Detailed Description

The central class from which images can be analyzed in search of different kinds of interest points and descriptors computed for them.

To extract features from an image, create an instance of CFeatureExtraction, fill out its CFeatureExtraction::options field, including the algorithm to use (see CFeatureExtraction::TOptions::featsType), and call CFeatureExtraction::detectFeatures. This will return a set of features of the class mrpt::vision::CFeature, which include details for each interest point as well as the desired descriptors and/or patches.

By default, a 21x21 patch is extracted for each detected feature. If the patch is not needed, set patchSize to 0 in CFeatureExtraction::options

The implemented detection algorithms are (see CFeatureExtraction::TOptions::featsType):

KLT (Kanade-Lucas-Tomasi): A detector (no descriptor vector).
Harris: A detector (no descriptor vector).
BCD (Binary Corner Detector): A detector (no descriptor vector) (Not implemented yet).
SIFT: An implementation of the SIFT detector and descriptor. The implemention may be selected with CFeatureExtraction::TOptions::SIFTOptions::implementation.
SURF: OpenCV's implementation of SURF detector and descriptor.
The FAST feature detector (OpenCV's implementation)
The FASTER (9,10,12) detectors (Edward Rosten's libcvd implementation optimized for SSE2).

Additionally, given a list of interest points onto an image, the following descriptors can be computed for each point by calling CFeatureExtraction::computeDescriptors :

SIFT descriptor (Lowe's descriptors).
SURF descriptor (OpenCV's implementation - Requires OpenCV 1.1.0 from SVN or later).
Intensity-domain spin images (SpinImage): Creates a vector descriptor with the 2D histogram as a single row.
A circular patch in polar coordinates (Polar images): The matrix descriptor is a 2D polar image centered at the interest point.
A log-polar image patch (Log-polar images): The matrix descriptor is the 2D log-polar image centered at the interest point.

Apart from the normal entry point detectFeatures(), these other low-level static methods are provided for convenience:

Note: The descriptor "Intensity-domain spin images" is described in "A sparse texture representation using affine-invariant regions", S Lazebnik, C Schmid, J Ponce, 2003 IEEE Computer Society Conference on Computer Vision.

See also: mrpt::vision::CFeature

Definition at line 59 of file CFeatureExtraction.h.

#include <mrpt/vision/CFeatureExtraction.h>

Classes
struct	TOptions
	The set of parameters for all the detectors & descriptor algorithms. More...

Public Types
enum	TSIFTImplementation { LoweBinary = 0, CSBinary, VedaldiBinary, Hess, OpenCV }

Public Member Functions
	CFeatureExtraction ()
	Constructor. More...

virtual	~CFeatureExtraction ()
	Virtual destructor. More...

void	detectFeatures (const mrpt::utils::CImage &img, CFeatureList &feats, const unsigned int init_ID=0, const unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the method defined in TOptions. More...

void	computeDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &inout_features, TDescriptorType in_descriptor_list) const
	Compute one (or more) descriptors for the given set of interest points onto the image, which may have been filled out manually or from detectFeatures. More...

Static Public Member Functions
Static methods with low-level detector functionality
static void	detectFeatures_SSE2_FASTER9 (const mrpt::utils::CImage &img, TSimpleFeatureList &corners, const int threshold=20, bool append_to_list=false, uint8_t octave=0, std::vector< size_t > *out_feats_index_by_row=NULL)
	A SSE2-optimized implementation of FASTER-9 (requires img to be grayscale). More...

static void	detectFeatures_SSE2_FASTER10 (const mrpt::utils::CImage &img, TSimpleFeatureList &corners, const int threshold=20, bool append_to_list=false, uint8_t octave=0, std::vector< size_t > *out_feats_index_by_row=NULL)
	Just like detectFeatures_SSE2_FASTER9() for another version of the detector. More...

static void	detectFeatures_SSE2_FASTER12 (const mrpt::utils::CImage &img, TSimpleFeatureList &corners, const int threshold=20, bool append_to_list=false, uint8_t octave=0, std::vector< size_t > *out_feats_index_by_row=NULL)
	Just like detectFeatures_SSE2_FASTER9() for another version of the detector. More...

Public Attributes
TOptions	options
	Set all the parameters of the desired method here before calling "detectFeatures". More...

Private Member Functions
void	internal_computeSiftDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute the SIFT descriptor of the provided features into the input image. More...

void	internal_computeSurfDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute the SURF descriptor of the provided features into the input image. More...

void	internal_computeORBDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute the ORB descriptor of the provided features into the input image. More...

void	internal_computeSpinImageDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute the intensity-domain spin images descriptor of the provided features into the input image. More...

void	internal_computePolarImageDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute a polar-image descriptor of the provided features into the input image. More...

void	internal_computeLogPolarImageDescriptors (const mrpt::utils::CImage &in_img, CFeatureList &in_features) const
	Compute a log-polar image descriptor of the provided features into the input image. More...

void	extractFeaturesKLT (const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the KLT method. More...

void	extractFeaturesBCD (const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the BCD method. More...

void	extractFeaturesSIFT (const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the SIFT method. More...

void	extractFeaturesORB (const mrpt::utils::CImage &img, CFeatureList &feats, const unsigned int init_ID=0, const unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the ORB method. More...

void	extractFeaturesSURF (const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Extract features from the image based on the SURF method. More...

void	extractFeaturesFAST (const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI(), const mrpt::math::CMatrixBool *mask=NULL) const
	Extract features from the image based on the FAST method. More...

void	extractFeaturesFASTER_N (const int N, const mrpt::utils::CImage &img, CFeatureList &feats, unsigned int init_ID=0, unsigned int nDesiredFeatures=0, const TImageROI &ROI=TImageROI()) const
	Edward's "FASTER & Better" detector, N=9,10,12. More...

void *	my_scale_space_extrema (CFeatureList &featList, void dog_pyr, int octvs, int intvls, double contr_thr, int curv_thr, void storage) const
	Computes extrema in the scale space. More...

void	my_adjust_for_img_dbl (void *features) const
	Adjust scale if the image was initially doubled. More...

void	getTimesExtrema (void *dog_pyr, int octvs, int intvls, float row, float col, unsigned int &nMin, unsigned int &nMax) const
	Gets the number of times that a point in the image is higher or lower than the surroundings in the image-scale space. More...

double	getLaplacianValue (void *dog_pyr, int octvs, int intvls, float row, float col) const
	Computes the Laplacian value of the feature in the corresponing image in the pyramid. More...

void	insertCvSeqInCFeatureList (void *features, CFeatureList &list, unsigned int init_ID=0) const
	Append a sequence of openCV features into an MRPT feature list. More...

void	convertCvSeqInCFeatureList (void *features, CFeatureList &list, unsigned int init_ID=0, const TImageROI &ROI=TImageROI()) const
	Converts a sequence of openCV features into an MRPT feature list. More...

Member Enumeration Documentation

◆ TSIFTImplementation

enum mrpt::vision::CFeatureExtraction::TSIFTImplementation

Enumerator
LoweBinary
CSBinary
VedaldiBinary
Hess
OpenCV

Definition at line 62 of file CFeatureExtraction.h.

Constructor & Destructor Documentation

◆ CFeatureExtraction()

CFeatureExtraction::CFeatureExtraction ( )

Constructor.

Definition at line 26 of file CFeatureExtraction_common.cpp.

◆ ~CFeatureExtraction()

CFeatureExtraction::~CFeatureExtraction ( )

virtual

Virtual destructor.

Definition at line 33 of file CFeatureExtraction_common.cpp.

Member Function Documentation

◆ computeDescriptors()

void CFeatureExtraction::computeDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	inout_features,
		TDescriptorType	in_descriptor_list
	)		const

Compute one (or more) descriptors for the given set of interest points onto the image, which may have been filled out manually or from detectFeatures.

Parameters

in_img	(input) The image from where to compute the descriptors.
inout_features	(input/output) The list of features whose descriptors are going to be computed.
in_descriptor_list	(input) The bitwise OR of one or several descriptors defined in TDescriptorType.

Each value in "in_descriptor_list" represents one descriptor to be computed, for example:

// This call will compute both, SIFT and Spin-Image descriptors for a list of feature points lstFeats.

fext.computeDescriptors(img, lstFeats, descSIFT | descSpinImages );

Note: The SIFT descriptors for already located features can only be computed through the Hess and CSBinary implementations which may be specified in CFeatureExtraction::TOptions::SIFTOptions.; This call will also use additional parameters from options

Definition at line 208 of file CFeatureExtraction_common.cpp.

References mrpt::vision::descLogPolarImages, mrpt::vision::descORB, mrpt::vision::descPolarImages, mrpt::vision::descSIFT, mrpt::vision::descSpinImages, mrpt::vision::descSURF, MRPT_END, MRPT_START, and THROW_EXCEPTION_FMT.

Referenced by mrpt::slam::COccupancyGridMapFeatureExtractor::uncached_extractFeatures().

◆ convertCvSeqInCFeatureList()

void CFeatureExtraction::convertCvSeqInCFeatureList	(	void *	features,
		CFeatureList &	list,
		unsigned int	init_ID = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Converts a sequence of openCV features into an MRPT feature list.

Parameters

features	The sequence of features.
list	[in-out] The list of MRPT features.
init_ID	[in][optional] The initial ID for the features (default = 0).
ROI	[in][optional] The initial ID for the features (default = empty ROI -> not used).

Definition at line 670 of file CFeatureExtraction_SIFT.cpp.

References ASSERT_, mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), feature::d, feature::descr, mrpt::vision::featSIFT, feature::ori, mrpt::vision::CFeatureList::push_back(), feature::scl, THROW_EXCEPTION, feature::x, mrpt::vision::TImageROI::xMax, mrpt::vision::TImageROI::xMin, feature::y, mrpt::vision::TImageROI::yMax, and mrpt::vision::TImageROI::yMin.

◆ detectFeatures()

void CFeatureExtraction::detectFeatures	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		const unsigned int	init_ID = `0`,
		const unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

Extract features from the image based on the method defined in TOptions.

Parameters

img	(input) The image from where to extract the images.
feats	(output) A complete list of features (containing a patch for each one of them if options.patchsize > 0).
nDesiredFeatures	(op. input) Number of features to be extracted. Default: all possible.

See also: computeDescriptors

Definition at line 46 of file CFeatureExtraction_common.cpp.

Referenced by mrpt::maps::CLandmarksMap::loadSiftFeaturesFromImageObservation(), mrpt::vision::StereoObs2BRObs(), and mrpt::slam::COccupancyGridMapFeatureExtractor::uncached_extractFeatures().

◆ extractFeaturesBCD()

void CFeatureExtraction::extractFeaturesBCD	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Extract features from the image based on the BCD method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.
ROI	(op. input) Region of Interest. Default: All the image.

Definition at line 257 of file CFeatureExtraction_common.cpp.

References MRPT_UNUSED_PARAM, and THROW_EXCEPTION.

◆ extractFeaturesFAST()

void CFeatureExtraction::extractFeaturesFAST	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`,
		const mrpt::math::CMatrixBool *	mask = `NULL`
	)		const

private

Extract features from the image based on the FAST method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.

Definition at line 29 of file CFeatureExtraction_FAST.cpp.

References ASSERT_, mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), mrpt::utils::CImage::extract_patch(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::vision::featFAST, mrpt::math::CMatrixTemplate< T >::fillAll(), mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), mrpt::utils::CImage::KLT_response(), MRPT_END, MRPT_START, MRPT_UNUSED_PARAM, ones(), mrpt::vision::CFeatureList::push_back(), mrpt::utils::round(), mrpt::math::CMatrixTemplate< T >::set_unsafe(), and THROW_EXCEPTION.

◆ extractFeaturesFASTER_N()

void CFeatureExtraction::extractFeaturesFASTER_N	(	const int	N,
		const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Edward's "FASTER & Better" detector, N=9,10,12.

Definition at line 71 of file CFeatureExtraction_FASTER.cpp.

References mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), mrpt::utils::CImage::extract_patch(), fast_corner_detect_10(), fast_corner_detect_12(), fast_corner_detect_9(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::vision::featFASTER10, mrpt::vision::featFASTER12, mrpt::vision::featFASTER9, mrpt::math::CMatrixTemplate< T >::fillAll(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), MRPT_END, MRPT_START, MRPT_UNUSED_PARAM, mrpt::vision::TSimpleFeature_templ< PIXEL_COORD_TYPE >::pt, mrpt::vision::CFeatureList::push_back(), mrpt::vision::TSimpleFeature_templ< PIXEL_COORD_TYPE >::response, mrpt::utils::round(), mrpt::math::CMatrixTemplate< T >::set_unsafe(), and THROW_EXCEPTION.

◆ extractFeaturesKLT()

void CFeatureExtraction::extractFeaturesKLT	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Extract features from the image based on the KLT method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.

Definition at line 28 of file CFeatureExtraction_harris_KLT.cpp.

References mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), mrpt::utils::CImage::extract_patch(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::vision::featHarris, mrpt::vision::featKLT, mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), min, MRPT_END, MRPT_START, mrpt::vision::CFeatureList::push_back(), mrpt::utils::round(), mrpt::vision::status_TRACKED, mrpt::utils::CTicTac::Tac(), THROW_EXCEPTION, and mrpt::utils::CTicTac::Tic().

◆ extractFeaturesORB()

void CFeatureExtraction::extractFeaturesORB	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		const unsigned int	init_ID = `0`,
		const unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Extract features from the image based on the ORB method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.

Definition at line 26 of file CFeatureExtraction_ORB.cpp.

References mrpt::vision::CFeatureList::clear(), mrpt::utils::CImage::extract_patch(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::vision::featORB, mrpt::math::CMatrixTemplate< T >::fillAll(), mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), min, MRPT_END, MRPT_START, MRPT_UNUSED_PARAM, mrpt::vision::CFeatureList::push_back(), mrpt::vision::CFeatureList::resize(), mrpt::utils::round(), mrpt::math::CMatrixTemplate< T >::set_unsafe(), mrpt::vision::CFeatureList::size(), and THROW_EXCEPTION.

◆ extractFeaturesSIFT()

void CFeatureExtraction::extractFeaturesSIFT	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Extract features from the image based on the SIFT method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.
ROI	(op. input) Region of Interest. Default: All the image.

Definition at line 77 of file CFeatureExtraction_SIFT.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), mrpt::vision::CFeatureList::end(), mrpt::utils::CImage::extract_patch(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::system::os::fclose(), mrpt::vision::featSIFT, mrpt::system::os::fopen(), mrpt::format(), mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), mrpt::system::launchProcess(), mrpt::math::MATRIX_FORMAT_FIXED, mrpt::system::os::memcpy(), MIN, mrpt::vision::CFeatureList::push_back(), mrpt::vision::CFeatureList::resize(), mrpt::utils::round(), mrpt::utils::CImage::saveToFile(), mrpt::vision::CFeatureList::saveToTextFile(), SIFT_DESCR_HIST_BINS, SIFT_DESCR_WIDTH, SIFT_IMG_DBL, SIFT_INTVLS, SIFT_SIGMA, mrpt::vision::CFeatureList::size(), mrpt::system::os::strcat(), mrpt::system::os::strcpy(), mrpt::utils::CImage::swap(), THROW_EXCEPTION, mrpt::vision::TImageROI::xMax, mrpt::vision::TImageROI::xMin, mrpt::vision::TImageROI::yMax, and mrpt::vision::TImageROI::yMin.

◆ extractFeaturesSURF()

void CFeatureExtraction::extractFeaturesSURF	(	const mrpt::utils::CImage &	img,
		CFeatureList &	feats,
		unsigned int	init_ID = `0`,
		unsigned int	nDesiredFeatures = `0`,
		const TImageROI &	ROI = `TImageROI()`
	)		const

private

Extract features from the image based on the SURF method.

Parameters

img	The image from where to extract the images.
feats	The list of extracted features.
nDesiredFeatures	Number of features to be extracted. Default: authomatic.

Definition at line 45 of file CFeatureExtraction_SURF.cpp.

References mrpt::vision::CFeatureList::clear(), mrpt::vision::CFeature::Create(), mrpt::utils::CImage::extract_patch(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::vision::featSURF, mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), min, mrpt::vision::CFeatureList::push_back(), mrpt::utils::round(), and THROW_EXCEPTION.

◆ getLaplacianValue()

double CFeatureExtraction::getLaplacianValue	(	void *	dog_pyr,
		int	octvs,
		int	intvls,
		float	row,
		float	col
	)		const

private

Computes the Laplacian value of the feature in the corresponing image in the pyramid.

Parameters

dog_pyr	Pyramid of images.
octvs	Number of considered octaves.
intvls	Number of intervales in octaves.
row	The row of the feature in the original image.
col	The column of the feature in the original image.

Definition at line 847 of file CFeatureExtraction_SIFT.cpp.

References detection_data::intvl, detection_data::octv, pixval32f(), and THROW_EXCEPTION.

◆ getTimesExtrema()

void CFeatureExtraction::getTimesExtrema	(	void *	dog_pyr,
		int	octvs,
		int	intvls,
		float	row,
		float	col,
		unsigned int &	nMin,
		unsigned int &	nMax
	)		const

private

Gets the number of times that a point in the image is higher or lower than the surroundings in the image-scale space.

Parameters

dog_pyr	Pyramid of images.
octvs	Number of considered octaves.
intvls	Number of intervales in octaves.
row	The row of the feature in the original image.
col	The column of the feature in the original image.
nMin	[out]: Times that the feature is lower than the surroundings.
nMax	[out]: Times that the feature is higher than the surroundings.

Definition at line 876 of file CFeatureExtraction_SIFT.cpp.

References detection_data::intvl, detection_data::octv, pixval32f(), THROW_EXCEPTION, and val.

◆ insertCvSeqInCFeatureList()

void CFeatureExtraction::insertCvSeqInCFeatureList	(	void *	features,
		CFeatureList &	list,
		unsigned int	init_ID = `0`
	)		const

private

Append a sequence of openCV features into an MRPT feature list.

Parameters

features	The sequence of features.
list	[in-out] The list of MRPT features.
init_ID	[in] The initial ID for the new features.

Definition at line 708 of file CFeatureExtraction_SIFT.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), feature::d, feature::descr, mrpt::vision::CFeatureList::end(), feature::ori, feature::scl, THROW_EXCEPTION, feature::x, and feature::y.

◆ internal_computeLogPolarImageDescriptors()

void CFeatureExtraction::internal_computeLogPolarImageDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute a log-polar image descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Note: Additional parameters from CFeatureExtraction::TOptions::LogPolarImagesOptions are used in this method.

Definition at line 27 of file CFeatureExtraction_logPolarImg.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), mrpt::vision::CFeatureList::end(), mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getChannelCount(), MRPT_END, MRPT_START, and THROW_EXCEPTION.

◆ internal_computeORBDescriptors()

void CFeatureExtraction::internal_computeORBDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute the ORB descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Definition at line 209 of file CFeatureExtraction_ORB.cpp.

References mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::utils::CImage::getAs(), mrpt::vision::CFeatureList::resize(), mrpt::vision::CFeatureList::size(), and THROW_EXCEPTION.

◆ internal_computePolarImageDescriptors()

void CFeatureExtraction::internal_computePolarImageDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute a polar-image descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Note: Additional parameters from CFeatureExtraction::TOptions::PolarImagesOptions are used in this method.

Definition at line 133 of file CFeatureExtraction_polarImg.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), mrpt::vision::CFeatureList::end(), mrpt::utils::CImage::getAs(), mrpt::utils::CImage::getChannelCount(), MRPT_END, MRPT_START, my_cvLinearPolar(), and THROW_EXCEPTION.

◆ internal_computeSiftDescriptors()

void CFeatureExtraction::internal_computeSiftDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute the SIFT descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Note: The SIFT descriptors for already located features can only be computed through the Hess and CSBinary implementations which may be specified in CFeatureExtraction::TOptions::SIFTOptions.

Definition at line 494 of file CFeatureExtraction_SIFT.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), mrpt::vision::CFeatureList::end(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::system::os::fclose(), mrpt::vision::featSIFT, mrpt::system::os::fopen(), mrpt::system::os::fprintf(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), mrpt::system::launchProcess(), MIN, MRPT_END, MRPT_START, mrpt::utils::CImage::saveToFile(), SIFT_DESCR_HIST_BINS, SIFT_DESCR_WIDTH, SIFT_IMG_DBL, SIFT_INTVLS, SIFT_SIGMA, mrpt::vision::CFeatureList::size(), mrpt::system::os::strcat(), mrpt::system::os::strcpy(), and THROW_EXCEPTION.

◆ internal_computeSpinImageDescriptors()

void CFeatureExtraction::internal_computeSpinImageDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute the intensity-domain spin images descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Note: Additional parameters from CFeatureExtraction::TOptions::SpinImagesOptions are used in this method.

Definition at line 25 of file CFeatureExtraction_spinImg.cpp.

References ASSERT_, mrpt::vision::CFeatureList::begin(), mrpt::utils::CImage::drawCircle(), mrpt::vision::CFeatureList::end(), mrpt::format(), mrpt::utils::CImage::get_unsafe(), mrpt::utils::CImage::getHeight(), mrpt::utils::CImage::getWidth(), mrpt::utils::CImage::isColor(), min, MRPT_END, MRPT_START, R, mrpt::utils::round(), mrpt::utils::CImage::saveToFile(), and mrpt::math::square().

◆ internal_computeSurfDescriptors()

void CFeatureExtraction::internal_computeSurfDescriptors	(	const mrpt::utils::CImage &	in_img,
		CFeatureList &	in_features
	)		const

private

Compute the SURF descriptor of the provided features into the input image.

Parameters

in_img	(input) The image from where to compute the descriptors.
in_features	(input/output) The list of features whose descriptors are going to be computed.

Definition at line 155 of file CFeatureExtraction_SURF.cpp.

References mrpt::vision::CFeatureList::begin(), mrpt::vision::CFeatureList::empty(), mrpt::vision::CFeatureList::end(), mrpt::utils::FAST_REF_OR_CONVERT_TO_GRAY, mrpt::utils::CImage::getAs(), mrpt::vision::CFeatureList::size(), and THROW_EXCEPTION.

◆ my_adjust_for_img_dbl()

void CFeatureExtraction::my_adjust_for_img_dbl ( void * features ) const

private

Adjust scale if the image was initially doubled.

Parameters

features The sequence of features.

Definition at line 745 of file CFeatureExtraction_SIFT.cpp.

References feature::scl, and THROW_EXCEPTION.

◆ my_scale_space_extrema()

void * CFeatureExtraction::my_scale_space_extrema	(	CFeatureList &	featList,
		void *	dog_pyr,
		int	octvs,
		int	intvls,
		double	contr_thr,
		int	curv_thr,
		void *	storage
	)		const

private

Computes extrema in the scale space.

Parameters

dog_pyr	Pyramid of images.
octvs	Number of considered octaves.
intvls	Number of intervales in octaves.

Definition at line 766 of file CFeatureExtraction_SIFT.cpp.

References mrpt::vision::CFeatureList::begin(), detection_data::c, mrpt::vision::CFeatureList::end(), feat_detection_data, feature::img_pt, detection_data::intvl, MRPT_UNUSED_PARAM, detection_data::octv, detection_data::r, SIFT_SIGMA, detection_data::subintvl, THROW_EXCEPTION, val, feature::x, and feature::y.

Member Data Documentation

◆ options

TOptions mrpt::vision::CFeatureExtraction::options

Set all the parameters of the desired method here before calling "detectFeatures".

Definition at line 198 of file CFeatureExtraction.h.

Referenced by mrpt::maps::CLandmarksMap::loadSiftFeaturesFromImageObservation(), and mrpt::slam::COccupancyGridMapFeatureExtractor::uncached_extractFeatures().

Detailed Description

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Private Member Functions

Member Enumeration Documentation

◆ TSIFTImplementation

Constructor & Destructor Documentation

◆ CFeatureExtraction()

◆ ~CFeatureExtraction()

Member Function Documentation

◆ computeDescriptors()

◆ convertCvSeqInCFeatureList()

◆ detectFeatures()

◆ extractFeaturesBCD()

◆ extractFeaturesFAST()

◆ extractFeaturesFASTER_N()

◆ extractFeaturesKLT()

◆ extractFeaturesORB()

◆ extractFeaturesSIFT()

◆ extractFeaturesSURF()

◆ getLaplacianValue()

◆ getTimesExtrema()

◆ insertCvSeqInCFeatureList()

◆ internal_computeLogPolarImageDescriptors()

◆ internal_computeORBDescriptors()

◆ internal_computePolarImageDescriptors()

◆ internal_computeSiftDescriptors()

◆ internal_computeSpinImageDescriptors()

◆ internal_computeSurfDescriptors()

◆ my_adjust_for_img_dbl()

◆ my_scale_space_extrema()

Member Data Documentation

◆ options