Visual Servoing Platform  version 3.3.0 under development (2020-02-17)
vpFeatureMomentAreaNormalized Class Reference

#include <visp3/visual_features/vpFeatureMomentAreaNormalized.h>

+ Inheritance diagram for vpFeatureMomentAreaNormalized:

Public Types

enum  { FEATURE_ALL = 0xffff }
 
enum  vpBasicFeatureDeallocatorType { user, vpServo }
 

Public Member Functions

 vpFeatureMomentAreaNormalized (vpMomentDatabase &data_base, double A_, double B_, double C_, vpFeatureMomentDatabase *featureMoments=NULL)
 
void compute_interaction ()
 
const char * momentName () const
 
const char * name () const
 
Inherited functionalities from vpFeatureMoment
vpBasicFeatureduplicate () const
 
void display (const vpCameraParameters &cam, const vpImage< unsigned char > &I, const vpColor &color=vpColor::green, unsigned int thickness=1) const
 
void display (const vpCameraParameters &cam, const vpImage< vpRGBa > &I, const vpColor &color=vpColor::green, unsigned int thickness=1) const
 
int getDimension (unsigned int select=FEATURE_ALL) const
 
void init (void)
 
vpMatrix interaction (unsigned int select=FEATURE_ALL)
 
void linkTo (vpFeatureMomentDatabase &featureMoments)
 
void print (unsigned int select=FEATURE_ALL) const
 
virtual void printDependencies (std::ostream &os) const
 
void update (double A, double B, double C)
 
Inherited functionalities from vpBasicFeature
unsigned int dimension_s ()
 
virtual vpColVector error (const vpBasicFeature &s_star, unsigned int select=FEATURE_ALL)
 
vpColVector get_s (unsigned int select=FEATURE_ALL) const
 
vpBasicFeatureDeallocatorType getDeallocate ()
 
virtual double operator[] (unsigned int i) const
 
void setDeallocate (vpBasicFeatureDeallocatorType d)
 
void setFlags ()
 

Static Public Member Functions

static unsigned int selectAll ()
 

Static Public Attributes

static const unsigned int FEATURE_LINE [32]
 

Protected Member Functions

const vpMomentgetMoment () const
 
void resetFlags ()
 

Protected Attributes

const vpMomentmoment
 
vpMomentDatabasemoments
 
vpFeatureMomentDatabasefeatureMomentsDataBase
 
std::vector< vpMatrixinteraction_matrices
 
double A
 
double B
 
double C
 
char _name [255]
 
vpColVector s
 
unsigned int dim_s
 
bool * flags
 
unsigned int nbParameters
 
vpBasicFeatureDeallocatorType deallocate
 

Detailed Description

Functionality computation for normalized surface moment feature. Computes the interaction matrix associated with vpMomentAreaNormalized.

The interaction matrix for the moment has the following form:

  • In the discrete case:

    \[ L_{a_n} = { \left[ \begin {array}{c} a_{{n}}Ae_{{2,0}}+a_{{n}}Be_{{1,1}} \\ \noalign{\medskip}a_{{n}}Ae_{{1,1}}+a_{{n}}Be_{{0,2}} \\ \noalign{\medskip}-a_{{n}}C+Bw_{{x}}-Aw_{{y}}\\ \noalign{\medskip}- \left( e_{{2,0}}+2\,e_{{0,2}} \right) y_{{g}}-e_{{2,1}}-x_{{g}}e_{{1, 1}}+\eta_{{1,1}}e_{{1,0}}-e_{{0,3}}+\eta_{{0,2}}e_{{0,1}} \\ \noalign{\medskip} \left( 2\,e_{{2,0}}+e_{{0,2}} \right) x_{{g}}+e_ {{3,0}}+y_{{g}}e_{{1,1}}-\eta_{{2,0}}e_{{1,0}}+e_{{1,2}}-\eta_{{1,1}}e _{{0,1}}\\ \noalign{\medskip}0\end {array} \right] }^t \]

  • In the dense case:

    \[ L_{a_n} = { \left[ \begin {array}{c} 1/2\,a_{{n}}A\\ \noalign{\medskip}1/2\,a_{{n }}B\\ \noalign{\medskip}-a_{{n}}C-3/2\,Ax_{{n}}-3/2\,By_{{n}} \\ \noalign{\medskip}-3/2\,y_{{n}}\\ \noalign{\medskip}3/2\,x_{{n}} \\ \noalign{\medskip}0\end {array} \right] }^t \]

    with:
    • $e_{i,j}=\frac{\mu_{i,j}}{NA}$
    • $NA=\mu_{2,0}+\mu_{0,2}$
    • $\eta$ is the centered and normalized moment. To do so, one must derive it and obtain a combination of interaction matrices by using (1). It allows to compute the interaction matrix for $ a_n $.

The interaction matrix computed is single-dimension (no selection possible) and can be obtained by calling vpFeatureMomentGravityCenterNormalized::interaction.

This feature is often used in moment-based visual servoing to control the depth parameter.

Minimum vpMomentObject order needed to compute this feature: 1 in dense mode and 3 in discrete mode.

This feature depends on:

Examples:
mbot-apriltag-ibvs.cpp, and servoBebop2.cpp.

Definition at line 178 of file vpFeatureMomentAreaNormalized.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum
inherited
Enumerator
FEATURE_ALL 

Definition at line 82 of file vpBasicFeature.h.

◆ vpBasicFeatureDeallocatorType

Indicates who should deallocate the feature.

Enumerator
user 
vpServo 

Definition at line 88 of file vpBasicFeature.h.

Constructor & Destructor Documentation

◆ vpFeatureMomentAreaNormalized()

vpFeatureMomentAreaNormalized::vpFeatureMomentAreaNormalized ( vpMomentDatabase data_base,
double  A_,
double  B_,
double  C_,
vpFeatureMomentDatabase featureMoments = NULL 
)
inline

Initializes the feature with information about the database of moment primitives, the object plane and feature database.

Parameters
data_base: Moment database. The database of moment primitives (first parameter) is mandatory. It is used to access different moment values later used to compute the final matrix.
A_: Plane coefficient in a $ A \times x+B \times y + C = \frac{1}{Z} $ plane.
B_: Plane coefficient in a $ A \times x+B \times y + C = \frac{1}{Z} $ plane.
C_: Plane coefficient in a $ A \times x+B \times y + C = \frac{1}{Z} $ plane.
featureMoments: Feature database.

Definition at line 193 of file vpFeatureMomentAreaNormalized.h.

References vpFeatureMoment::compute_interaction().

Member Function Documentation

◆ compute_interaction()

void vpFeatureMomentAreaNormalized::compute_interaction ( void  )
virtual

◆ dimension_s()

unsigned int vpBasicFeature::dimension_s ( )
inlineinherited

Return the dimension of the feature vector $\bf s$.

Definition at line 110 of file vpBasicFeature.h.

References vpColor::green.

◆ display() [1/2]

void vpFeatureMoment::display ( const vpCameraParameters cam,
const vpImage< unsigned char > &  I,
const vpColor color = vpColor::green,
unsigned int  thickness = 1 
) const
virtualinherited

Not implemented since visual representation of a moment doesn't often make sense.

Implements vpBasicFeature.

Definition at line 114 of file vpFeatureMoment.cpp.

◆ display() [2/2]

void vpFeatureMoment::display ( const vpCameraParameters cam,
const vpImage< vpRGBa > &  I,
const vpColor color = vpColor::green,
unsigned int  thickness = 1 
) const
virtualinherited

Not implemented since visual representation of a moment doesn't often make sense.

Implements vpBasicFeature.

Definition at line 128 of file vpFeatureMoment.cpp.

◆ duplicate()

vpBasicFeature * vpFeatureMoment::duplicate ( ) const
virtualinherited

Duplicates the feature into a vpGenericFeature harbouring the same properties. The resulting feature is of vpMomentGenericFeature type. While it still can compute interaction matrices and has acces to it's moment primitive, it has lost all precise information about its precise type and therefore cannot be used in a feature database.

Returns
The corresponding feature.

Implements vpBasicFeature.

Definition at line 220 of file vpFeatureMoment.cpp.

References vpFeatureMoment::A, vpFeatureMoment::B, vpFeatureMoment::C, vpBasicFeature::dim_s, vpFeatureMoment::featureMomentsDataBase, vpBasicFeature::flags, vpFeatureMoment::interaction_matrices, vpFeatureMoment::moment, vpFeatureMoment::moments, vpBasicFeature::nbParameters, vpColVector::resize(), and vpBasicFeature::s.

◆ error()

◆ get_s()

◆ getDeallocate()

vpBasicFeatureDeallocatorType vpBasicFeature::getDeallocate ( )
inlineinherited

Definition at line 123 of file vpBasicFeature.h.

◆ getDimension()

int vpFeatureMoment::getDimension ( unsigned int  select = FEATURE_ALL) const
inherited

Feature's dimension according to selection.

Definition at line 85 of file vpFeatureMoment.cpp.

References vpBasicFeature::dim_s, and vpBasicFeature::FEATURE_LINE.

◆ getMoment()

const vpMoment& vpFeatureMoment::getMoment ( ) const
inlineprotectedinherited

Definition at line 163 of file vpFeatureMoment.h.

◆ init()

void vpFeatureMoment::init ( void  )
virtualinherited

Initialize common parameters for moment features.

Implements vpBasicFeature.

Definition at line 56 of file vpFeatureMoment.cpp.

References vpBasicFeature::dim_s, vpBasicFeature::flags, vpMoment::get(), vpFeatureMoment::moment, vpBasicFeature::nbParameters, vpColVector::resize(), and vpBasicFeature::s.

◆ interaction()

vpMatrix vpFeatureMoment::interaction ( unsigned int  select = FEATURE_ALL)
virtualinherited

Retrieves the interaction matrix. No computation is done.

Parameters
select: Feature selector.
Returns
The corresponding interaction matrix.

There is no rule about the format of the feature selector. It may be different for different features. For example, for vpFeatureMomentBasic or vpFeatureMomentCentered features, select may refer to the $ (i,j) $ couple in the $ j \times order + i $ format, but for vpFeatureMomentCInvariant the selector allows to select couples $ (i,j,k,l...) $ in the following format: 1 << i

  • 1 << j + 1 << k + 1 << l.

Implements vpBasicFeature.

Definition at line 199 of file vpFeatureMoment.cpp.

References vpBasicFeature::dim_s, vpBasicFeature::FEATURE_LINE, vpFeatureMoment::interaction_matrices, and vpMatrix::stack().

Referenced by vpFeatureMomentCentered::compute_interaction().

◆ linkTo()

void vpFeatureMoment::linkTo ( vpFeatureMomentDatabase featureMoments)
inherited

Links the feature to the feature's database. NB: The feature's database is different from the moment's database.

Parameters
featureMoments: database in which the moment features are stored.

Definition at line 244 of file vpFeatureMoment.cpp.

References vpFeatureMoment::_name, vpFeatureMoment::featureMomentsDataBase, vpException::memoryAllocationError, and vpFeatureMoment::name().

Referenced by vpFeatureMomentCommon::vpFeatureMomentCommon().

◆ momentName()

const char* vpFeatureMomentAreaNormalized::momentName ( ) const
inlinevirtual

associated moment name

Implements vpFeatureMoment.

Definition at line 202 of file vpFeatureMomentAreaNormalized.h.

◆ name()

const char* vpFeatureMomentAreaNormalized::name ( ) const
inlinevirtual

feature name

Implements vpFeatureMoment.

Definition at line 206 of file vpFeatureMomentAreaNormalized.h.

◆ operator[]()

virtual double vpBasicFeature::operator[] ( unsigned int  i) const
inlinevirtualinherited

Return element i in the state vector (usage : x = s[i] )

Definition at line 130 of file vpBasicFeature.h.

◆ print()

void vpFeatureMoment::print ( unsigned int  select = FEATURE_ALL) const
virtualinherited

Outputs the content of the feature: it's corresponding selected moments.

Implements vpBasicFeature.

Definition at line 99 of file vpFeatureMoment.cpp.

References vpBasicFeature::dim_s, vpBasicFeature::FEATURE_LINE, and vpBasicFeature::s.

◆ printDependencies()

void vpFeatureMoment::printDependencies ( std::ostream &  os) const
virtualinherited

Interface function to display the moments and other interaction matrices on which a particular vpFeatureMoment is dependent upon Not made pure to maintain compatibility Recommended : Types inheriting from vpFeatureMoment should implement this function

Definition at line 281 of file vpFeatureMoment.cpp.

◆ resetFlags()

◆ selectAll()

static unsigned int vpBasicFeature::selectAll ( )
inlinestaticinherited

Select all the features.

Definition at line 142 of file vpBasicFeature.h.

◆ setDeallocate()

void vpBasicFeature::setDeallocate ( vpBasicFeatureDeallocatorType  d)
inlineinherited

Definition at line 137 of file vpBasicFeature.h.

Referenced by vpServo::addFeature().

◆ setFlags()

void vpBasicFeature::setFlags ( )
inherited

Set feature flags to true to prevent warning when re-computing the interaction matrix without having updated the feature.

Definition at line 141 of file vpBasicFeature.cpp.

References vpBasicFeature::flags, and vpBasicFeature::nbParameters.

◆ update()

void vpFeatureMoment::update ( double  A_,
double  B_,
double  C_ 
)
inherited

Updates the interaction matrices with the image plane the camera is facing. The plane must be in the format: $ \frac{1}{Z}=Ax+By+C $ . The moment primitives MUST be updated before calling this function.

This method also computes the interaction matrix. Therefore, you must call vpFeatureMoment::update before calling vpFeatureMoment::interaction.

Attention
The behaviour of this method is not the same as vpMoment::update which only acknowledges the new object. This method also computes the interaction matrices.
Parameters
A_: A coefficient of the plane.
B_: B coefficient of the plane.
C_: C coefficient of the plane.
Examples:
mbot-apriltag-ibvs.cpp, and servoBebop2.cpp.

Definition at line 153 of file vpFeatureMoment.cpp.

References vpFeatureMoment::A, vpFeatureMoment::B, vpFeatureMoment::C, vpFeatureMoment::compute_interaction(), vpBasicFeature::dim_s, vpBasicFeature::flags, vpMomentDatabase::get(), vpMoment::get(), vpFeatureMoment::moment, vpFeatureMoment::momentName(), vpFeatureMoment::moments, vpBasicFeature::nbParameters, vpException::notInitialized, vpColVector::resize(), and vpBasicFeature::s.

Referenced by vpFeatureMomentCommon::updateAll().

Member Data Documentation

◆ _name

char vpFeatureMoment::_name[255]
protectedinherited

Definition at line 171 of file vpFeatureMoment.h.

Referenced by vpFeatureMoment::linkTo().

◆ A

◆ B

◆ C

◆ deallocate

◆ dim_s

◆ FEATURE_LINE

const unsigned int vpBasicFeature::FEATURE_LINE
staticinherited
Initial value:
= {
(unsigned int)(1 << 0), (unsigned int)(1 << 1), (unsigned int)(1 << 2), (unsigned int)(1 << 3),
(unsigned int)(1 << 4), (unsigned int)(1 << 5), (unsigned int)(1 << 6), (unsigned int)(1 << 7),
(unsigned int)(1 << 8), (unsigned int)(1 << 9), (unsigned int)(1 << 10), (unsigned int)(1 << 11),
(unsigned int)(1 << 12), (unsigned int)(1 << 13), (unsigned int)(1 << 14), (unsigned int)(1 << 15),
(unsigned int)(1 << 16), (unsigned int)(1 << 17), (unsigned int)(1 << 18), (unsigned int)(1 << 19),
(unsigned int)(1 << 20), (unsigned int)(1 << 21), (unsigned int)(1 << 22), (unsigned int)(1 << 23),
(unsigned int)(1 << 24), (unsigned int)(1 << 25), (unsigned int)(1 << 26), (unsigned int)(1 << 27),
(unsigned int)(1 << 28), (unsigned int)(1 << 29), (unsigned int)(1 << 30), (unsigned int)(1 << 31)}

Definition at line 80 of file vpBasicFeature.h.

Referenced by vpBasicFeature::error(), vpGenericFeature::error(), vpBasicFeature::get_s(), vpBasicFeature::getDimension(), vpFeatureMoment::getDimension(), vpGenericFeature::interaction(), vpFeatureMoment::interaction(), vpGenericFeature::print(), vpFeatureMoment::print(), vpFeatureVanishingPoint::selectAlpha(), vpFeatureSegment::selectAlpha(), vpFeatureVanishingPoint::selectAtanOneOverRho(), vpFeatureSegment::selectL(), vpFeatureEllipse::selectMu02(), vpFeatureEllipse::selectMu11(), vpFeatureEllipse::selectMu20(), vpFeatureVanishingPoint::selectOneOverRho(), vpFeatureLine::selectRho(), vpFeaturePointPolar::selectRho(), vpFeatureLine::selectTheta(), vpFeaturePointPolar::selectTheta(), vpFeatureThetaU::selectTUx(), vpFeatureThetaU::selectTUy(), vpFeatureThetaU::selectTUz(), vpFeatureTranslation::selectTx(), vpFeatureTranslation::selectTy(), vpFeatureTranslation::selectTz(), vpFeatureVanishingPoint::selectX(), vpFeatureEllipse::selectX(), vpFeaturePoint::selectX(), vpFeaturePoint3D::selectX(), vpFeatureSegment::selectXc(), vpFeatureVanishingPoint::selectY(), vpFeatureEllipse::selectY(), vpFeaturePoint::selectY(), vpFeaturePoint3D::selectY(), vpFeatureSegment::selectYc(), and vpFeaturePoint3D::selectZ().

◆ featureMomentsDataBase

◆ flags

bool* vpBasicFeature::flags
protectedinherited

Ensure that all the parameters needed to compute the iteraction matrix are set.

Definition at line 98 of file vpBasicFeature.h.

Referenced by vpFeatureEllipse::buildFrom(), vpFeatureDepth::buildFrom(), vpFeaturePoint::buildFrom(), vpFeatureLine::buildFrom(), vpFeaturePoint3D::buildFrom(), vpFeatureThetaU::buildFrom(), vpFeaturePointPolar::buildFrom(), vpFeatureTranslation::buildFrom(), vpFeatureMoment::duplicate(), vpFeatureEllipse::init(), vpFeatureVanishingPoint::init(), vpFeatureLuminance::init(), vpFeatureSegment::init(), vpFeatureDepth::init(), vpFeaturePoint::init(), vpFeatureMoment::init(), vpFeatureLine::init(), vpFeaturePoint3D::init(), vpFeatureThetaU::init(), vpFeaturePointPolar::init(), vpFeatureTranslation::init(), vpFeatureVanishingPoint::interaction(), vpFeatureEllipse::interaction(), vpFeatureSegment::interaction(), vpFeatureDepth::interaction(), vpFeaturePoint::interaction(), vpFeatureLine::interaction(), vpFeaturePoint3D::interaction(), vpFeatureThetaU::interaction(), vpFeaturePointPolar::interaction(), vpFeatureTranslation::interaction(), vpBasicFeature::operator=(), vpBasicFeature::resetFlags(), vpFeaturePointPolar::set_rho(), vpFeaturePointPolar::set_rhoThetaZ(), vpFeaturePointPolar::set_theta(), vpFeatureThetaU::set_TUx(), vpFeatureThetaU::set_TUy(), vpFeatureThetaU::set_TUz(), vpFeatureVanishingPoint::set_x(), vpFeatureEllipse::set_x(), vpFeatureDepth::set_x(), vpFeaturePoint::set_x(), vpFeaturePoint3D::set_X(), vpFeatureEllipse::set_xy(), vpFeaturePoint::set_xyZ(), vpFeaturePoint3D::set_XYZ(), vpFeatureDepth::set_xyZLogZoverZstar(), vpFeatureVanishingPoint::set_y(), vpFeatureEllipse::set_y(), vpFeatureDepth::set_y(), vpFeaturePoint::set_y(), vpFeaturePoint3D::set_Y(), vpFeatureLuminance::set_Z(), vpFeatureDepth::set_Z(), vpFeaturePoint::set_Z(), vpFeaturePoint3D::set_Z(), vpFeaturePointPolar::set_Z(), vpFeatureEllipse::setABC(), vpFeatureLine::setABCD(), vpFeatureVanishingPoint::setAlpha(), vpFeatureVanishingPoint::setAtanOneOverRho(), vpBasicFeature::setFlags(), vpFeatureEllipse::setMu(), vpFeatureVanishingPoint::setOneOverRho(), vpFeatureLine::setRhoTheta(), vpFeatureMoment::update(), vpFeatureLuminance::vpFeatureLuminance(), and vpBasicFeature::~vpBasicFeature().

◆ interaction_matrices

◆ moment

◆ moments

◆ nbParameters

◆ s

vpColVector vpBasicFeature::s
protectedinherited

State of the visual feature.

Definition at line 92 of file vpBasicFeature.h.

Referenced by vpFeatureEllipse::buildFrom(), vpFeatureLuminance::buildFrom(), vpFeatureDepth::buildFrom(), vpFeaturePoint::buildFrom(), vpFeatureLine::buildFrom(), vpFeaturePoint3D::buildFrom(), vpFeatureThetaU::buildFrom(), vpFeaturePointPolar::buildFrom(), vpFeatureTranslation::buildFrom(), vpFeatureEllipse::display(), vpFeatureMoment::duplicate(), vpFeatureEllipse::error(), vpFeatureVanishingPoint::error(), vpFeatureLuminance::error(), vpBasicFeature::error(), vpFeatureMomentAlpha::error(), vpFeatureDepth::error(), vpGenericFeature::error(), vpFeaturePoint::error(), vpFeatureLine::error(), vpFeaturePoint3D::error(), vpFeatureThetaU::error(), vpFeaturePointPolar::error(), vpFeatureTranslation::error(), vpFeatureDepth::get_LogZoverZstar(), vpFeaturePointPolar::get_rho(), vpBasicFeature::get_s(), vpGenericFeature::get_s(), vpFeaturePointPolar::get_theta(), vpFeatureThetaU::get_TUx(), vpFeatureThetaU::get_TUy(), vpFeatureThetaU::get_TUz(), vpFeatureTranslation::get_Tx(), vpFeatureTranslation::get_Ty(), vpFeatureTranslation::get_Tz(), vpFeatureVanishingPoint::get_x(), vpFeaturePoint::get_x(), vpFeaturePoint3D::get_X(), vpFeatureVanishingPoint::get_y(), vpFeaturePoint::get_y(), vpFeaturePoint3D::get_Y(), vpFeaturePoint3D::get_Z(), vpFeatureVanishingPoint::getAlpha(), vpFeatureVanishingPoint::getAtanOneOverRho(), vpBasicFeature::getDimension(), vpFeatureVanishingPoint::getOneOverRho(), vpFeatureVanishingPoint::init(), vpFeatureEllipse::init(), vpFeatureLuminance::init(), vpFeatureSegment::init(), vpFeatureDepth::init(), vpGenericFeature::init(), vpFeaturePoint::init(), vpFeatureMoment::init(), vpFeatureLine::init(), vpFeaturePoint3D::init(), vpFeatureThetaU::init(), vpFeaturePointPolar::init(), vpFeatureTranslation::init(), vpFeatureEllipse::interaction(), vpFeatureLine::interaction(), vpFeatureThetaU::interaction(), vpFeatureTranslation::interaction(), vpBasicFeature::operator=(), vpFeatureEllipse::print(), vpFeatureSegment::print(), vpGenericFeature::print(), vpFeatureMoment::print(), vpFeatureLine::print(), vpFeatureThetaU::print(), vpFeatureTranslation::print(), vpFeatureDepth::set_LogZoverZstar(), vpFeaturePointPolar::set_rho(), vpGenericFeature::set_s(), vpFeaturePointPolar::set_theta(), vpFeatureThetaU::set_TUx(), vpFeatureThetaU::set_TUy(), vpFeatureThetaU::set_TUz(), vpFeatureTranslation::set_Tx(), vpFeatureTranslation::set_Ty(), vpFeatureTranslation::set_Tz(), vpFeatureVanishingPoint::set_x(), vpFeatureEllipse::set_x(), vpFeaturePoint::set_x(), vpFeaturePoint3D::set_X(), vpFeatureEllipse::set_xy(), vpFeatureVanishingPoint::set_y(), vpFeatureEllipse::set_y(), vpFeaturePoint::set_y(), vpFeaturePoint3D::set_Y(), vpFeaturePoint3D::set_Z(), vpFeatureVanishingPoint::setAlpha(), vpFeatureVanishingPoint::setAtanOneOverRho(), vpFeatureEllipse::setMu(), vpFeatureVanishingPoint::setOneOverRho(), vpFeatureLine::setRhoTheta(), vpFeatureMoment::update(), and vpGenericFeature::vpGenericFeature().