ilog.views.maps.srs.coordtrans
Class IlvFittedTransform

java.lang.Object
  ilog.views.maps.srs.coordtrans.IlvFittedTransform

All Implemented Interfaces:

IlvPersistentObject, IlvMathTransform

public class IlvFittedTransform
extends Object
implements IlvMathTransform, IlvPersistentObject

A transformation that transforms coordinates using a polynomial transform between two sets of points. The coefficients of the polynomial whose degree can be specified are computed using least square fitting algorithm. This transformation includes an optimization for polynomial of degree up to 4.

Since:

JViews 5.5

Constructor Summary

IlvFittedTransform(IlvCoordinate[] sourcePoints, IlvCoordinate[] destinationPoints, int degree)
Creates a new 2D polynomial transform.

IlvFittedTransform(IlvFittedTransform source)
Creates a new fitted transform which is a copy of the specified transformation.

IlvFittedTransform(IlvInputStream stream)
Reads an IlvFittedTransform from the specified input stream.

Method Summary

static IlvFittedTransform	CreateTransform(IlvCoordinate UL, IlvCoordinate LR, IlvCoordinateTransformation transform, int degree, double controlPointModifier) Creates an interpolation function for the specified coordinate transformation, for the area of interest which corners are specified.
Iterator	getDestinationPoints() Returns an iterator over the destination points.
IlvMathTransform	getInverse() Returns the inverse transformation of this transformation.
int	getSourceDimension() The dimension of source coordinates.
Iterator	getSourcePoints() Returns an iterator over the source points.
int	getTargetDimension() The dimension of target coordinates.
boolean	isIdentity() Returns true if this transformation is an identity.
IlvCoordinate[]	transform(IlvCoordinate[] sourceCP, IlvCoordinate[] targetCP) Transforms the specified array of points, and stores the result in the specified coordinate array.
IlvCoordinate	transform(IlvCoordinate sourceCP, IlvCoordinate targetCP) Transforms the specified source point, and stores the result in the specified coordinate.
void	write(IlvOutputStream stream) Writes this transformation to the specified output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvFittedTransform

public IlvFittedTransform(IlvCoordinate[] sourcePoints,
                          IlvCoordinate[] destinationPoints,
                          int degree)

Creates a new 2D polynomial transform. The number of points needed to find a polynomial of specified degree is (degree + 2)*(degree + 1)/2. For example:

• For a degree 1 polynomial (linear transformation) : 3 points.
• For a degree 2 polynomial : 6 points.
• For a degree 3 polynomial : 10 points.
• For a degree 4 polynomial : 15 points.

Parameters:

sourcePoints - The source points.

destinationPoints - The points to fit.

degree - The degree of the interpolation.

Throws:

IllegalArgumentException - If the number of points does not allow for a polynomial of degree degree to be found.

IlvFittedTransform

public IlvFittedTransform(IlvFittedTransform source)

Creates a new fitted transform which is a copy of the specified transformation.

Parameters:

source - The source transform

IlvFittedTransform

public IlvFittedTransform(IlvInputStream stream)
                   throws IlvReadFileException

Reads an IlvFittedTransform from the specified input stream.

Parameters:

stream - The IlvInputStream.

Throws:

IlvReadFileException - if the transformation cannot be read from the input stream.

Method Detail

write

public void write(IlvOutputStream stream)
           throws IOException

Writes this transformation to the specified output stream.

Specified by:

write in interface IlvPersistentObject

Parameters:

stream - The IlvOutputStream.

Throws:

Java.io.IOException - If an error occurs.

IOException - thrown when an exception occurs during the write operation for this object.

getSourceDimension

public int getSourceDimension()

The dimension of source coordinates.

Specified by:

getSourceDimension in interface IlvMathTransform

Returns:

2

getTargetDimension

public int getTargetDimension()

The dimension of target coordinates.

Specified by:

getTargetDimension in interface IlvMathTransform

Returns:

2

transform

public IlvCoordinate transform(IlvCoordinate sourceCP,
                               IlvCoordinate targetCP)
                        throws IlvCoordinateTransformationException

Transforms the specified source point, and stores the result in the specified coordinate. If the target coordinate is null, a new coordinate is created and returned.

Specified by:

transform in interface IlvMathTransform

Throws:

IlvCoordinateTransformationException

transform

public IlvCoordinate[] transform(IlvCoordinate[] sourceCP,
                                 IlvCoordinate[] targetCP)
                          throws IlvCoordinateTransformationException

Transforms the specified array of points, and stores the result in the specified coordinate array. If the target coordinate array is null, a new array of coordinates is created and returned.

Specified by:

transform in interface IlvMathTransform

Throws:

IlvCoordinateTransformationException

getInverse

public IlvMathTransform getInverse()

Returns the inverse transformation of this transformation.

Specified by:

getInverse in interface IlvMathTransform

isIdentity

public boolean isIdentity()

Returns true if this transformation is an identity.

Specified by:

isIdentity in interface IlvMathTransform

Returns:

true if this transformation is an identity.

getSourcePoints

public Iterator getSourcePoints()

Returns an iterator over the source points. Each individual source point can be retrieved by the following code:

IlvCoordinate[] sources = new IlvCoordinate[numPoints];
        IlvCoordinate[] dest = new IlvCoordinate[numPoints];

 for (Iterator i = transform.getSourcePoints(); i.hasNext() ; ) {
    IlvCoordinate c = (IlvCoordinate)i.next();
 }
 

Returns:

An iterator over the source points.

getDestinationPoints

public Iterator getDestinationPoints()

Returns an iterator over the destination points. Each individual destination point can be retrieved by the following code:

 for (Iterator i = transform.getDestinationPoints(); i.hasNext() ; ) {
    IlvCoordinate c = (IlvCoordinate)i.next();
 }
 

Returns:

An iterator over the destination points.

CreateTransform

public static IlvFittedTransform CreateTransform(IlvCoordinate UL,
                                                 IlvCoordinate LR,
                                                 IlvCoordinateTransformation transform,
                                                 int degree,
                                                 double controlPointModifier)
                                          throws IlvCoordinateTransformationException

Creates an interpolation function for the specified coordinate transformation, for the area of interest which corners are specified. The controlPointModifier parameter allows to specify a modifier to the number of points for the specified degree (example, 1.20 means use 20% more points that the theoretical number of points needed for a polynomial of degree degree).

Parameters:

UL - The upper left coordinate of the area of interest, expressed in the source coordinate system.

LR - The lower right coordinate of the area of interest, expressed in the source coordinate system.

transform - The transformation to interpolate.

degree - The degree of the interpolation function.

controlPointModifier - The modifier to the number of control points used. This must be greater than 1.

Returns:

The interpolation transform.

Throws:

IlvCoordinateTransformationException - if some points could not be transformed.