Main class for marker detection. More...

#include <markerdetector.h>

Classes
class	MarkerCandidate

struct	Params

Public Types
enum	CornerRefinementMethod { NONE, SUBPIX, LINES }

enum	ThresholdMethods { FIXED_THRES, ADPT_THRES, CANNY }

Public Member Functions
void	adpt_threshold_multi (const cv::Mat &grey, std::vector< cv::Mat > &out, double param1, double param1_range, double param2, double param2_range=0)

std::vector< aruco::Marker >	detect (const cv::Mat &input) throw (cv::Exception)

std::vector< aruco::Marker >	detect (const cv::Mat &input, const CameraParameters &camParams, float markerSizeMeters, bool setYPerperdicular=false) throw (cv::Exception)

void	detect (const cv::Mat &input, std::vector< Marker > &detectedMarkers, CameraParameters camParams, float markerSizeMeters=-1, bool setYPerperdicular=false) throw (cv::Exception)

void	detect (const cv::Mat &input, std::vector< Marker > &detectedMarkers, cv::Mat camMatrix=cv::Mat(), cv::Mat distCoeff=cv::Mat(), float markerSizeMeters=-1, bool setYPerperdicular=false) throw (cv::Exception)

void	detectRectangles (const cv::Mat &thresImg, vector< std::vector< cv::Point2f > > &candidates)

const vector< std::vector< cv::Point2f > > &	getCandidates ()

CornerRefinementMethod	getCornerRefinementMethod () const

int	getDesiredSpeed () const

cv::Ptr< MarkerLabeler >	getMarkerLabeler () throw (cv::Exception)

void	getMinMaxSize (float &min, float &max)

Params	getParams () const

const cv::Mat &	getThresholdedImage ()

ThresholdMethods	getThresholdMethod () const

void	getThresholdParams (double &param1, double &param2) const

int	getWarpSize () const

	MarkerDetector ()

void	refineCandidateLines (MarkerCandidate &candidate, const cv::Mat &camMatrix, const cv::Mat &distCoeff)

void	setCornerRefinementMethod (CornerRefinementMethod method, int val=-1)

void	setDesiredSpeed (int val)

void	setDictionary (std::string dict_type, float error_correction_rate=0) throw (cv::Exception)

void	setDictionary (Dictionary::DICT_TYPES dict_type, float error_correction_rate=0) throw (cv::Exception)
	setDictionary Specifies the dictionary you want to use for marker decoding More...

void	setMarkerLabeler (cv::Ptr< MarkerLabeler > detector) throw (cv::Exception)
	setMakerLabeler sets the labeler employed to analyze the squares and extract the inner binary code More...

void	setMinMaxSize (float min=0.03, float max=0.5) throw (cv::Exception)

void	setParams (Params p)

void	setThresholdMethod (ThresholdMethods m)

void	setThresholdParamRange (size_t r1=0, size_t r2=0)

void	setThresholdParams (double param1, double param2)

void	setWarpSize (int val) throw (cv::Exception)

void	thresHold (int method, const cv::Mat &grey, cv::Mat &thresImg, double param1=-1, double param2=-1) throw (cv::Exception)

bool	warp (cv::Mat &in, cv::Mat &out, cv::Size size, std::vector< cv::Point2f > points) throw (cv::Exception)

	~MarkerDetector ()

Private Member Functions
void	detectRectangles (vector< cv::Mat > &vimages, vector< MarkerCandidate > &candidates)

void	distortPoints (vector< cv::Point2f > in, vector< cv::Point2f > &out, const cv::Mat &camMatrix, const cv::Mat &distCoeff)

void	draw (cv::Mat out, const std::vector< Marker > &markers)

void	drawAllContours (cv::Mat input, std::vector< std::vector< cv::Point > > &contours)

void	drawApproxCurve (cv::Mat &in, std::vector< cv::Point > &approxCurve, cv::Scalar color)

void	drawContour (cv::Mat &in, std::vector< cv::Point > &contour, cv::Scalar)

void	findCornerMaxima (vector< cv::Point2f > &Corners, const cv::Mat &grey, int wsize)

cv::Point2f	getCrossPoint (const cv::Point3f &line1, const cv::Point3f &line2)

void	interpolate2Dline (const vector< cv::Point2f > &inPoints, cv::Point3f &outLine)

bool	isInto (cv::Mat &contour, std::vector< cv::Point2f > &b)

template<typename T >
void	joinVectors (vector< vector< T > > &vv, vector< T > &v, bool clearv=false)

int	perimeter (std::vector< cv::Point2f > &a)

template<typename T >
void	removeElements (vector< T > &vinout, const vector< bool > &toRemove)

bool	warp_cylinder (cv::Mat &in, cv::Mat &out, cv::Size size, MarkerCandidate &mc) throw (cv::Exception)

Private Attributes
vector< std::vector< cv::Point2f > >	_candidates

Params	_params

cv::Mat	grey

vector< cv::Mat >	imagePyramid

cv::Ptr< MarkerLabeler >	markerIdDetector

cv::Mat	thres

Detailed Description

Main class for marker detection.

Definition at line 44 of file markerdetector.h.

Member Enumeration Documentation

◆ CornerRefinementMethod

enum aruco::MarkerDetector::CornerRefinementMethod

Methods for corner refinement

Enumerator
NONE
SUBPIX
LINES

Definition at line 50 of file markerdetector.h.

◆ ThresholdMethods

enum aruco::MarkerDetector::ThresholdMethods

This set the type of thresholding methods available

Enumerator
FIXED_THRES
ADPT_THRES
CANNY

Definition at line 55 of file markerdetector.h.

Constructor & Destructor Documentation

◆ MarkerDetector()

aruco::MarkerDetector::MarkerDetector ( )

See

Definition at line 50 of file markerdetector.cpp.

◆ ~MarkerDetector()

aruco::MarkerDetector::~MarkerDetector ( )

Definition at line 66 of file markerdetector.cpp.

Member Function Documentation

◆ adpt_threshold_multi()

void aruco::MarkerDetector::adpt_threshold_multi	(	const cv::Mat &	grey,
		std::vector< cv::Mat > &	out,
		double	param1,
		double	param1_range,
		double	param2,
		double	param2_range = `0`
	)

A

Definition at line 477 of file markerdetector.cpp.

◆ detect() [1/4]

std::vector< aruco::Marker > aruco::MarkerDetector::detect	(	const cv::Mat &	input	)
throw	(	cv::Exception
	)

Detects the markers in the image passed

If you provide information about the camera parameters and the size of the marker, then, the extrinsics of the markers are detected

Parameters

input	input color image
camMatrix	intrinsic camera information.
distCoeff	camera distorsion coefficient. If set Mat() if is assumed no camera distorion
markerSizeMeters	size of the marker sides expressed in meters. If not specified this value, the extrinsics of the markers are not detected.
setYPerperdicular	If set the Y axis will be perpendicular to the surface. Otherwise, it will be the Z axis

Returns: vector with the detected markers

Definition at line 77 of file markerdetector.cpp.

◆ detect() [2/4]

std::vector< aruco::Marker > aruco::MarkerDetector::detect	(	const cv::Mat &	input,
		const CameraParameters &	camParams,
		float	markerSizeMeters,
		bool	setYPerperdicular = `false`
	)
throw	(	cv::Exception
	)

Definition at line 83 of file markerdetector.cpp.

◆ detect() [3/4]

void aruco::MarkerDetector::detect	(	const cv::Mat &	input,
		std::vector< Marker > &	detectedMarkers,
		CameraParameters	camParams,
		float	markerSizeMeters = `-1`,
		bool	setYPerperdicular = `false`
	)
throw	(	cv::Exception
	)

Detects the markers in the image passed

If you provide information about the camera parameters and the size of the marker, then, the extrinsics of the markers are detected

Parameters

input	input color image
detectedMarkers	output vector with the markers detected
camParams	Camera parameters
markerSizeMeters	size of the marker sides expressed in meters
setYPerperdicular	If set the Y axis will be perpendicular to the surface. Otherwise, it will be the Z axis

Definition at line 96 of file markerdetector.cpp.

◆ detect() [4/4]

void aruco::MarkerDetector::detect	(	const cv::Mat &	input,
		std::vector< Marker > &	detectedMarkers,
		cv::Mat	camMatrix = `cv::Mat()`,
		cv::Mat	distCoeff = `cv::Mat()`,
		float	markerSizeMeters = `-1`,
		bool	setYPerperdicular = `false`
	)
throw	(	cv::Exception
	)

Detects the markers in the image passed

If you provide information about the camera parameters and the size of the marker, then, the extrinsics of the markers are detected

NOTE: be sure that the camera matrix is for this image size. If you do not know what I am talking about, use functions above and not this one

Parameters

input	input color image
detectedMarkers	output vector with the markers detected
camMatrix	intrinsic camera information.
distCoeff	camera distorsion coefficient. If set Mat() if is assumed no camera distorion
markerSizeMeters	size of the marker sides expressed in meters
setYPerperdicular	If set the Y axis will be perpendicular to the surface. Otherwise, it will be the Z axis

◆ detectRectangles() [1/2]

void aruco::MarkerDetector::detectRectangles	(	const cv::Mat &	thresImg,
		vector< std::vector< cv::Point2f > > &	candidates
	)

Detection of candidates to be markers, i.e., rectangles. This function returns in candidates all the rectangles found in a thresolded image

◆ detectRectangles() [2/2]

void aruco::MarkerDetector::detectRectangles	(	vector< cv::Mat > &	vimages,
		vector< MarkerCandidate > &	candidates
	)

private

Detection of candidates to be markers, i.e., rectangles. This function returns in candidates all the rectangles found in a thresolded image

for each contour, analyze if it is a paralelepiped likely to be the marker

sort the points in anti-clockwise order

remove these elements which corners are too close to each other

Definition at line 328 of file markerdetector.cpp.

◆ distortPoints()

void aruco::MarkerDetector::distortPoints	(	vector< cv::Point2f >	in,
		vector< cv::Point2f > &	out,
		const cv::Mat &	camMatrix,
		const cv::Mat &	distCoeff
	)

private

Definition at line 1017 of file markerdetector.cpp.

◆ draw()

void aruco::MarkerDetector::draw	(	cv::Mat	out,
		const std::vector< Marker > &	markers
	)

private

Definition at line 1064 of file markerdetector.cpp.

◆ drawAllContours()

void aruco::MarkerDetector::drawAllContours	(	cv::Mat	input,
		std::vector< std::vector< cv::Point > > &	contours
	)

private

Definition at line 1038 of file markerdetector.cpp.

◆ drawApproxCurve()

void aruco::MarkerDetector::drawApproxCurve	(	cv::Mat &	in,
		std::vector< cv::Point > &	approxCurve,
		cv::Scalar	color
	)

private

Definition at line 1052 of file markerdetector.cpp.

◆ drawContour()

void aruco::MarkerDetector::drawContour	(	cv::Mat &	in,
		std::vector< cv::Point > &	contour,
		cv::Scalar
	)

private

Definition at line 1046 of file markerdetector.cpp.

◆ findCornerMaxima()

void aruco::MarkerDetector::findCornerMaxima	(	vector< cv::Point2f > &	Corners,
		const cv::Mat &	grey,
		int	wsize
	)

private

Definition at line 1099 of file markerdetector.cpp.

◆ getCandidates()

const vector< std::vector< cv::Point2f > >& aruco::MarkerDetector::getCandidates ( )

inline

Returns a list candidates to be markers (rectangles), for which no valid id was found after calling detectRectangles

Definition at line 337 of file markerdetector.h.

◆ getCornerRefinementMethod()

CornerRefinementMethod aruco::MarkerDetector::getCornerRefinementMethod ( ) const

inline

Deprecated:

Definition at line 234 of file markerdetector.h.

◆ getCrossPoint()

Point2f aruco::MarkerDetector::getCrossPoint	(	const cv::Point3f &	line1,
		const cv::Point3f &	line2
	)

private

Definition at line 994 of file markerdetector.cpp.

◆ getDesiredSpeed()

int aruco::MarkerDetector::getDesiredSpeed ( ) const

inline

Deprecated:

Definition at line 270 of file markerdetector.h.

◆ getMarkerLabeler()

cv::Ptr<MarkerLabeler> aruco::MarkerDetector::getMarkerLabeler	(		)
throw	(	cv::Exception
	)

inline

Definition at line 301 of file markerdetector.h.

◆ getMinMaxSize()

void aruco::MarkerDetector::getMinMaxSize	(	float &	min,
		float &	max
	)

inline

Deprecated:: use setParams() and getParams() reads the min and max sizes employed

Parameters

min	output size of the contour to consider a possible marker as valid (0,1]
max	output size of the contour to consider a possible marker as valid [0,1)

Definition at line 258 of file markerdetector.h.

◆ getParams()

Params aruco::MarkerDetector::getParams ( ) const

inline

Returns operating params

Definition at line 155 of file markerdetector.h.

◆ getThresholdedImage()

const cv::Mat& aruco::MarkerDetector::getThresholdedImage ( )

inline

Returns a reference to the internal image thresholded. It is for visualization purposes and to adjust manually the parameters

Definition at line 182 of file markerdetector.h.

◆ getThresholdMethod()

ThresholdMethods aruco::MarkerDetector::getThresholdMethod ( ) const

inline

Returns the current threshold method

Definition at line 193 of file markerdetector.h.

◆ getThresholdParams()

void aruco::MarkerDetector::getThresholdParams	(	double &	param1,
		double &	param2
	)		const

inline

Deprecated:: use setParams() and getParams() Set the parameters of the threshold method We are currently using the Adptive threshold ee opencv doc of adaptiveThreshold for more info param1: blockSize of the pixel neighborhood that is used to calculate a threshold value for the pixel param2: The constant subtracted from the mean or weighted mean

Definition at line 220 of file markerdetector.h.

◆ getWarpSize()

int aruco::MarkerDetector::getWarpSize ( ) const

inline

Deprecated:: use setParams() and getParams()

Definition at line 283 of file markerdetector.h.

◆ interpolate2Dline()

void aruco::MarkerDetector::interpolate2Dline	(	const vector< cv::Point2f > &	inPoints,
		cv::Point3f &	outLine
	)

private

Definition at line 940 of file markerdetector.cpp.

◆ isInto()

bool aruco::MarkerDetector::isInto	(	cv::Mat &	contour,
		std::vector< cv::Point2f > &	b
	)

private

Definition at line 831 of file markerdetector.cpp.

◆ joinVectors()

template<typename T >

void aruco::MarkerDetector::joinVectors	(	vector< vector< T > > &	vv,
		vector< T > &	v,
		bool	clearv = `false`
	)

inlineprivate

Definition at line 417 of file markerdetector.h.

◆ perimeter()

int aruco::MarkerDetector::perimeter ( std::vector< cv::Point2f > & a )

private

Definition at line 844 of file markerdetector.cpp.

◆ refineCandidateLines()

void aruco::MarkerDetector::refineCandidateLines	(	MarkerDetector::MarkerCandidate &	candidate,
		const cv::Mat &	camMatrix,
		const cv::Mat &	distCoeff
	)

Refine MarkerCandidate Corner using LINES method

Parameters

candidate candidate to refine corners

Definition at line 861 of file markerdetector.cpp.

◆ removeElements()

template<typename T >

void aruco::MarkerDetector::removeElements	(	vector< T > &	vinout,
		const vector< bool > &	toRemove
	)

inlineprivate

Given a vector vinout with elements and a boolean vector indicating the lements from it to remove, this function remove the elements

Parameters

vinout
toRemove

Definition at line 393 of file markerdetector.h.

◆ setCornerRefinementMethod()

void aruco::MarkerDetector::setCornerRefinementMethod	(	CornerRefinementMethod	method,
		int	val = `-1`
	)

inline

Deprecated:: use setParams() and getParams() Sets the method for corner refinement When using SUBPIX, the second value indicates the window size in which search is done. Default value is 5

Definition at line 231 of file markerdetector.h.

◆ setDesiredSpeed()

void aruco::MarkerDetector::setDesiredSpeed ( int val )

inline

Deprecated:: Is now null

Definition at line 267 of file markerdetector.h.

◆ setDictionary() [1/2]

void aruco::MarkerDetector::setDictionary	(	std::string	dict_type,
		float	error_correction_rate = `0`
	)
throw	(	cv::Exception
	)

Sets the dictionary to be employed. You can choose:ARUCO,//original aruco dictionary. By default ARUCO_MIP_25h7, ARUCO_MIP_16h3, ARUCO_MIP_36h12, **** recommended ARTAG,// ARTOOLKITPLUS, ARTOOLKITPLUSBCH,// TAG16h5,TAG25h7,TAG25h9,TAG36h11,TAG36h10//APRIL TAGS DICIONARIES

◆ setDictionary() [2/2]

void aruco::MarkerDetector::setDictionary	(	Dictionary::DICT_TYPES	dict_type,
		float	error_correction_rate = `0`
	)
throw	(	cv::Exception
	)

setDictionary Specifies the dictionary you want to use for marker decoding

Parameters

dict_type dictionary employed for decoding markers

See also: Dictionary

Parameters

error_correction_rate value indicating the correction error allowed. Is in range [0,1]. 0 means no correction at all. So an erroneous bit will result in discarding the marker. 1, mean full correction. The maximum number of bits that can be corrected depends on each ditionary. We recommend using values from 0 to 0.5. (in general, this will allow up to 3 bits or correction).

Definition at line 1151 of file markerdetector.cpp.

◆ setMarkerLabeler()

void aruco::MarkerDetector::setMarkerLabeler	(	cv::Ptr< MarkerLabeler >	detector	)
throw	(	cv::Exception
	)

setMakerLabeler sets the labeler employed to analyze the squares and extract the inner binary code

Methods you may not need

Thesde methods do the hard work. They have been set public in case you want to do customizations

Parameters

detector

Definition at line 1145 of file markerdetector.cpp.

◆ setMinMaxSize()

void aruco::MarkerDetector::setMinMaxSize	(	float	min = `0.03`,
		float	max = `0.5`
	)
throw	(	cv::Exception
	)

inline

Deprecated:: use setParams() and getParams() Specifies the min and max sizes of the markers as a fraction of the image size. By size we mean the maximum of cols and rows.

Parameters

min	size of the contour to consider a possible marker as valid (0,1]
max	size of the contour to consider a possible marker as valid [0,1)

Definition at line 243 of file markerdetector.h.

◆ setParams()

void aruco::MarkerDetector::setParams ( Params p )

inline

Sets operating params

Definition at line 152 of file markerdetector.h.

◆ setThresholdMethod()

void aruco::MarkerDetector::setThresholdMethod ( ThresholdMethods m )

inline

Deprecated:: use setParams() and getParams() Sets the threshold method

Definition at line 190 of file markerdetector.h.

◆ setThresholdParamRange()

void aruco::MarkerDetector::setThresholdParamRange	(	size_t	r1 = `0`,
		size_t	r2 = `0`
	)

inline

Deprecated:: use setParams() and getParams() Allows for a parallel search of several values of the param1 simultaneously (in different threads) The param r1 the indicates how many values around the current value of param1 are evaluated. In other words if r1>0, param1 is searched in range [param1- r1 ,param1+ r1 ]

r2 unused yet. Added in case of future need.

Definition at line 212 of file markerdetector.h.

◆ setThresholdParams()

void aruco::MarkerDetector::setThresholdParams	(	double	param1,
		double	param2
	)

inline

Deprecated:: use setParams() and getParams() Set the parameters of the threshold method We are currently using the Adptive threshold ee opencv doc of adaptiveThreshold for more info

Parameters

param1	blockSize of the pixel neighborhood that is used to calculate a threshold value for the pixel
param2	The constant subtracted from the mean or weighted mean

Definition at line 200 of file markerdetector.h.

◆ setWarpSize()

void aruco::MarkerDetector::setWarpSize	(	int	val	)
throw	(	cv::Exception
	)

inline

Deprecated:: use setParams() and getParams() Specifies the size for the canonical marker image. A big value makes the detection slower than a small value. Minimun value is 10. Default value is 56.

Definition at line 276 of file markerdetector.h.

◆ thresHold()

void aruco::MarkerDetector::thresHold	(	int	method,
		const cv::Mat &	grey,
		cv::Mat &	thresImg,
		double	param1 = `-1`,
		double	param2 = `-1`
	)
throw	(	cv::Exception
	)

Thesholds the passed image with the specified method.

Definition at line 526 of file markerdetector.cpp.

◆ warp()

bool aruco::MarkerDetector::warp	(	cv::Mat &	in,
		cv::Mat &	out,
		cv::Size	size,
		std::vector< cv::Point2f >	points
	)
throw	(	cv::Exception
	)

Given the iput image with markers, creates an output image with it in the canonical position

Parameters

in	input image
out	image with the marker
size	of out
points	4 corners of the marker in the image in

Returns: true if the operation succeed

Definition at line 568 of file markerdetector.cpp.

◆ warp_cylinder()

bool aruco::MarkerDetector::warp_cylinder	(	cv::Mat &	in,
		cv::Mat &	out,
		cv::Size	size,
		MarkerCandidate &	mc
	)
throw	(	cv::Exception
	)

private

Definition at line 683 of file markerdetector.cpp.

Member Data Documentation

◆ _candidates

vector< std::vector< cv::Point2f > > aruco::MarkerDetector::_candidates

private

Definition at line 369 of file markerdetector.h.

◆ _params

Params aruco::MarkerDetector::_params

private

Definition at line 367 of file markerdetector.h.

◆ grey

cv::Mat aruco::MarkerDetector::grey

private

Definition at line 371 of file markerdetector.h.

◆ imagePyramid

vector<cv::Mat > aruco::MarkerDetector::imagePyramid

private

Definition at line 425 of file markerdetector.h.

◆ markerIdDetector

cv::Ptr<MarkerLabeler> aruco::MarkerDetector::markerIdDetector

private

Definition at line 373 of file markerdetector.h.

◆ thres

cv::Mat aruco::MarkerDetector::thres

private

Definition at line 371 of file markerdetector.h.

The documentation for this class was generated from the following files:

Classes

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ CornerRefinementMethod

◆ ThresholdMethods

Constructor & Destructor Documentation

◆ MarkerDetector()

◆ ~MarkerDetector()

Member Function Documentation

◆ adpt_threshold_multi()

◆ detect() [1/4]

◆ detect() [2/4]

◆ detect() [3/4]

◆ detect() [4/4]

◆ detectRectangles() [1/2]

◆ detectRectangles() [2/2]

◆ distortPoints()

◆ draw()

◆ drawAllContours()

◆ drawApproxCurve()

◆ drawContour()

◆ findCornerMaxima()

◆ getCandidates()

◆ getCornerRefinementMethod()

◆ getCrossPoint()

◆ getDesiredSpeed()

◆ getMarkerLabeler()

◆ getMinMaxSize()

◆ getParams()

◆ getThresholdedImage()

◆ getThresholdMethod()

◆ getThresholdParams()

◆ getWarpSize()

◆ interpolate2Dline()

◆ isInto()

◆ joinVectors()

◆ perimeter()

◆ refineCandidateLines()

◆ removeElements()

◆ setCornerRefinementMethod()

◆ setDesiredSpeed()

◆ setDictionary() [1/2]

◆ setDictionary() [2/2]

◆ setMarkerLabeler()

Thesde methods do the hard work. They have been set public in case you want to do customizations

◆ setMinMaxSize()

◆ setParams()

◆ setThresholdMethod()

◆ setThresholdParamRange()

◆ setThresholdParams()

◆ setWarpSize()

◆ thresHold()

◆ warp()

◆ warp_cylinder()

Member Data Documentation

◆ _candidates

◆ _params

◆ grey

◆ imagePyramid

◆ markerIdDetector

◆ thres