boofcv.alg.geo.calibration

Class Zhang99CalibrationMatrixFromHomographies

java.lang.Object

boofcv.alg.geo.calibration.Zhang99CalibrationMatrixFromHomographies

public class Zhang99CalibrationMatrixFromHomographies
extends java.lang.Object

Estimates camera calibration matrix from a set of homographies using linear algebra. Based upon the description found in [1], but has been modified to improve stability and flexibility. Two variants are implemented inside this class. One variant assumes that the skew is zero and requires two or more homographies and the other variant does not assume the skew is zero and requires three or more homographies. The calibration matrix structure is shown below.

Calibration matrix is defined as follows:
[ α c u₀ ]
[ 0 β v₀ ]
[ 0 0 1 ]
where 'c' is the camera's skew.

The zero skew variant is a modification of what was described in [1]. Instead of simply adding another row to force the skew to be zero that entire part of the equation has been omitted. The algorithm described in [1] was numerically unstable and did not produce meaningful results.

[1] Zhengyou Zhang, "Flexible Camera Calibration By Viewing a Plane From Unknown Orientations,", International Conference on Computer Vision (ICCV'99), Corfu, Greece, pages 666-673, September 1999.

Constructor Summary

Constructors

Constructor and Description
Zhang99CalibrationMatrixFromHomographies(boolean assumeZeroSkew) Configures calibration estimation.

Method Summary

Modifier and Type	Method and Description
org.ejml.data.DenseMatrix64F	getCalibrationMatrix() Returns the computed calibration matrix.
org.ejml.interfaces.decomposition.SingularValueDecomposition<org.ejml.data.DenseMatrix64F>	getSvd()
void	process(java.util.List<org.ejml.data.DenseMatrix64F> homographies) Given a set of homographies computed from a sequence of images that observe the same plane it estimates the camera's calibration.

Methods inherited from class java.lang.Object

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

Constructor Detail

Zhang99CalibrationMatrixFromHomographies

public Zhang99CalibrationMatrixFromHomographies(boolean assumeZeroSkew)

Configures calibration estimation.

Parameters:

assumeZeroSkew - Assume that skew matrix is zero or not

Method Detail

process

public void process(java.util.List<org.ejml.data.DenseMatrix64F> homographies)

Given a set of homographies computed from a sequence of images that observe the same plane it estimates the camera's calibration.

Parameters:

homographies - Homographies computed from observations of the calibration grid.

getCalibrationMatrix

public org.ejml.data.DenseMatrix64F getCalibrationMatrix()

Returns the computed calibration matrix.

Returns:

Calibration matrix.

getSvd

public org.ejml.interfaces.decomposition.SingularValueDecomposition<org.ejml.data.DenseMatrix64F> getSvd()