Class that compares two sets of features by using a multiscale representation of the features inside a pyramid. Each level of the pyramid offers information about the similarity of the two feature sets. More...

#include <pyramid_feature_matching.h>

Inheritance diagram for pcl::PyramidFeatureHistogram< PointFeature >:

[legend]

List of all members.

Classes
struct	PyramidFeatureHistogramLevel
	Structure for representing a single pyramid histogram level. More...
Public Types
typedef boost::shared_ptr < const pcl::PointRepresentation < PointFeature > >	FeatureRepresentationConstPtr
typedef boost::shared_ptr < PyramidFeatureHistogram < PointFeature > >	Ptr
typedef Ptr	PyramidFeatureHistogramPtr
Public Member Functions
void	compute ()
	The central method for inserting the feature set inside the pyramid and obtaining the complete pyramid.
std::vector< std::pair< float, float > >	getInputDimensionRange ()
	Method for retrieving the input dimension range vector.
FeatureRepresentationConstPtr const	getPointRepresentation ()
	Get a pointer to the feature representation used when converting features into k-D vectors.
std::vector< std::pair< float, float > >	getTargetDimensionRange ()
	Method for retrieving the target dimension range vector.
bool	isComputed ()
	Checks whether the pyramid histogram has been computed.
	PyramidFeatureHistogram ()
	Empty constructor that instantiates the feature representation variable.
void	setInputDimensionRange (std::vector< std::pair< float, float > > &dimension_range_input)
	Method for setting the input dimension range parameter.
void	setPointRepresentation (const FeatureRepresentationConstPtr &feature_representation)
	Provide a pointer to the feature representation to use to convert features to k-D vectors.
void	setTargetDimensionRange (std::vector< std::pair< float, float > > &dimension_range_target)
	Method to set the target dimension range parameter.
Static Public Member Functions
static float	comparePyramidFeatureHistograms (const PyramidFeatureHistogramPtr &pyramid_a, const PyramidFeatureHistogramPtr &pyramid_b)
	Static method for comparing two pyramid histograms that returns a floating point value between 0 and 1, representing the similiarity between the feature sets on which the two pyramid histograms are based.
Private Member Functions
void	addFeature (std::vector< float > &feature)
	Adds a feature vector to its corresponding bin at each level in the pyramid.
unsigned int &	at (std::vector< size_t > &access, size_t &level)
	Access the pyramid bin given the position of the bin at the given pyramid level and the pyramid level.
unsigned int &	at (std::vector< float > &feature, size_t &level)
	Access the pyramid bin given a feature vector and the pyramid level.
void	convertFeatureToVector (const PointFeature &feature, std::vector< float > &feature_vector)
	Converts a feature in templated form to an STL vector. This is the point where the conversion from the input dimension range to the target dimension range is done.
bool	initializeHistogram ()
	Checks for input inconsistencies and initializes the underlying data structures.
Private Attributes
std::vector< std::pair< float, float > >	dimension_range_input_
std::vector< std::pair< float, float > >	dimension_range_target_
FeatureRepresentationConstPtr	feature_representation_
std::vector < PyramidFeatureHistogramLevel >	hist_levels
bool	is_computed_
size_t	nr_dimensions
size_t	nr_features
size_t	nr_levels

Detailed Description

template<typename PointFeature>
class pcl::PyramidFeatureHistogram< PointFeature >

Class that compares two sets of features by using a multiscale representation of the features inside a pyramid. Each level of the pyramid offers information about the similarity of the two feature sets.

Note:: Works with any Point/Feature type which has a PointRepresentation implementation; The only parameters it needs are the input dimension ranges and the output dimension ranges. The input dimension ranges represent the ranges in which each dimension of the feature vector lies. As described in the paper, a minimum inter-vector distance of sqrt(nr_dims)/2 is needed. As such, the target dimension range parameter is used in order to augment/reduce the range for each dimension in order to obtain the necessary minimal inter-vector distance and to add/subtract weight to/from certain dimensions of the feature vector.

Follows the algorithm presented in the publication: Grauman, K. & Darrell, T. The Pyramid Match Kernel: Discriminative Classification with Sets of Image Features Tenth IEEE International Conference on Computer Vision ICCV05 Volume 1 October 2005

Author:: Alexandru-Eugen Ichim

Definition at line 65 of file pyramid_feature_matching.h.

Member Typedef Documentation

template<typename PointFeature>

typedef boost::shared_ptr<const pcl::PointRepresentation<PointFeature> > pcl::PyramidFeatureHistogram< PointFeature >::FeatureRepresentationConstPtr

Definition at line 72 of file pyramid_feature_matching.h.

template<typename PointFeature>

typedef boost::shared_ptr<PyramidFeatureHistogram<PointFeature> > pcl::PyramidFeatureHistogram< PointFeature >::Ptr

Definition at line 70 of file pyramid_feature_matching.h.

template<typename PointFeature>

typedef Ptr pcl::PyramidFeatureHistogram< PointFeature >::PyramidFeatureHistogramPtr

Definition at line 71 of file pyramid_feature_matching.h.

Constructor & Destructor Documentation

template<typename PointFeature >

pcl::PyramidFeatureHistogram< PointFeature >::PyramidFeatureHistogram ( )

Empty constructor that instantiates the feature representation variable.

Definition at line 126 of file pyramid_feature_matching.hpp.

Member Function Documentation

template<typename PointFeature >

void pcl::PyramidFeatureHistogram< PointFeature >::addFeature ( std::vector< float > & feature ) [private]

Adds a feature vector to its corresponding bin at each level in the pyramid.

Definition at line 303 of file pyramid_feature_matching.hpp.

template<typename PointFeature >

unsigned int & pcl::PyramidFeatureHistogram< PointFeature >::at	(	std::vector< size_t > &	access,
		size_t &	level
	)		`[inline, private]`

Access the pyramid bin given the position of the bin at the given pyramid level and the pyramid level.

Parameters:

access	index of the bin at the respective level
level	the level in the pyramid

Definition at line 216 of file pyramid_feature_matching.hpp.

template<typename PointFeature >

unsigned int & pcl::PyramidFeatureHistogram< PointFeature >::at	(	std::vector< float > &	feature,
		size_t &	level
	)		`[inline, private]`

Access the pyramid bin given a feature vector and the pyramid level.

Parameters:

feature	the feature in vectorized form
level	the level in the pyramid

Definition at line 245 of file pyramid_feature_matching.hpp.

template<typename PointFeature >

float pcl::PyramidFeatureHistogram< PointFeature >::comparePyramidFeatureHistograms	(	const PyramidFeatureHistogramPtr &	pyramid_a,
		const PyramidFeatureHistogramPtr &	pyramid_b
	)		`[static]`

Static method for comparing two pyramid histograms that returns a floating point value between 0 and 1, representing the similiarity between the feature sets on which the two pyramid histograms are based.

Parameters:

pyramid_a	Pointer to the first pyramid to be compared (needs to be computed already).
pyramid_b	Pointer to the second pyramid to be compared (needs to be computed already).

Definition at line 58 of file pyramid_feature_matching.hpp.

template<typename PointFeature >

void pcl::PyramidFeatureHistogram< PointFeature >::compute ( )

The central method for inserting the feature set inside the pyramid and obtaining the complete pyramid.

Definition at line 285 of file pyramid_feature_matching.hpp.

template<typename PointFeature >

void pcl::PyramidFeatureHistogram< PointFeature >::convertFeatureToVector	(	const PointFeature &	feature,
		std::vector< float > &	feature_vector
	)		`[private]`

Converts a feature in templated form to an STL vector. This is the point where the conversion from the input dimension range to the target dimension range is done.

Definition at line 269 of file pyramid_feature_matching.hpp.

template<typename PointFeature>

std::vector<std::pair<float, float> > pcl::PyramidFeatureHistogram< PointFeature >::getInputDimensionRange ( ) [inline]

Method for retrieving the input dimension range vector.

Definition at line 87 of file pyramid_feature_matching.h.

template<typename PointFeature>

FeatureRepresentationConstPtr const pcl::PyramidFeatureHistogram< PointFeature >::getPointRepresentation ( ) [inline]

Get a pointer to the feature representation used when converting features into k-D vectors.

Definition at line 108 of file pyramid_feature_matching.h.

template<typename PointFeature>

std::vector<std::pair<float, float> > pcl::PyramidFeatureHistogram< PointFeature >::getTargetDimensionRange ( ) [inline]

Method for retrieving the target dimension range vector.

Definition at line 98 of file pyramid_feature_matching.h.

template<typename PointFeature >

bool pcl::PyramidFeatureHistogram< PointFeature >::initializeHistogram ( ) [private]

Checks for input inconsistencies and initializes the underlying data structures.

Definition at line 149 of file pyramid_feature_matching.hpp.

template<typename PointFeature>

bool pcl::PyramidFeatureHistogram< PointFeature >::isComputed ( ) [inline]

Checks whether the pyramid histogram has been computed.

Definition at line 116 of file pyramid_feature_matching.h.

template<typename PointFeature>

void pcl::PyramidFeatureHistogram< PointFeature >::setInputDimensionRange ( std::vector< std::pair< float, float > > & dimension_range_input ) [inline]

Method for setting the input dimension range parameter.

Note:: Please check the PyramidHistogram class description for more details about this parameter.

Definition at line 82 of file pyramid_feature_matching.h.

template<typename PointFeature>

void pcl::PyramidFeatureHistogram< PointFeature >::setPointRepresentation ( const FeatureRepresentationConstPtr & feature_representation ) [inline]

Provide a pointer to the feature representation to use to convert features to k-D vectors.

Parameters:

feature_representation the const boost shared pointer to a PointRepresentation

Definition at line 104 of file pyramid_feature_matching.h.

template<typename PointFeature>

void pcl::PyramidFeatureHistogram< PointFeature >::setTargetDimensionRange ( std::vector< std::pair< float, float > > & dimension_range_target ) [inline]

Method to set the target dimension range parameter.