CVTrackedArucoCube Class Reference

OpenCV ArUco cube marker tracker class derived from CVTrackedAruco. More...

#include <CVTrackedArucoCube.h>

Inheritance diagram for CVTrackedArucoCube:

Public Member Functions
	CVTrackedArucoCube (string calibIniPath, float edgeLength)
bool	track (CVMat imageGray, CVMat imageBgr, CVCalibration *calib)
	Tracks the all Aruco markers in the given image for the first sceneview. More...
Public Member Functions inherited from CVTrackedAruco
	CVTrackedAruco (int arucoID, string calibIniPath)
const CVArucoParams &	params () const
Public Member Functions inherited from CVTracked
	CVTracked ()
virtual	~CVTracked ()=default
void	drawDetection (bool draw)
bool	isVisible ()
bool	drawDetection ()
CVMatx44f	objectViewMat ()

Public Attributes
CVRect	_roi = CVRect(0, 0, 0, 0)

Private Attributes
float	_edgeLength
Averaged< CVVec3f >	_averagePosition
AveragedQuat4f	_averageRotation

Additional Inherited Members
Static Public Member Functions inherited from CVTrackedAruco
static void	drawArucoMarkerBoard (int dictionaryId, int numMarkersX, int numMarkersY, float markerEdgeLengthM, float markerSepaM, const string &imgName, float dpi=254.0f, bool showImage=false)
	Helper function to draw and save an aruco marker board image. More...
static void	drawArucoMarker (int dictionaryId, int minMarkerId, int maxMarkerId, int markerSizePX=200)
	Helper function to draw and save an aruco marker set. More...
Static Public Member Functions inherited from CVTracked
static cv::Matx44f	createGLMatrix (const CVMat &tVec, const CVMat &rVec)
	Create an OpenGL 4x4 matrix from an OpenCV translation & rotation vector. More...
static void	createRvecTvec (const CVMatx44f &glMat, CVMat &tVec, CVMat &rVec)
	Creates the OpenCV rvec & tvec vectors from an column major OpenGL 4x4 matrix. More...
static CVMatx44f	calcObjectMatrix (const CVMatx44f &cameraObjectMat, const CVMatx44f &objectViewMat)
static CVVec3f	averageVector (vector< CVVec3f > vectors, vector< float > weights)
static SLQuat4f	averageQuaternion (vector< SLQuat4f > quaternions, vector< float > weights)
static void	resetTimes ()
	Resets all static variables. More...
Static Public Attributes inherited from CVTracked
static AvgFloat	trackingTimesMS
	Averaged time for video tracking in ms. More...
static AvgFloat	detectTimesMS
	Averaged time for video feature detection & description in ms. More...
static AvgFloat	detect1TimesMS
	Averaged time for video feature detection subpart 1 in ms. More...
static AvgFloat	detect2TimesMS
	Averaged time for video feature detection subpart 2 in ms. More...
static AvgFloat	matchTimesMS
	Averaged time for video feature matching in ms. More...
static AvgFloat	optFlowTimesMS
	Averaged time for video feature optical flow tracking in ms. More...
static AvgFloat	poseTimesMS
	Averaged time for video feature pose estimation in ms. More...
Protected Member Functions inherited from CVTrackedAruco
bool	trackAll (CVMat imageGray, CVMat imageBgr, CVCalibration *calib, CVRect roi=CVRect(0, 0, 0, 0))
Protected Attributes inherited from CVTrackedAruco
vector< int >	arucoIDs
	detected Aruco marker IDs More...
CVVMatx44f	objectViewMats
	object view matrices for all found markers More...
Protected Attributes inherited from CVTracked
bool	_isVisible
	Flag if marker is visible. More...
bool	_drawDetection
	Flag if detection should be drawn into image. More...
CVMatx44f	_objectViewMat
	view transformation matrix More...
HighResTimer	_timer
	High resolution timer. More...

Detailed Description

OpenCV ArUco cube marker tracker class derived from CVTrackedAruco.

Tracks a cube of ArUco markers and averages their values. The origin of the cube is in the center. The markers must be placed in the following manner: ID 0: front ID 1: right ID 2: back ID 3: left ID 4: top ID 5: bottom

Definition at line 97 of file CVTrackedArucoCube.h.

Constructor & Destructor Documentation

CVTrackedArucoCube()

CVTrackedArucoCube::CVTrackedArucoCube	(	string	calibIniPath,
		float	edgeLength
	)

Definition at line 21 of file CVTrackedArucoCube.cpp.

  : CVTrackedAruco(-1, std::move(calibIniPath)),
    _edgeLength(edgeLength),
    _averagePosition(2, CVVec3f(0.0f, 0.0f, 0.0f)),
    _averageRotation(2, SLQuat4f(0.0f, 0.0f, 0.0f, 1.0f))
{
}

Member Function Documentation

track()

bool CVTrackedArucoCube::track ( CVMat  imageGray, CVMat  imageBgr, CVCalibration *  calib  )

virtual

Tracks the all Aruco markers in the given image for the first sceneview.

Reimplemented from CVTrackedAruco.

Definition at line 29 of file CVTrackedArucoCube.cpp.

{
    PROFILE_FUNCTION();
 
    /////////////////
    // TRACK FACES //
    /////////////////
 
    if (!trackAll(imageGray, imageBgr, calib, _roi))
    {
        return false;
    }
 
    ///////////////////////////////////////////////
    // COLLECT FACE TRANSFORMATIONS AND WEIGHTS  //
    ///////////////////////////////////////////////
 
    vector<CVVec3f>  translations;
    vector<SLQuat4f> rotations;
    vector<float>    weights;
 
    for (size_t i = 0; i < arucoIDs.size(); i++)
    {
        // Convert the OpenCV matrix to an SL matrix
        SLMat4f faceViewMatrix(objectViewMats[i].val);
        faceViewMatrix.transpose();
 
        // Calculate how much this face contributes to the total transformation
        // The steeper a face is relative to the camera,
        // the less it should contribute because the accuracy is generally poorer in this case
        float weight = faceViewMatrix.axisZ().dot(SLVec3f::AXISZ);
 
        // Weights below 0.3 are very inaccurate
        // If the weight is negative, this means that the z axis is pointing the wrong way
        if (weight < 0.3f)
        {
            continue;
        }
 
        weight = Utils::clamp(weight, 0.0f, 1.0f);
 
        // Move to the center of the cube
        faceViewMatrix.translate(0.0f, 0.0f, -0.5f * _edgeLength);
 
        // Rotate face to cube space
        SLVec3f translation = faceViewMatrix.translation();
        if (arucoIDs[i] == 0)
            ;                                            // front (no rotation)
        else if (arucoIDs[i] == 1)
            faceViewMatrix.rotate(-90, SLVec3f::AXISY);  // right
        else if (arucoIDs[i] == 2)
            faceViewMatrix.rotate(-180, SLVec3f::AXISY); // back
        else if (arucoIDs[i] == 3)
            faceViewMatrix.rotate(90, SLVec3f::AXISY);   // left
        else if (arucoIDs[i] == 4)
            faceViewMatrix.rotate(90, SLVec3f::AXISX);   // top
        else if (arucoIDs[i] == 5)
            faceViewMatrix.rotate(-90, SLVec3f::AXISX);  // bottom
        else
        {
            SL_LOG("ArUco cube: Invalid ID: %d", arucoIDs[i]);
            continue;
        }
 
        // Reset translation
        faceViewMatrix.m(12, translation.x);
        faceViewMatrix.m(13, translation.y);
        faceViewMatrix.m(14, translation.z);
 
        // Create a quaternion from the rotation of the matrix
        SLQuat4f rotation;
        rotation.fromMat3(faceViewMatrix.mat3());
 
        translations.emplace_back(translation.x, translation.y, translation.z);
        rotations.push_back(rotation);
        weights.push_back(weight);
    }
 
    //////////////////////////////////
    // AVERAGE FACE TRANSFORMATIONS //
    //////////////////////////////////
 
    if (!translations.empty())
    {
        // Average the translations and rotations
        CVVec3f  posNow = averageVector(translations, weights);
        SLQuat4f rotNow = averageQuaternion(rotations, weights);
 
        _averagePosition.set(posNow);
        _averageRotation.set(rotNow);
 
        CVVec3f  pos     = _averagePosition.average();
        SLQuat4f rotQuat = _averageRotation.average();
        SLMat3f  rot     = rotQuat.toMat3();
 
        // clang-format off
        // Convert to an OpenCV matrix
        _objectViewMat = CVMatx44f(rot.m(0), rot.m(3), rot.m(6), pos.val[0],
                                   rot.m(1), rot.m(4), rot.m(7), pos.val[1],
                                   rot.m(2), rot.m(5), rot.m(8), pos.val[2],
                                   0, 0, 0, 1);
        // clang-format on
 
        return true;
    }
 
    return false;
}

Member Data Documentation

_averagePosition

Averaged<CVVec3f> CVTrackedArucoCube::_averagePosition

private

Definition at line 109 of file CVTrackedArucoCube.h.

_averageRotation

AveragedQuat4f CVTrackedArucoCube::_averageRotation

private

Definition at line 110 of file CVTrackedArucoCube.h.

_edgeLength

float CVTrackedArucoCube::_edgeLength

private

Definition at line 107 of file CVTrackedArucoCube.h.

_roi

CVRect CVTrackedArucoCube::_roi = CVRect(0, 0, 0, 0)

Definition at line 113 of file CVTrackedArucoCube.h.

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

• CVTrackedArucoCube.h
• CVTrackedArucoCube.cpp