org.openimaj.math.geometry.transforms

Class HomographyModel

java.lang.Object

org.openimaj.math.geometry.transforms.HomographyModel

All Implemented Interfaces:

Cloneable, MatrixTransformProvider, EstimatableModel<Point2d,Point2d>, Model<Point2d,Point2d>

public class HomographyModel
extends Object
implements EstimatableModel<Point2d,Point2d>, MatrixTransformProvider

Implementation of a Homogeneous Homography model - a transform that models the relationship between planes under projective constraints (8 D.o.F)

Author:

Jonathon Hare

Field Summary

Fields

Modifier and Type	Field and Description
protected Jama.Matrix	homography
protected Predicate<HomographyModel>	modelCheck
protected boolean	normalise

Constructor Summary

Constructors

Constructor and Description
HomographyModel() Create an HomographyModel that automatically normalises the data given to estimate(List) to get a numerically stable estimate.
HomographyModel(boolean norm) Create a HomographyModel with optional automatic normalisation.
HomographyModel(boolean norm, Predicate<HomographyModel> mc) Create a HomographyModel with optional automatic normalisation.
HomographyModel(Predicate<HomographyModel> mc) Create an HomographyModel that automatically normalises the data given to estimate(List) to get a numerically stable estimate.

Method Summary

Modifier and Type	Method and Description
HomographyModel	clone() Clone the model
void	denormaliseHomography(Pair<Jama.Matrix> normalisations) De-normalise a homography estimate.
boolean	estimate(List<? extends IndependentPair<Point2d,Point2d>> data) DLT estimation of least-squares solution of 3D homogeneous homography
Jama.Matrix	getTransform()
int	numItemsToEstimate()
Point2d	predict(Point2d data) Uses the model to predict dependent data from an independent value.
void	setTransform(Jama.Matrix matrix) Set the transform matrix to the new one

Methods inherited from class java.lang.Object

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

Field Detail

modelCheck

protected Predicate<HomographyModel> modelCheck

homography

protected Jama.Matrix homography

normalise

protected boolean normalise

Constructor Detail

HomographyModel

public HomographyModel()

Create an HomographyModel that automatically normalises the data given to estimate(List) to get a numerically stable estimate.

HomographyModel

public HomographyModel(boolean norm)

Create a HomographyModel with optional automatic normalisation.

Parameters:

norm - true if the data should be automatically normalised before running the DLT algorithm

HomographyModel

public HomographyModel(Predicate<HomographyModel> mc)

Create an HomographyModel that automatically normalises the data given to estimate(List) to get a numerically stable estimate. The given Predicate is used by the estimate(List) method to test whether the estimated homography is sensible.

Parameters:

mc - the test function for sensible homographies

HomographyModel

public HomographyModel(boolean norm,
                       Predicate<HomographyModel> mc)

Create a HomographyModel with optional automatic normalisation. The given Predicate is used by the estimate(List) method to test whether the estimated homography is sensible

Parameters:

norm - true if the data should be automatically normalised before running the DLT algorithm

mc - the test function for sensible homographies

Method Detail

clone

public HomographyModel clone()

Description copied from interface: EstimatableModel

Clone the model

Specified by:

clone in interface EstimatableModel<Point2d,Point2d>

Overrides:

clone in class Object

Returns:

a cloned copy

getTransform

public Jama.Matrix getTransform()

Specified by:

getTransform in interface MatrixTransformProvider

Returns:

the transform matrix represented by the object

setTransform

public void setTransform(Jama.Matrix matrix)

Set the transform matrix to the new one

Parameters:

matrix - the new matrix

estimate

public boolean estimate(List<? extends IndependentPair<Point2d,Point2d>> data)

DLT estimation of least-squares solution of 3D homogeneous homography

Specified by:

estimate in interface EstimatableModel<Point2d,Point2d>

Parameters:

data - Data with which to estimate the model

Returns:

true if a successful estimate was made, false otherwise

See Also:

EstimatableModel.estimate(java.util.List)

denormaliseHomography

public void denormaliseHomography(Pair<Jama.Matrix> normalisations)

De-normalise a homography estimate. Use when estimate(List) was called with pre-normalised data.

Parameters:

normalisations - the normalisation transforms

numItemsToEstimate

public int numItemsToEstimate()

Specified by:

numItemsToEstimate in interface EstimatableModel<Point2d,Point2d>

Returns:

The minimum number of observations required to estimate the model.

predict

public Point2d predict(Point2d data)

Description copied from interface: Model

Uses the model to predict dependent data from an independent value.

Specified by:

predict in interface Model<Point2d,Point2d>

Parameters:

data - the data (independent variable)

Returns:

Dependent variable(s) predicted from the independent ones.