#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) const

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

Friends
void	to_json (nlohmann::json &j, const vpKltOpencv &array)

void	from_json (const nlohmann::json &j, vpKltOpencv &array)

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 <iostream>
 
#include <visp3/core/vpConfig.h>
 
#if defined(HAVE_OPENCV_HIGHGUI) && defined(HAVE_OPENCV_IMGPROC) && defined(HAVE_OPENCV_VIDEO) && defined(HAVE_OPENCV_VIDEOIO)
 
#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 ENABLE_VISP_NAMESPACE
  using namespace VISP_NAMESPACE_NAME;
#endif
 
  try {
    std::string opt_videoname = "video-postcard.mp4";
    bool opt_init_by_click = false;
    unsigned int opt_subsample = 1;
    for (int i = 1; i < argc; i++) {
      if (std::string(argv[i]) == "--videoname") {
        opt_videoname = std::string(argv[++i]);
      }
      else if (std::string(argv[i]) == "--init-by-click") {
        opt_init_by_click = true;
      }
      else if (std::string(argv[i]) == "--subsample") {
        opt_subsample = static_cast<unsigned int>(std::atoi(argv[++i]));
      }
      else if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h") {
        std::cout << "Usage: " << argv[0]
          << " [--videoname <video name>] [--subsample <scale factor>] [--init-by-click]"
          << " [--help] [-h]" << std::endl;
        return EXIT_SUCCESS;
      }
    }
 
    vpVideoReader reader;
    reader.setFileName(opt_videoname);
 
    vpImage<unsigned char> I, Iacq;
    reader.acquire(Iacq);
    Iacq.subsample(opt_subsample, opt_subsample, I);
 
    cv::Mat cvI;
    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;
      std::vector<cv::Point2f> feature;
      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);
      tracker.initTracking(cvI, feature);
    }
    else {
      tracker.initTracking(cvI);
    }
 
    std::cout << "Tracker initialized with " << tracker.getNbFeatures() << " features" << std::endl;
 
    while (!reader.end()) {
      double t = vpTime::measureTimeMs();
      reader.acquire(Iacq);
      Iacq.subsample(opt_subsample, opt_subsample, I);
      vpDisplay::display(I);
 
      vpImageConvert::convert(I, cvI);
 
      if (opt_init_by_click && reader.getFrameIndex() == reader.getFirstFrameIndex() + 20) {
        vpMouseButton::vpMouseButtonType button = vpMouseButton::button1;
        std::vector<cv::Point2f> feature;
        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);
        tracker.initTracking(cvI, feature);
      }
 
      tracker.track(cvI);
 
      tracker.display(I, vpColor::red);
 
      vpDisplay::displayText(I, 10, 10, "Click to quit", vpColor::red);
      if (vpDisplay::getClick(I, false))
        break;
 
      vpDisplay::flush(I);
      if (!reader.isVideoFormat()) {
        vpTime::wait(t, 40);
      }
    }
 
    vpDisplay::getClick(I);
  }
  catch (const vpException &e) {
    std::cout << "Catch an exception: " << e << std::endl;
    return EXIT_FAILURE;
  }
  return EXIT_SUCCESS;
}
 
#else
 
int main()
{
#if !defined(HAVE_OPENCV_HIGHGUI)
  std::cout << "This tutorial needs OpenCV highgui module that is missing." << std::endl;
#endif
#if !defined(HAVE_OPENCV_IMGPROC)
  std::cout << "This tutorial needs OpenCV imgproc module that is missing." << std::endl;
#endif
#if !defined(HAVE_OPENCV_VIDEO)
  std::cout << "This tutorial needs OpenCV video module that is missing." << std::endl;
#endif
#if !defined(HAVE_OPENCV_VIDEOIO)
  std::cout << "This tutorial needs OpenCV videoio module that is missing." << std::endl;
#endif
}
 
#endif

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

Definition at line 78 of file vpKltOpencv.h.

Constructor & Destructor Documentation

◆ vpKltOpencv() [1/2]

BEGIN_VISP_NAMESPACE vpKltOpencv::vpKltOpencv ( )

Default constructor.

Definition at line 53 of file vpKltOpencv.cpp.

References m_termcrit.

◆ vpKltOpencv() [2/2]

vpKltOpencv::vpKltOpencv ( const vpKltOpencv & copy )

Copy constructor.

Definition at line 61 of file vpKltOpencv.cpp.

◆ ~vpKltOpencv()

vpKltOpencv::~vpKltOpencv ( )

virtual

Destructor.

Definition at line 92 of file vpKltOpencv.cpp.

Member Function Documentation

◆ addFeature() [1/3]

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 309 of file vpKltOpencv.cpp.

References m_next_points_id, m_points, and m_points_id.

◆ addFeature() [2/3]

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 293 of file vpKltOpencv.cpp.

References m_next_points_id, m_points, and m_points_id.

◆ addFeature() [3/3]

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 300 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 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 195 of file vpKltOpencv.cpp.

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

◆ 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 173 of file vpKltOpencv.cpp.

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

◆ display() [3/5]

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

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

Definition at line 168 of file vpKltOpencv.cpp.

References m_points, and m_points_id.

◆ display() [4/5]

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 211 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 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 184 of file vpKltOpencv.cpp.

References vpDisplay::displayCross(), 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 174 of file vpKltOpencv.h.

◆ 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.

Definition at line 157 of file vpKltOpencv.cpp.

References vpException::badValue, m_points, and m_points_id.

◆ 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 188 of file vpKltOpencv.h.

◆ getFeaturesId()

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

inline

Get the unique id of each feature.

Definition at line 191 of file vpKltOpencv.h.

◆ getHarrisFreeParameter()

double vpKltOpencv::getHarrisFreeParameter ( ) const

inline

Get the free parameter of the Harris detector.

Definition at line 194 of file vpKltOpencv.h.

◆ getMaxFeatures()

int vpKltOpencv::getMaxFeatures ( ) const

inline

Get the list of lost feature.

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

Definition at line 198 of file vpKltOpencv.h.

◆ 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 201 of file vpKltOpencv.h.

◆ 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 203 of file vpKltOpencv.h.

◆ getNbPrevFeatures()

int vpKltOpencv::getNbPrevFeatures ( ) const

inline

Get the number of previous features.

Definition at line 205 of file vpKltOpencv.h.

◆ getPrevFeatures()

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

inline

Get the list of previous features.

Definition at line 208 of file vpKltOpencv.h.

◆ getPyramidLevels()

int vpKltOpencv::getPyramidLevels ( ) const

inline

Get the list of features id.

Get the maximal pyramid level.

Definition at line 213 of file vpKltOpencv.h.

◆ getQuality()

double vpKltOpencv::getQuality ( ) const

inline

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

Definition at line 216 of file vpKltOpencv.h.

◆ getWindowSize()

int vpKltOpencv::getWindowSize ( ) const

inline

Get the window size used to refine the corner locations.

Definition at line 218 of file vpKltOpencv.h.

◆ 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 nullptr, 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: tutorial-klt-tracker-live.cpp, tutorial-klt-tracker-with-reinit.cpp, and tutorial-klt-tracker.cpp.

Definition at line 94 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.

◆ 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 256 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
	)

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.
ids	: Corresponding point ids.

Definition at line 269 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 69 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.

◆ setBlockSize()

void vpKltOpencv::setBlockSize ( int blockSize )

inline

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 covariance matrix over each pixel neighborhood. Default value is set to 3.

Definition at line 272 of file vpKltOpencv.h.

◆ setHarrisFreeParameter()

void vpKltOpencv::setHarrisFreeParameter ( double harris_k )

inline

Set the free parameter of the Harris detector.

Parameters

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

Definition at line 280 of file vpKltOpencv.h.

◆ 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 227 of file vpKltOpencv.cpp.

References vpException::badValue, m_initial_guess, and m_points.

◆ 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 240 of file vpKltOpencv.cpp.

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

◆ setMaxFeatures()

void vpKltOpencv::setMaxFeatures ( int maxCount )

inline

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.

Definition at line 320 of file vpKltOpencv.h.

◆ setMinDistance()

void vpKltOpencv::setMinDistance ( double minDistance )

inline

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.

Definition at line 329 of file vpKltOpencv.h.

◆ setMinEigThreshold()

void vpKltOpencv::setMinEigThreshold ( double minEigThreshold )

inline

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 338 of file vpKltOpencv.h.

◆ setPyramidLevels()

void vpKltOpencv::setPyramidLevels ( int pyrMaxLevel )

inline

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.

Definition at line 348 of file vpKltOpencv.h.

◆ setQuality()

void vpKltOpencv::setQuality ( double qualityLevel )

inline

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.

Definition at line 361 of file vpKltOpencv.h.

◆ 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.

Definition at line 365 of file vpKltOpencv.h.

◆ setUseHarris()

void vpKltOpencv::setUseHarris ( int useHarrisDetector )

inline

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

Definition at line 373 of file vpKltOpencv.h.

◆ setWindowSize()

void vpKltOpencv::setWindowSize ( int winSize )

inline

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.

Definition at line 382 of file vpKltOpencv.h.

◆ 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 315 of file vpKltOpencv.cpp.

References vpException::badValue, m_points, and m_points_id.

◆ track()

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

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

Parameters

I	: Input image.

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

Definition at line 117 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.

Friends And Related Function Documentation

◆ from_json

void from_json	(	const nlohmann::json &	j,
		vpKltOpencv &	array
	)

friend

Definition at line 430 of file vpKltOpencv.h.

◆ to_json

void to_json	(	nlohmann::json &	j,
		const vpKltOpencv &	array
	)

friend

Definition at line 416 of file vpKltOpencv.h.

Member Data Documentation

◆ m_blockSize

int vpKltOpencv::m_blockSize

protected

Block size.

Definition at line 408 of file vpKltOpencv.h.

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

◆ m_gray

cv::Mat vpKltOpencv::m_gray

protected

Gray image.

Definition at line 397 of file vpKltOpencv.h.

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

◆ m_harris_k

double vpKltOpencv::m_harris_k

protected

Harris parameter.

Definition at line 407 of file vpKltOpencv.h.

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

◆ m_initial_guess

bool vpKltOpencv::m_initial_guess

protected

true when initial guess is provided

Definition at line 412 of file vpKltOpencv.h.

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

◆ m_maxCount

int vpKltOpencv::m_maxCount

protected

Max number of keypoints.

Definition at line 401 of file vpKltOpencv.h.

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

◆ m_minDistance

double vpKltOpencv::m_minDistance

protected

Mins distance between keypoints.

Definition at line 405 of file vpKltOpencv.h.

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

◆ m_minEigThreshold

double vpKltOpencv::m_minEigThreshold

protected

Min eigen threshold.

Definition at line 406 of file vpKltOpencv.h.

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

◆ m_next_points_id

long vpKltOpencv::m_next_points_id

protected

Id for the newt keypoint.

Definition at line 411 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 399 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 400 of file vpKltOpencv.h.

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

◆ m_prevGray

cv::Mat vpKltOpencv::m_prevGray

protected

Previous gray image.

Definition at line 398 of file vpKltOpencv.h.

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

◆ m_pyrMaxLevel

int vpKltOpencv::m_pyrMaxLevel

protected

Pyramid max level.

Definition at line 410 of file vpKltOpencv.h.

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

◆ m_qualityLevel

double vpKltOpencv::m_qualityLevel

protected

Quality level.

Definition at line 404 of file vpKltOpencv.h.

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

◆ m_termcrit

cv::TermCriteria vpKltOpencv::m_termcrit

protected

Term criteria.

Definition at line 402 of file vpKltOpencv.h.

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

◆ m_useHarrisDetector

int vpKltOpencv::m_useHarrisDetector

protected

true to use Harris detector

Definition at line 409 of file vpKltOpencv.h.

Referenced by operator=().

◆ m_winSize

int vpKltOpencv::m_winSize

protected

Window criteria.

Definition at line 403 of file vpKltOpencv.h.

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

Public Member Functions

Static Public Member Functions

Protected Attributes

Friends

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()

Friends And Related Function Documentation

◆ from_json

◆ to_json

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