#include <visp3/klt/vpKltOpencv.h>

Public Member Functions
	vpKltOpencv ()

	vpKltOpencv (const vpKltOpencv &copy)

virtual	~vpKltOpencv ()

void	addFeature (const float &x, const float &y)

void	addFeature (const long &id, const float &x, const float &y)

void	addFeature (const cv::Point2f &f)

void	display (const vpImage< unsigned char > &I, const vpColor &color=vpColor::red, unsigned int thickness=1)

int	getBlockSize () const

void	getFeature (const int &index, long &id, float &x, float &y) const

std::vector< cv::Point2f >	getFeatures () const

std::vector< long >	getFeaturesId () const

double	getHarrisFreeParameter () const

int	getMaxFeatures () const

double	getMinDistance () const

int	getNbFeatures () const

int	getNbPrevFeatures () const

std::vector< cv::Point2f >	getPrevFeatures () const

int	getPyramidLevels () const

double	getQuality () const

int	getWindowSize () const

void	initTracking (const cv::Mat &I, const cv::Mat &mask=cv::Mat())

void	initTracking (const cv::Mat &I, const std::vector< cv::Point2f > &pts)

void	initTracking (const cv::Mat &I, const std::vector< cv::Point2f > &pts, const std::vector< long > &ids)

vpKltOpencv &	operator= (const vpKltOpencv &copy)

void	track (const cv::Mat &I)

void	setBlockSize (int blockSize)

void	setHarrisFreeParameter (double harris_k)

void	setInitialGuess (const std::vector< cv::Point2f > &guess_pts)

void	setInitialGuess (const std::vector< cv::Point2f > &init_pts, const std::vector< cv::Point2f > &guess_pts, const std::vector< long > &fid)

void	setMaxFeatures (int maxCount)

void	setMinDistance (double minDistance)

void	setMinEigThreshold (double minEigThreshold)

void	setPyramidLevels (int pyrMaxLevel)

void	setQuality (double qualityLevel)

void	setTrackerId (int tid)

void	setUseHarris (int useHarrisDetector)

void	setWindowSize (int winSize)

void	suppressFeature (const int &index)

Static Public Member Functions
static void	display (const vpImage< unsigned char > &I, const std::vector< cv::Point2f > &features, const vpColor &color=vpColor::green, unsigned int thickness=1)

static void	display (const vpImage< vpRGBa > &I, const std::vector< cv::Point2f > &features, const vpColor &color=vpColor::green, unsigned int thickness=1)

static void	display (const vpImage< unsigned char > &I, const std::vector< cv::Point2f > &features, const std::vector< long > &featuresid, const vpColor &color=vpColor::green, unsigned int thickness=1)

static void	display (const vpImage< vpRGBa > &I, const std::vector< cv::Point2f > &features, const std::vector< long > &featuresid, const vpColor &color=vpColor::green, unsigned int thickness=1)

Protected Attributes
cv::Mat	m_gray

cv::Mat	m_prevGray

std::vector< cv::Point2f >	m_points [2]

std::vector< long >	m_points_id

int	m_maxCount

cv::TermCriteria	m_termcrit

int	m_winSize

double	m_qualityLevel

double	m_minDistance

double	m_minEigThreshold

double	m_harris_k

int	m_blockSize

int	m_useHarrisDetector

int	m_pyrMaxLevel

long	m_next_points_id

bool	m_initial_guess

Detailed Description

Wrapper for the KLT (Kanade-Lucas-Tomasi) feature tracker implemented in OpenCV. Thus to enable this class OpenCV should be installed. Installation instructions are provided here https://visp.inria.fr/3rd_opencv.

The following example available in tutorial-klt-tracker.cpp shows how to use the main functions of the class.

#include <visp3/core/vpImageConvert.h>
#include <visp3/gui/vpDisplayOpenCV.h>
#include <visp3/io/vpVideoReader.h>
#include <visp3/klt/vpKltOpencv.h>
int main(int argc, const char *argv[])
{
#ifdef VISP_HAVE_OPENCV
  try {
    bool opt_init_by_click = false;
    for (int i = 0; i < argc; i++) {
      if (std::string(argv[i]) == "--init-by-click")
        opt_init_by_click = true;
      else if (std::string(argv[i]) == "--help") {
        std::cout << "Usage: " << argv[0] << " [--init-by-click] [--help]" << std::endl;
        return 0;
      }
    }
    vpVideoReader reader;
    reader.setFileName("video-postcard.mpeg");
    vpImage<unsigned char> I;
    reader.acquire(I);
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
    IplImage *cvI = NULL;
#else
    cv::Mat cvI;
#endif
    vpImageConvert::convert(I, cvI);
    vpDisplayOpenCV d(I, 0, 0, "Klt tracking");
    vpDisplay::display(I);
    vpDisplay::flush(I);
    vpKltOpencv tracker;
    tracker.setMaxFeatures(200);
    tracker.setWindowSize(10);
    tracker.setQuality(0.01);
    tracker.setMinDistance(15);
    tracker.setHarrisFreeParameter(0.04);
    tracker.setBlockSize(9);
    tracker.setUseHarris(1);
    tracker.setPyramidLevels(3);
    // Initialise the tracking
    if (opt_init_by_click) {
      vpMouseButton::vpMouseButtonType button = vpMouseButton::button1;
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
      std::vector<CvPoint2D32f> feature;
#else
      std::vector<cv::Point2f> feature;
#endif
      vpImagePoint ip;
      do {
        vpDisplay::displayText(I, 10, 10, "Left click to select a point, right to start tracking", vpColor::red);
        if (vpDisplay::getClick(I, ip, button, false)) {
          if (button == vpMouseButton::button1) {
            feature.push_back(cv::Point2f((float)ip.get_u(), (float)ip.get_v()));
            vpDisplay::displayCross(I, ip, 12, vpColor::green);
          }
        }
        vpDisplay::flush(I);
        vpTime::wait(20);
      } while (button != vpMouseButton::button3);
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
      tracker.initTracking(cvI, &feature[0], feature.size());
#else
      tracker.initTracking(cvI, feature);
#endif
    } else {
      tracker.initTracking(cvI);
    }
    std::cout << "Tracker initialized with " << tracker.getNbFeatures() << " features" << std::endl;
    while (!reader.end()) {
      reader.acquire(I);
      vpDisplay::display(I);
      vpImageConvert::convert(I, cvI);
      if (opt_init_by_click && reader.getFrameIndex() == reader.getFirstFrameIndex() + 20) {
        vpMouseButton::vpMouseButtonType button = vpMouseButton::button1;
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
        std::vector<CvPoint2D32f> feature;
#else
        std::vector<cv::Point2f> feature;
#endif
        vpImagePoint ip;
        do {
          vpDisplay::displayText(I, 10, 10, "Left click to select a point, right to start tracking", vpColor::red);
          if (vpDisplay::getClick(I, ip, button, false)) {
            if (button == vpMouseButton::button1) {
              feature.push_back(cv::Point2f((float)ip.get_u(), (float)ip.get_v()));
              vpDisplay::displayCross(I, ip, 12, vpColor::green);
            }
          }
          vpDisplay::flush(I);
          vpTime::wait(20);
        } while (button != vpMouseButton::button3);
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
        tracker.initTracking(cvI, &feature[0], feature.size());
#else
        tracker.initTracking(cvI, feature);
#endif
      }
      tracker.track(cvI);
      tracker.display(I, vpColor::red);
      vpDisplay::flush(I);
    }
    vpDisplay::getClick(I);
#if (VISP_HAVE_OPENCV_VERSION < 0x020408)
    cvReleaseImage(&cvI);
#endif
    return 0;
  } catch (const vpException &e) {
    std::cout << "Catch an exception: " << e << std::endl;
  }
#else
  (void)argc;
  (void)argv;
#endif
}

A line by line explanation is provided in Tutorial: Keypoint tracking.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 78 of file vpKltOpencv.h.

Constructor & Destructor Documentation

◆ vpKltOpencv() [1/2]

vpKltOpencv::vpKltOpencv ( )

Default constructor.

Definition at line 61 of file vpKltOpencv.cpp.

References m_termcrit.

Referenced by suppressFeature().

◆ vpKltOpencv() [2/2]

vpKltOpencv::vpKltOpencv ( const vpKltOpencv & copy )

Copy constructor.

Definition at line 72 of file vpKltOpencv.cpp.

◆ ~vpKltOpencv()

vpKltOpencv::~vpKltOpencv ( )

virtual

Definition at line 106 of file vpKltOpencv.cpp.

Referenced by suppressFeature().

Member Function Documentation

◆ addFeature() [1/3]

void vpKltOpencv::addFeature	(	const float &	x,
		const float &	y
	)

Add a keypoint at the end of the feature list. The id of the feature is set to ensure that it is unique.

Parameters

x,y	: Coordinates of the feature in the image.

Examples:: tutorial-klt-tracker-with-reinit.cpp.

Definition at line 517 of file vpKltOpencv.cpp.

References m_next_points_id, m_points, and m_points_id.

Referenced by suppressFeature().

◆ addFeature() [2/3]

void vpKltOpencv::addFeature	(	const long &	id,
		const float &	x,
		const float &	y
	)

Add a keypoint at the end of the feature list.

Warning: This function doesn't ensure that the id of the feature is unique. You should rather use addFeature(const float &, const float &) or addFeature(const cv::Point2f &).

Parameters

id	: Feature id. Should be unique
x,y	: Coordinates of the feature in the image.

Definition at line 536 of file vpKltOpencv.cpp.

References m_next_points_id, m_points, and m_points_id.

◆ addFeature() [3/3]

void vpKltOpencv::addFeature ( const cv::Point2f & f )

Add a keypoint at the end of the feature list. The id of the feature is set to ensure that it is unique.

Parameters

f	: Coordinates of the feature in the image.

Definition at line 552 of file vpKltOpencv.cpp.

References m_next_points_id, m_points, and m_points_id.

◆ display() [1/5]

void vpKltOpencv::display	(	const vpImage< unsigned char > &	I,
		const vpColor &	color = `vpColor::red`,
		unsigned int	thickness = `1`
	)

Display features position and id.

Parameters

I	: Image used as background. Display should be initialized on it.
color	: Color used to display the features.
thickness	: Thickness of the drawings.

Examples:: trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 217 of file vpKltOpencv.cpp.

References m_points, and m_points_id.

Referenced by suppressFeature().

◆ display() [2/5]

void vpKltOpencv::display	(	const vpImage< unsigned char > &	I,
		const std::vector< cv::Point2f > &	features,
		const vpColor &	color = `vpColor::green`,
		unsigned int	thickness = `1`
	)

static

Display features list.

Parameters

I	: The image used as background.
features	: Vector of features.
color	: Color used to display the points.
thickness	: Thickness of the points.

Definition at line 234 of file vpKltOpencv.cpp.

References vpDisplay::displayCross(), vpMath::round(), vpImagePoint::set_u(), and vpImagePoint::set_v().

◆ display() [3/5]

void vpKltOpencv::display	(	const vpImage< vpRGBa > &	I,
		const std::vector< cv::Point2f > &	features,
		const vpColor &	color = `vpColor::green`,
		unsigned int	thickness = `1`
	)

static

Display features list.

Parameters

I	: The image used as background.
features	: Vector of features.
color	: Color used to display the points.
thickness	: Thickness of the points.

Definition at line 257 of file vpKltOpencv.cpp.

References vpDisplay::displayCross(), vpMath::round(), vpImagePoint::set_u(), and vpImagePoint::set_v().

◆ display() [4/5]

void vpKltOpencv::display	(	const vpImage< unsigned char > &	I,
		const std::vector< cv::Point2f > &	features,
		const std::vector< long > &	featuresid,
		const vpColor &	color = `vpColor::green`,
		unsigned int	thickness = `1`
	)

static

Display features list with ids.

Parameters

I	: The image used as background.
features	: Vector of features.
featuresid	: Vector of ids corresponding to the features.
color	: Color used to display the points.
thickness	: Thickness of the points

Definition at line 282 of file vpKltOpencv.cpp.

References vpDisplay::displayCross(), vpDisplay::displayText(), vpMath::round(), vpImagePoint::set_u(), and vpImagePoint::set_v().

◆ display() [5/5]

void vpKltOpencv::display	(	const vpImage< vpRGBa > &	I,
		const std::vector< cv::Point2f > &	features,
		const std::vector< long > &	featuresid,
		const vpColor &	color = `vpColor::green`,
		unsigned int	thickness = `1`
	)

static

Display features list with ids.

Parameters

I	: The image used as background.
features	: Vector of features.
featuresid	: Vector of ids corresponding to the features.
color	: Color used to display the points.
thickness	: Thickness of the points

Definition at line 312 of file vpKltOpencv.cpp.

References vpDisplay::displayCross(), vpDisplay::displayText(), vpMath::round(), vpImagePoint::set_u(), and vpImagePoint::set_v().

◆ getBlockSize()

int vpKltOpencv::getBlockSize ( ) const

inline

Get the size of the averaging block used to track the features.

Definition at line 102 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ getFeature()

void vpKltOpencv::getFeature	(	const int &	index,
		long &	id,
		float &	x,
		float &	y
	)		const

Get the 'index'th feature image coordinates. Beware that getFeature(i,...) may not represent the same feature before and after a tracking iteration (if a feature is lost, features are shifted in the array).

Parameters

index	: Index of feature.
id	: id of the feature.
x	: x coordinate.
y	: y coordinate.

Examples:: tutorial-klt-tracker-with-reinit.cpp.

Definition at line 199 of file vpKltOpencv.cpp.

References vpException::badValue, m_points, and m_points_id.

Referenced by vpMbtDistanceKltCylinder::computeNbDetectedCurrent(), vpMbtDistanceKltPoints::computeNbDetectedCurrent(), vpMbKltTracker::getKltImagePoints(), vpMbKltTracker::getKltImagePointsWithId(), vpMbtDistanceKltPoints::init(), vpMbtDistanceKltCylinder::init(), and suppressFeature().

◆ getFeatures()

std::vector<cv::Point2f> vpKltOpencv::getFeatures ( ) const

inline

Get the list of current features.

Examples:: tutorial-klt-tracker-with-reinit.cpp.

Definition at line 105 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::getKltPoints().

◆ getFeaturesId()

std::vector<long> vpKltOpencv::getFeaturesId ( ) const

inline

Get the unique id of each feature.

Definition at line 108 of file vpKltOpencv.h.

◆ getHarrisFreeParameter()

double vpKltOpencv::getHarrisFreeParameter ( ) const

inline

Get the free parameter of the Harris detector.

Definition at line 111 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ getMaxFeatures()

int vpKltOpencv::getMaxFeatures ( ) const

inline

Get the list of lost feature.

Get the maximum number of features to track in the image.

Examples:: tutorial-klt-tracker-with-reinit.cpp.

Definition at line 115 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::setPose().

◆ getMinDistance()

double vpKltOpencv::getMinDistance ( ) const

inline

Get the minimal Euclidean distance between detected corners during initialization.

Examples:: tutorial-klt-tracker-with-reinit.cpp.

Definition at line 118 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ getNbFeatures()

int vpKltOpencv::getNbFeatures ( ) const

inline

Get the number of current features.

Examples:: tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 120 of file vpKltOpencv.h.

Referenced by vpMbtDistanceKltCylinder::computeNbDetectedCurrent(), vpMbtDistanceKltPoints::computeNbDetectedCurrent(), vpMbKltTracker::getKltImagePoints(), vpMbKltTracker::getKltImagePointsWithId(), vpMbKltTracker::getKltNbPoints(), vpMbKltTracker::getNbKltPoints(), vpMbtDistanceKltPoints::init(), and vpMbtDistanceKltCylinder::init().

◆ getNbPrevFeatures()

int vpKltOpencv::getNbPrevFeatures ( ) const

inline

Get the number of previous features.

Definition at line 122 of file vpKltOpencv.h.

◆ getPrevFeatures()

std::vector<cv::Point2f> vpKltOpencv::getPrevFeatures ( ) const

inline

Get the list of previous features.

Definition at line 125 of file vpKltOpencv.h.

◆ getPyramidLevels()

int vpKltOpencv::getPyramidLevels ( ) const

inline

Get the list of features id.

Get the maximal pyramid level.

Definition at line 130 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ getQuality()

double vpKltOpencv::getQuality ( ) const

inline

Get the parameter characterizing the minimal accepted quality of image corners.

Definition at line 133 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ getWindowSize()

int vpKltOpencv::getWindowSize ( ) const

inline

Get the window size used to refine the corner locations.

Definition at line 135 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::setKltOpencv().

◆ initTracking() [1/3]

void vpKltOpencv::initTracking	(	const cv::Mat &	I,
		const cv::Mat &	mask = `cv::Mat()`
	)

Initialise the tracking by extracting KLT keypoints on the provided image.

Parameters

I	: Grey level image used as input. This image should have only 1 channel.
mask	: Image mask used to restrict the keypoint detection area. If mask is NULL, all the image will be considered.

Exceptions

vpTrackingException::initializationError : If the image I is not initialized, or if the image or the mask have bad coding format.

Examples:: trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 118 of file vpKltOpencv.cpp.

References m_blockSize, m_gray, m_harris_k, m_maxCount, m_minDistance, m_next_points_id, m_points, m_points_id, m_qualityLevel, m_termcrit, and m_winSize.

Referenced by vpMbKltTracker::reinit(), and suppressFeature().

◆ initTracking() [2/3]

void vpKltOpencv::initTracking	(	const cv::Mat &	I,
		const std::vector< cv::Point2f > &	pts
	)

Set the points that will be used as initialization during the next call to track().

Parameters

I	: Input image.
pts	: Vector of points that should be tracked.

Definition at line 474 of file vpKltOpencv.cpp.

References m_gray, m_initial_guess, m_next_points_id, m_points, and m_points_id.

◆ initTracking() [3/3]

void vpKltOpencv::initTracking	(	const cv::Mat &	I,
		const std::vector< cv::Point2f > &	pts,
		const std::vector< long > &	ids
	)

Definition at line 487 of file vpKltOpencv.cpp.

References m_gray, m_initial_guess, m_next_points_id, m_points, and m_points_id.

◆ operator=()

vpKltOpencv & vpKltOpencv::operator= ( const vpKltOpencv & copy )

Copy operator.

Definition at line 83 of file vpKltOpencv.cpp.

References m_blockSize, m_gray, m_harris_k, m_initial_guess, m_maxCount, m_minDistance, m_minEigThreshold, m_next_points_id, m_points, m_points_id, m_prevGray, m_pyrMaxLevel, m_qualityLevel, m_termcrit, m_useHarrisDetector, and m_winSize.

Referenced by suppressFeature().

◆ setBlockSize()

void vpKltOpencv::setBlockSize ( int blockSize )

Set the size of the averaging block used to track the features.

Warning: The input is a signed integer to be compatible with OpenCV. However, it must be a positive integer.

Parameters

blockSize : Size of an average block for computing a derivative covariation matrix over each pixel neighborhood. Default value is set to 3.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 399 of file vpKltOpencv.cpp.

References m_blockSize.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ setHarrisFreeParameter()

void vpKltOpencv::setHarrisFreeParameter ( double harris_k )

Set the free parameter of the Harris detector.

Parameters

harris_k : Free parameter of the Harris detector. Default value is set to 0.04.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 364 of file vpKltOpencv.cpp.

References m_harris_k.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ setInitialGuess() [1/2]

void vpKltOpencv::setInitialGuess ( const std::vector< cv::Point2f > & guess_pts )

Set the points that will be used as initial guess during the next call to track(). A typical usage of this function is to predict the position of the features before the next call to track().

Parameters

guess_pts : Vector of points that should be tracked. The size of this vector should be the same as the one returned by getFeatures(). If this is not the case, an exception is returned. Note also that the id of the points is not modified.

See also: initTracking()

Definition at line 423 of file vpKltOpencv.cpp.

References vpException::badValue, m_initial_guess, and m_points.

Referenced by vpMbKltTracker::setPose(), and suppressFeature().

◆ setInitialGuess() [2/2]

void vpKltOpencv::setInitialGuess	(	const std::vector< cv::Point2f > &	init_pts,
		const std::vector< cv::Point2f > &	guess_pts,
		const std::vector< long > &	fid
	)

Set the points that will be used as initial guess during the next call to track(). A typical usage of this function is to predict the position of the features before the next call to track().

Parameters

init_pts	: Initial points (could be obtained from getPrevFeatures() or getFeatures()).
guess_pts	: Prediction of the new position of the initial points. The size of this vector must be the same as the size of the vector of initial points.
fid	: Identifiers of the initial points.

See also: getPrevFeatures(),getPrevFeaturesId; getFeatures(), getFeaturesId; initTracking()

Definition at line 450 of file vpKltOpencv.cpp.

References vpException::badValue, m_initial_guess, m_points, and m_points_id.

◆ setMaxFeatures()

void vpKltOpencv::setMaxFeatures ( int maxCount )

Set the maximum number of features to track in the image.

Parameters

maxCount : Maximum number of features to detect and track. Default value is set to 500.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 334 of file vpKltOpencv.cpp.

References m_maxCount.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), suppressFeature(), and vpMbKltTracker::vpMbKltTracker().

◆ setMinDistance()

void vpKltOpencv::setMinDistance ( double minDistance )

Set the minimal Euclidean distance between detected corners during initialization.

Parameters

minDistance : Minimal possible Euclidean distance between the detected corners. Default value is set to 15.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 381 of file vpKltOpencv.cpp.

References m_minDistance.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ setMinEigThreshold()

void vpKltOpencv::setMinEigThreshold ( double minEigThreshold )

Set the minimal eigen value threshold used to reject a point during the tracking.

Parameters

minEigThreshold : Minimal eigen value threshold. Default value is set to 1e-4.

Definition at line 388 of file vpKltOpencv.cpp.

References m_minEigThreshold.

◆ setPyramidLevels()

void vpKltOpencv::setPyramidLevels ( int pyrMaxLevel )

Set the maximal pyramid level. If the level is zero, then no pyramid is computed for the optical flow.

Parameters

pyrMaxLevel : 0-based maximal pyramid level number; if set to 0, pyramids are not used (single level), if set to 1, two levels are used, and so on. Default value is set to 3.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 409 of file vpKltOpencv.cpp.

References m_pyrMaxLevel.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ setQuality()

void vpKltOpencv::setQuality ( double qualityLevel )

Set the parameter characterizing the minimal accepted quality of image corners.

Parameters

qualityLevel : Quality level parameter. Default value is set to 0.01. The parameter value is multiplied by the best corner quality measure, which is the minimal eigenvalue or the Harris function response. The corners with the quality measure less than the product are rejected. For example, if the best corner has the quality measure = 1500, and the qualityLevel=0.01, then all the corners with the quality measure less than 15 are rejected.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 356 of file vpKltOpencv.cpp.

References m_qualityLevel.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ setTrackerId()

void vpKltOpencv::setTrackerId ( int tid )

inline

Does nothing. Just here for compat with previous releases that use OpenCV C api to do the tracking.

Examples:: trackKltOpencv.cpp.

Definition at line 155 of file vpKltOpencv.h.

Referenced by vpMbKltTracker::resetTracker(), and vpMbKltTracker::vpMbKltTracker().

◆ setUseHarris()

void vpKltOpencv::setUseHarris ( int useHarrisDetector )

Set the parameter indicating whether to use a Harris detector or the minimal eigenvalue of gradient matrices for corner detection.

Parameters

useHarrisDetector : If 1 (default value), use the Harris detector. If 0 use the eigenvalue.

Examples:: trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 372 of file vpKltOpencv.cpp.

References m_useHarrisDetector.

Referenced by vpMbKltTracker::resetTracker(), and vpMbKltTracker::vpMbKltTracker().

◆ setWindowSize()

void vpKltOpencv::setWindowSize ( int winSize )

Set the window size used to refine the corner locations.

Parameters

winSize : Half of the side length of the search window. Default value is set to 10. For example, if winSize=5 , then a 5*2+1 $\times$ 5*2+1 = 11 $\times$ 11 search window is used.

Examples:: mbtEdgeKltMultiTracking.cpp, mbtEdgeKltTracking.cpp, mbtGenericTracking.cpp, mbtGenericTracking2.cpp, mbtGenericTrackingDepth.cpp, mbtKltMultiTracking.cpp, mbtKltTracking.cpp, testGenericTracker.cpp, trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, tutorial-klt-tracker.cpp, tutorial-mb-generic-tracker-apriltag-rs2.cpp, tutorial-mb-generic-tracker-apriltag-webcam.cpp, tutorial-mb-generic-tracker-full.cpp, tutorial-mb-generic-tracker-live.cpp, tutorial-mb-generic-tracker-stereo-mono.cpp, tutorial-mb-generic-tracker.cpp, tutorial-mb-hybrid-tracker.cpp, tutorial-mb-klt-tracker.cpp, tutorial-mb-tracker-full.cpp, tutorial-mb-tracker-stereo-mono.cpp, and tutorial-mb-tracker.cpp.

Definition at line 343 of file vpKltOpencv.cpp.

References m_winSize.

Referenced by vpMbEdgeKltTracker::loadConfigFile(), vpMbKltTracker::loadConfigFile(), vpMbKltTracker::resetTracker(), vpMbKltTracker::setKltOpencv(), and vpMbKltTracker::vpMbKltTracker().

◆ suppressFeature()

void vpKltOpencv::suppressFeature ( const int & index )

Remove the feature with the given index as parameter.

Parameters

index : Index of the feature to remove.

Definition at line 562 of file vpKltOpencv.cpp.

References addFeature(), vpException::badValue, vpImage< Type >::bitmap, display(), vpDisplay::displayCross(), vpDisplay::displayText(), getFeature(), vpTrackingException::initializationError, initTracking(), m_points, m_points_id, vpException::memoryAllocationError, operator=(), vpMath::round(), vpImagePoint::set_u(), vpImagePoint::set_v(), setInitialGuess(), setMaxFeatures(), track(), vpERROR_TRACE, vpKltOpencv(), and ~vpKltOpencv().

◆ track()

void vpKltOpencv::track ( const cv::Mat & I )

Track KLT keypoints using the iterative Lucas-Kanade method with pyramids.

Parameters

I	: Input image.

Examples:: trackKltOpencv.cpp, tutorial-klt-tracker-live-v4l2.cpp, tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 147 of file vpKltOpencv.cpp.

References vpTrackingException::fatalError, m_gray, m_initial_guess, m_minEigThreshold, m_points, m_points_id, m_prevGray, m_pyrMaxLevel, m_termcrit, and m_winSize.

Referenced by vpMbKltTracker::preTracking(), and suppressFeature().

Member Data Documentation

◆ m_blockSize

int vpKltOpencv::m_blockSize

protected

Definition at line 171 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and setBlockSize().

◆ m_gray

cv::Mat vpKltOpencv::m_gray

protected

Definition at line 161 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and track().

◆ m_harris_k

double vpKltOpencv::m_harris_k

protected

Definition at line 170 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and setHarrisFreeParameter().

◆ m_initial_guess

bool vpKltOpencv::m_initial_guess

protected

Definition at line 175 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), setInitialGuess(), and track().

◆ m_maxCount

int vpKltOpencv::m_maxCount

protected

Definition at line 164 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and setMaxFeatures().

◆ m_minDistance

double vpKltOpencv::m_minDistance

protected

Definition at line 168 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and setMinDistance().

◆ m_minEigThreshold

double vpKltOpencv::m_minEigThreshold

protected

Definition at line 169 of file vpKltOpencv.h.

Referenced by operator=(), setMinEigThreshold(), and track().

◆ m_next_points_id

long vpKltOpencv::m_next_points_id

protected

Definition at line 174 of file vpKltOpencv.h.

Referenced by addFeature(), initTracking(), and operator=().

◆ m_points

std::vector<cv::Point2f> vpKltOpencv::m_points[2]

protected

Previous [0] and current [1] keypoint location.

Definition at line 162 of file vpKltOpencv.h.

Referenced by addFeature(), display(), getFeature(), initTracking(), operator=(), setInitialGuess(), suppressFeature(), and track().

◆ m_points_id

std::vector<long> vpKltOpencv::m_points_id

protected

Keypoint id.

Definition at line 163 of file vpKltOpencv.h.

Referenced by addFeature(), display(), getFeature(), initTracking(), operator=(), setInitialGuess(), suppressFeature(), and track().

◆ m_prevGray

cv::Mat vpKltOpencv::m_prevGray

protected

Definition at line 161 of file vpKltOpencv.h.

Referenced by operator=(), and track().

◆ m_pyrMaxLevel

int vpKltOpencv::m_pyrMaxLevel

protected

Definition at line 173 of file vpKltOpencv.h.

Referenced by operator=(), setPyramidLevels(), and track().

◆ m_qualityLevel

double vpKltOpencv::m_qualityLevel

protected

Definition at line 167 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), and setQuality().

◆ m_termcrit

cv::TermCriteria vpKltOpencv::m_termcrit

protected

Definition at line 165 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), track(), and vpKltOpencv().

◆ m_useHarrisDetector

int vpKltOpencv::m_useHarrisDetector

protected

Definition at line 172 of file vpKltOpencv.h.

Referenced by operator=(), and setUseHarris().

◆ m_winSize

int vpKltOpencv::m_winSize

protected

Definition at line 166 of file vpKltOpencv.h.

Referenced by initTracking(), operator=(), setWindowSize(), and track().

Public Member Functions

Static Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ vpKltOpencv() [1/2]

◆ vpKltOpencv() [2/2]

◆ ~vpKltOpencv()

Member Function Documentation

◆ addFeature() [1/3]

◆ addFeature() [2/3]

◆ addFeature() [3/3]

◆ display() [1/5]

◆ display() [2/5]

◆ display() [3/5]

◆ display() [4/5]

◆ display() [5/5]

◆ getBlockSize()

◆ getFeature()

◆ getFeatures()

◆ getFeaturesId()

◆ getHarrisFreeParameter()

◆ getMaxFeatures()

◆ getMinDistance()

◆ getNbFeatures()

◆ getNbPrevFeatures()

◆ getPrevFeatures()

◆ getPyramidLevels()

◆ getQuality()

◆ getWindowSize()

◆ initTracking() [1/3]

◆ initTracking() [2/3]

◆ initTracking() [3/3]

◆ operator=()

◆ setBlockSize()

◆ setHarrisFreeParameter()

◆ setInitialGuess() [1/2]

◆ setInitialGuess() [2/2]

◆ setMaxFeatures()

◆ setMinDistance()

◆ setMinEigThreshold()

◆ setPyramidLevels()

◆ setQuality()

◆ setTrackerId()

◆ setUseHarris()

◆ setWindowSize()

◆ suppressFeature()

◆ track()

Member Data Documentation

◆ m_blockSize

◆ m_gray

◆ m_harris_k

◆ m_initial_guess

◆ m_maxCount

◆ m_minDistance

◆ m_minEigThreshold

◆ m_next_points_id

◆ m_points

◆ m_points_id

◆ m_prevGray

◆ m_pyrMaxLevel

◆ m_qualityLevel

◆ m_termcrit

◆ m_useHarrisDetector

◆ m_winSize