidean Distance between this feature's and other feature's descriptors, using the given descriptor or the first present one.

Note:

If descriptorToUse is not descAny and that descriptor is not present in one of the features, an exception will be raised.

See also:

patchCorrelationTo

float mrpt::vision::CFeature::descriptorLogPolarImgDistanceTo	(	const CFeature &	oFeature,
		float &	minDistAngle,
		bool	normalize_distances = true
	)			const

Returns the minimum Euclidean Distance between "this" and the "other" log-polar image descriptor, for the best shift in orientation.

Parameters:

	oFeature	The other feature to compare with.
	minDistAngle	The placeholder for the angle at which the smallest distance is found.

Returns:

The distance for the best orientation (minimum distance).

float mrpt::vision::CFeature::descriptorPolarImgDistanceTo	(	const CFeature &	oFeature,
		float &	minDistAngle,
		bool	normalize_distances = true
	)			const

Returns the minimum Euclidean Distance between "this" and the "other" polar image descriptor, for the best shift in orientation.

Parameters:

	oFeature	The other feature to compare with.
	minDistAngle	The placeholder for the angle at which the smallest distance is found.

Returns:

The distance for the best orientation (minimum distance).

float mrpt::vision::CFeature::descriptorSIFTDistanceTo	(	const CFeature &	oFeature,
		bool	normalize_distances = true
	)			const

Computes the Euclidean Distance between "this" and the "other" descriptors.

float mrpt::vision::CFeature::descriptorSpinImgDistanceTo	(	const CFeature &	oFeature,
		bool	normalize_distances = true
	)			const

Computes the Euclidean Distance between "this" and the "other" descriptors.

float mrpt::vision::CFeature::descriptorSURFDistanceTo	(	const CFeature &	oFeature,
		bool	normalize_distances = true
	)			const

Computes the Euclidean Distance between "this" and the "other" descriptors.

TFeatureType mrpt::vision::CFeature::get_type

(

)

const [inline]

Get the type of the feature.

Definition at line 196 of file vision/CFeature.h.

bool mrpt::vision::CFeature::getFirstDescriptorAsMatrix

(

mrpt::math::CMatrixFloat &

desc

)

const

Return the first found descriptor, as a matrix.

Returns:

false on error, i.e. there is no valid descriptor.

static float mrpt::vision::CFeature::internal_distanceBetweenPolarImages	(	const mrpt::math::CMatrix &	desc1,
		const mrpt::math::CMatrix &	desc2,
		float &	minDistAngle,
		bool	normalize_distances,
		bool	dont_shift_angle
	)			[static, protected]

Internal function used by "descriptorLogPolarImgDistanceTo" and "descriptorPolarImgDistanceTo".

float mrpt::vision::CFeature::patchCorrelationTo

(

const CFeature &

oFeature

)

const

Computes the normalized cross-correlation between the patches of this and another feature (normalized in the range [0,1], such as 0=best, 1=worst).

Note:

If this or the other features does not have patches or they are of different sizes, an exception will be raised.

See also:

descriptorDistanceTo

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Friends And Related Function Documentation

friend class CFeatureList [friend]

Definition at line 110 of file vision/CFeature.h.

friend class CMatchedFeatureList [friend]

Definition at line 111 of file vision/CFeature.h.

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Member Data Documentation

struct MRPTDLLIMPEXP mrpt::vision::CFeature::TDescriptors mrpt::vision::CFeature::descriptors

All the possible descriptors this feature may have.

TFeatureID mrpt::vision::CFeature::ID

ID of the feature.

Definition at line 117 of file vision/CFeature.h.

uint8_t mrpt::vision::CFeature::IDSourceImage

ID of the image from which the feature was extracted.

Definition at line 125 of file vision/CFeature.h.

TKLTFeatureStatus mrpt::vision::CFeature::KLT_status

Status of the feature tracking process.

Definition at line 121 of file vision/CFeature.h.

float mrpt::vision::CFeature::KLT_val

Value of the goodness of the feature.

Definition at line 122 of file vision/CFeature.h.

float mrpt::vision::CFeature::orientation

Main orientation of the feature.

Definition at line 123 of file vision/CFeature.h.

CImage mrpt::vision::CFeature::patch

A patch of the image surrounding the feature.

Definition at line 118 of file vision/CFeature.h.

uint16_t mrpt::vision::CFeature::patchSize

Size of the patch (patchSize x patchSize) (it must be an odd number).

Definition at line 119 of file vision/CFeature.h.

float mrpt::vision::CFeature::scale

Feature scale into the scale space.

Definition at line 124 of file vision/CFeature.h.

TFeatureType mrpt::vision::CFeature::type

Type of the feature: featNotDefined, featSIFT, featKLT, featHarris, featSURF, featBeacon.

Definition at line 120 of file vision/CFeature.h.

float mrpt::vision::CFeature::x

Definition at line 116 of file vision/CFeature.h.

float mrpt::vision::CFeature::y

Coordinates in the image.

Definition at line 116 of file vision/CFeature.h.