boofcv.alg.fiducial.square

Class QuadPoseEstimator

java.lang.Object

boofcv.alg.fiducial.square.QuadPoseEstimator

public class QuadPoseEstimator
extends java.lang.Object

Estimates the pose using P3P and iterative refinement from 4 points on a plane with known locations. While this seems like it would be a trivial problem it actually takes several techniques to ensure accurate results. At a high level it uses P3P to provide an estimate. If the error is large it then uses EPNP. Which ever is better it then refines. If the target is small and directly facing the camera it will enlarge the target to estimate it's orientation. Otherwise it will over fit location since it takes a large change in orientation to influence the result.

Field Summary

Fields

Modifier and Type	Field and Description
static double	FUDGE_FACTOR
static double	SMALL_PIXELS

Constructor Summary

Constructors

Constructor and Description
QuadPoseEstimator(double refineTol, int refineIterations) Constructor which picks reasonable and generally good algorithms for pose estimation.
QuadPoseEstimator(EstimateNofPnP p3p, RefinePnP refine) Constructor in which internal estimation algorithms are provided

Method Summary

Modifier and Type	Method and Description
double	getError() Reprojection error of fiducial
Se3_F64	getWorldToCamera()
boolean	process(Quadrilateral_F64 corners) Estimate the 3D pose of the camera from the observed location of the fiducial.
void	setFiducial(double x0, double y0, double x1, double y1, double x2, double y2, double x3, double y3) Specify the location of points on the 2D fiducial.
void	setIntrinsic(IntrinsicParameters intrinsic) Specifies the intrinsic parameters.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SMALL_PIXELS

public static final double SMALL_PIXELS

See Also:

Constant Field Values

FUDGE_FACTOR

public static final double FUDGE_FACTOR

See Also:

Constant Field Values

Constructor Detail

QuadPoseEstimator

public QuadPoseEstimator(double refineTol,
                         int refineIterations)

Constructor which picks reasonable and generally good algorithms for pose estimation.

Parameters:

refineTol - Convergence tolerance. Try 1e-8

refineIterations - Number of refinement iterations. Try 200

QuadPoseEstimator

public QuadPoseEstimator(EstimateNofPnP p3p,
                         RefinePnP refine)

Constructor in which internal estimation algorithms are provided

Method Detail

setIntrinsic

public void setIntrinsic(IntrinsicParameters intrinsic)

Specifies the intrinsic parameters.

Parameters:

intrinsic - Intrinsic camera parameters

setFiducial

public void setFiducial(double x0,
                        double y0,
                        double x1,
                        double y1,
                        double x2,
                        double y2,
                        double x3,
                        double y3)

Specify the location of points on the 2D fiducial.

process

public boolean process(Quadrilateral_F64 corners)

Estimate the 3D pose of the camera from the observed location of the fiducial.

MUST call setFiducial(double, double, double, double, double, double, double, double) and setIntrinsic(boofcv.struct.calib.IntrinsicParameters) before calling this function.

Parameters:

corners - Observed corners of fiducials which are in the same order as their 2D counter parts

Returns:

true if successful or false if not

getWorldToCamera

public Se3_F64 getWorldToCamera()

getError

public double getError()

Reprojection error of fiducial