Keypoint Class Reference

The keypoint base class. More...

#include <SIFT/Keypoint.H>

Collaboration diagram for Keypoint:

Public Types
enum	CHANNEL { ORI, COL }
Public Member Functions
Constructors, destructor, copy, assigment

	Keypoint ()
	Uninitialized constructor; will net to call reset() later.
	Keypoint (const std::vector< byte > &features, const float x, const float y, const float s, const float o, const float dogmag)
	Constructor.
	Keypoint (const std::vector< byte > &features, const std::vector< byte > &colFeatures, const float x, const float y, const float s, const float o, const float dogmag, float oriWeight=1.0F, float colWeight=1.0F)
	Constructor with Color.
	Keypoint (const Keypoint &k)
	Copy-constructor.
void	reset (const std::vector< byte > &features, const float x, const float y, const float s, const float o, const float dogmag)
	Reset all internal values.
	~Keypoint ()
	Destructor.
Keypoint &	operator= (const Keypoint &k)
	Assignment.


int	distSquared (const rutz::shared_ptr< Keypoint > &k) const
	Compute squared distance between two keypoint descriptors.
int	maxDistSquared (CHANNEL channel=ORI) const
	Return the maximum possible dist sq between two feature vectors.
bool	operator< (const Keypoint &k) const
	Compares the magnitude of this keypoint to the given keypoint.
Protected Attributes
float	itsX
	our x coordinate
float	itsY
	our y coordinate
float	itsS
	our scale coordinate
float	itsO
	our orientation
float	itsM
	our DoG magnitude, for sorting
std::vector< byte >	itsOriFV
	our Ori feature vector
std::vector< byte >	itsColFV
	our color feature vector
float	itsOriWeight
	The weight for ori.
float	itsColWeight
	The weight for col.
Friends
std::istream &	operator>> (std::istream &is, Keypoint &k)
	Load a Keypoint from an istream.
std::ostream &	operator<< (std::ostream &os, const Keypoint &k)
	Save a Keypoint to an ostream.
Iterators and access functions
The iterators iterate on our feature vector data only, while the other access functions can be used to access the other data.
typedef std::vector< byte > ::iterator	iterator
	standard iterator
typedef std::vector< byte > ::const_iterator	const_iterator
	const iterator
const_iterator	begin (CHANNEL channel=ORI) const
	Returns a read-only iterator to the beginning of the feature vec data.
const_iterator	end (CHANNEL channel=ORI) const
	Returns a read-only iterator to one-past-the-end of the feature vec data.
iterator	beginw (CHANNEL channel=ORI)
	Returns a read-write iterator to the beginning of the feature vec data.
iterator	endw (CHANNEL channel=ORI)
	Returns a read-write iterator to one-past-the-end of the feature vec data.
float	getX () const
	x getter
float	getY () const
	y getter
float	getS () const
	scale getter
float	getO () const
	orientation getter
float	getM () const
	DoG magnitude getter.
uint	getFVlength (CHANNEL channel=ORI) const
	Return the length of this keypoint's feature vector.
byte	getFVelement (const uint index, CHANNEL channel=ORI) const
	Return the value of the feature vector at the given index.
std::vector< byte >	getOriFV ()
	Return a copy of the orientation feature vector.
std::vector< byte >	getColFV ()
	Return a copy of the color feature vector.

Detailed Description

The keypoint base class.

The sift keypoint feature descriptor 3D position (x, y, scale) Mean orientation, magnitude Feature vector

Definition at line 56 of file Keypoint.H.

Member Typedef Documentation

typedef std::vector<byte>::const_iterator Keypoint::const_iterator

const iterator

Definition at line 105 of file Keypoint.H.

typedef std::vector<byte>::iterator Keypoint::iterator

standard iterator

Definition at line 102 of file Keypoint.H.

Constructor & Destructor Documentation

Keypoint::Keypoint ( )

Uninitialized constructor; will net to call reset() later.

Definition at line 51 of file Keypoint.C.

Keypoint::Keypoint	(	const std::vector< byte > &	features,
		const float	x,
		const float	y,
		const float	s,
		const float	o,
		const float	dogmag
	)

Constructor.

Definition at line 57 of file Keypoint.C.

Keypoint::Keypoint	(	const std::vector< byte > &	features,
		const std::vector< byte > &	colFeatures,
		const float	x,
		const float	y,
		const float	s,
		const float	o,
		const float	dogmag,
		float	oriWeight = `1.0F`,
		float	colWeight = `1.0F`
	)

Constructor with Color.

Definition at line 68 of file Keypoint.C.

Keypoint::Keypoint ( const Keypoint & k )

Copy-constructor.

Definition at line 81 of file Keypoint.C.

Keypoint::~Keypoint ( )

Destructor.

Definition at line 105 of file Keypoint.C.

Member Function Documentation

Keypoint::const_iterator Keypoint::begin ( CHANNEL channel = ORI ) const [inline]

Returns a read-only iterator to the beginning of the feature vec data.

Definition at line 198 of file Keypoint.H.

References itsColFV, and itsOriFV.

Referenced by distSquared().

Keypoint::iterator Keypoint::beginw ( CHANNEL channel = ORI ) [inline]

Returns a read-write iterator to the beginning of the feature vec data.

Definition at line 223 of file Keypoint.H.

References itsColFV, and itsOriFV.

int Keypoint::distSquared ( const rutz::shared_ptr< Keypoint > & k ) const [inline]

Compute squared distance between two keypoint descriptors.

Comparisons and feature distance computation

Definition at line 290 of file Keypoint.H.

References ASSERT, begin(), end(), itsColFV, itsColWeight, itsOriFV, and itsOriWeight.

Keypoint::const_iterator Keypoint::end ( CHANNEL channel = ORI ) const [inline]

Returns a read-only iterator to one-past-the-end of the feature vec data.

Definition at line 210 of file Keypoint.H.

References itsColFV, and itsOriFV.

Referenced by distSquared().

Keypoint::iterator Keypoint::endw ( CHANNEL channel = ORI ) [inline]

Returns a read-write iterator to one-past-the-end of the feature vec data.

Definition at line 235 of file Keypoint.H.

References itsColFV, and itsOriFV.

std::vector<byte> Keypoint::getColFV ( ) [inline]

Return a copy of the color feature vector.

Definition at line 144 of file Keypoint.H.

References itsColFV.

byte Keypoint::getFVelement	(	const uint	index,
		CHANNEL	channel = `ORI`
	)			const `[inline]`

Return the value of the feature vector at the given index.

Definition at line 275 of file Keypoint.H.

References ASSERT, itsColFV, and itsOriFV.

uint Keypoint::getFVlength ( CHANNEL channel = ORI ) const [inline]

Return the length of this keypoint's feature vector.

Definition at line 263 of file Keypoint.H.

References itsColFV, and itsOriFV.

float Keypoint::getM ( ) const [inline]

DoG magnitude getter.

Definition at line 260 of file Keypoint.H.

References itsM.

float Keypoint::getO ( ) const [inline]

orientation getter

Definition at line 257 of file Keypoint.H.

References itsO.

std::vector<byte> Keypoint::getOriFV ( ) [inline]

Return a copy of the orientation feature vector.

Definition at line 141 of file Keypoint.H.

References itsOriFV.

float Keypoint::getS ( ) const [inline]

scale getter

Definition at line 254 of file Keypoint.H.

References itsS.

float Keypoint::getX ( ) const [inline]

x getter

Definition at line 248 of file Keypoint.H.

References itsX.

float Keypoint::getY ( ) const [inline]

y getter

Definition at line 251 of file Keypoint.H.

References itsY.

int Keypoint::maxDistSquared ( CHANNEL channel = ORI ) const [inline]

Return the maximum possible dist sq between two feature vectors.

This is just a function of the size of our feature vector

Definition at line 324 of file Keypoint.H.

References itsColFV, and itsOriFV.

bool Keypoint::operator< ( const Keypoint & k ) const [inline]

Compares the magnitude of this keypoint to the given keypoint.

This is useful, for example, to use std::sort() on an std::vector< rutz::shared_ptr<Keypoint> >. Just remember that the comparison is based on the magnitude of the DoG only, not on any other internal data of the Keypoint.

Definition at line 336 of file Keypoint.H.

References itsM.

Keypoint & Keypoint::operator= ( const Keypoint & k )

Assignment.

Definition at line 97 of file Keypoint.C.

References itsM, itsO, itsOriFV, itsS, itsX, and itsY.