Class implementing 2D linear transformation. More...

#include <LinearTransformation.h>

Inheritance diagram for eLynx::Math::LinearTransformation:

Public Member Functions
	LinearTransformation ()
	Constructor, creates identity transformation.
	LinearTransformation (const LinearTransformation &c)
	Copy constructor.
LinearTransformation &	operator= (const LinearTransformation &c)
	An assignement operator.
virtual boost::shared_ptr < AbstractTransformation >	Clone () const
	Creates and returns copy of this object.
double	GetValue (uint32 iRow, uint32 iCol) const
	Returns specified value of the transformation matrix.
void	SetValue (uint32 iRow, uint32 iCol, double iValue)
	Sets specified value of the transformation matrix.
LinearTransformation &	NullTransformation ()
	Sets transformation to null transformation and returns this object.
LinearTransformation &	Identity ()
	Sets transformation to identity and returns this object.
virtual bool	IsIdentity () const
	Returns true, if actual transformation is identity.
LinearTransformation &	Translation (double iDX, double iDY)
	Sets transformation to translation and returns this object.
LinearTransformation &	Rotation (double iAngle)
	Sets transformation to rotation and returns this object.
LinearTransformation &	Scale (double iSX, double iSY)
	Sets transformation to scaling and returns this object.
LinearTransformation &	GeneralTransformation (double iA, double iB, double iC, double iD, double iE, double iF)
	Sets transformation to general linear transformation: x' = Ax+By+C y' = Dx+Ey+F and returns this object.
LinearTransformation &	Multiply (const LinearTransformation &iTrf)
	Multiplies current matrix with given matrix, storing the result in current object and returning it (behaves like *= operator).
LinearTransformation &	Inverse (const LinearTransformation &iTrf)
	Sets transformation to inverse of specified transformation.
virtual void	Transform (double iX, double iY, double &oX, double &oY) const
	Abstract method, which transforms position of the pixel in the coordinate space of the first image, into position in the coordinate space of the second image.
virtual void	GetTransformedBBox (uint32 iWidth, uint32 iHeight, double &oLeft, double &oTop, double &oWidth, double &oHeight) const
	Abstract method, which computes bounding box of the transformed (second) image in the coordinate space of the first image.
virtual void	InverseTransform (double iX, double iY, double &oX, double &oY) const
	Abstract method, which transforms position of the pixel in the coordinate space of the second image, into position in the coordinate space of the first image.
virtual void	GetInverseBBox (uint32 iWidth, uint32 iHeight, double &oLeft, double &oTop, double &oWidth, double &oHeight) const
	Abstract method, which computes bounding box of the original (first) image in the coordinate space of the second image.

Detailed Description

Class implementing 2D linear transformation.

Transformation is (as usual) represented by 3x3 matrix. Class provides methods to set typical transformations like translation, rotation or scaling. Also, it provides a method to combine transformations by matrix multiplication.

Constructor & Destructor Documentation

eLynx::Math::LinearTransformation::LinearTransformation ( const LinearTransformation & c )

Copy constructor.

Parameters:

c	the object to be copied

Member Function Documentation

virtual boost::shared_ptr<AbstractTransformation> eLynx::Math::LinearTransformation::Clone ( ) const [virtual]

Creates and returns copy of this object.

Returns:: the copy of this object

Implements eLynx::Math::AbstractTransformation.

LinearTransformation& eLynx::Math::LinearTransformation::GeneralTransformation	(	double	iA,
		double	iB,
		double	iC,
		double	iD,
		double	iE,
		double	iF
	)

Sets transformation to general linear transformation: x' = A*x+B*y+C y' = D*x+E*y+F and returns this object.

Parameters:

iA	the (0,0) matrix coefficient
iB	the (1,0) matrix coefficient
iC	the (2,0) matrix coefficient
iD	the (0,1) matrix coefficient
iE	the (1,1) matrix coefficient
iF	the (2,1) matrix coefficient

Returns:: reference to this object

virtual void eLynx::Math::LinearTransformation::GetInverseBBox	(	uint32	iWidth,
		uint32	iHeight,
		double &	oLeft,
		double &	oTop,
		double &	oWidth,
		double &	oHeight
	)		const `[virtual]`

Abstract method, which computes bounding box of the original (first) image in the coordinate space of the second image.

Second image has a bounding box (0, 0)-(iWidth, iHeight). First image has a bounding box (oLeft, oTop)-(oLeft+oWidth, oTop+oHeight).

Parameters:

iWidth	the width of the second image
iHeight	the height of the second image
oLeft	the left coordinate of the first image bounding box
oTop	the top coordinate of the first image bounding box
oWidth	the width of the first image bounding box
oHeight	the height of the first image bounding box

Implements eLynx::Math::AbstractTransformation.

virtual void eLynx::Math::LinearTransformation::GetTransformedBBox	(	uint32	iWidth,
		uint32	iHeight,
		double &	oLeft,
		double &	oTop,
		double &	oWidth,
		double &	oHeight
	)		const `[virtual]`

Abstract method, which computes bounding box of the transformed (second) image in the coordinate space of the first image.

First image has a bounding box (0, 0)-(iWidth, iHeight). Second image has a bounding box (oLeft, oTop)-(oLeft+oWidth, oTop+oHeight).

Parameters:

iWidth	the width of the first image
iHeight	the height of the first image
oLeft	the left coordinate of the second image bounding box
oTop	the top coordinate of the second image bounding box
oWidth	the width of the second image bounding box
oHeight	the height of the second image bounding box

Implements eLynx::Math::AbstractTransformation.

double eLynx::Math::LinearTransformation::GetValue	(	uint32	iRow,
		uint32	iCol
	)		const

Returns specified value of the transformation matrix.

Parameters:

iRow	the number of row (0..2)
iCol	the number of column (0..2)

Returns:: the matrix value

LinearTransformation& eLynx::Math::LinearTransformation::Identity ( )

Sets transformation to identity and returns this object.

Identity transforms all vectors to themselves.

Returns:: reference to this object.

LinearTransformation& eLynx::Math::LinearTransformation::Inverse ( const LinearTransformation & iTrf )

Sets transformation to inverse of specified transformation.

The transformation must be invertible - this means determinant of transformation matrix must be non-zero. If it is not, the exception is raised.

Parameters:

iTrf	the matrix to be inverted

Returns:: reference to this object (inverted matrix)

virtual void eLynx::Math::LinearTransformation::InverseTransform	(	double	iX,
		double	iY,
		double &	oX,
		double &	oY
	)		const `[virtual]`

Abstract method, which transforms position of the pixel in the coordinate space of the second image, into position in the coordinate space of the first image.

Parameters:

iX	the x coordinate of the pixel on the second image
iY	the y coordinate of the pixel on the second image
oX	the x position on the first image
oY	the y position on the first image

Implements eLynx::Math::AbstractTransformation.

virtual bool eLynx::Math::LinearTransformation::IsIdentity ( ) const [virtual]

Returns true, if actual transformation is identity.

Can be used to speed up the process (by not transforming at all).

Returns:: true for identity transformation, false otherwise.

Implements eLynx::Math::AbstractTransformation.

LinearTransformation& eLynx::Math::LinearTransformation::Multiply ( const LinearTransformation & iTrf )

Multiplies current matrix with given matrix, storing the result in current object and returning it (behaves like *= operator).

The matrix multiplication is equivalent to adding transformations.

Parameters:

iTrf	the matrix current matrix should be multiplied with

Returns:: reference to this object (result of multiplication this*iTrf)

LinearTransformation& eLynx::Math::LinearTransformation::NullTransformation ( )

Sets transformation to null transformation and returns this object.

Null transformation transforms all vectors to null vector.

Returns:: reference to this object

LinearTransformation& eLynx::Math::LinearTransformation::operator= ( const LinearTransformation & c )

An assignement operator.

Parameters:

c	the object to be copied

Returns:: the reference to this object

LinearTransformation& eLynx::Math::LinearTransformation::Rotation ( double iAngle )

Sets transformation to rotation and returns this object.

The rotation is performed around origin [0,0], counter-clockwise for positive angle.

Parameters:

iAngle the angle in radians.

Returns:: reference to this object

LinearTransformation& eLynx::Math::LinearTransformation::Scale	(	double	iSX,
		double	iSY
	)

Sets transformation to scaling and returns this object.

The scaling is performed with respect to origin [0, 0].

Parameters:

iSX	the scale factor in x direction
iSY	the scale factor in y direction

Returns:: reference to this object

void eLynx::Math::LinearTransformation::SetValue	(	uint32	iRow,
		uint32	iCol,
		double	iValue
	)

Sets specified value of the transformation matrix.

Parameters:

iRow	the number of row (0..2)
iCol	the number of column (0..2)
iValue	the value to be set

virtual void eLynx::Math::LinearTransformation::Transform	(	double	iX,
		double	iY,
		double &	oX,
		double &	oY
	)		const `[virtual]`

Abstract method, which transforms position of the pixel in the coordinate space of the first image, into position in the coordinate space of the second image.

Parameters:

iX	the x coordinate of the pixel on the first image
iY	the y coordinate of the pixel on the first image
oX	the x position on the second image
oY	the y position on the second image

Implements eLynx::Math::AbstractTransformation.

LinearTransformation& eLynx::Math::LinearTransformation::Translation	(	double	iDX,
		double	iDY
	)

Sets transformation to translation and returns this object.

Parameters:

iDX	the delta value in x direction
iDY	the delta value in y direction

Returns:: reference to this object

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

E:/dev/eLynx/include/elx/math/LinearTransformation.h

eLynx::Math::LinearTransformation Class Reference

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation