Utility class that provides functions to perspectively map 4 points of a source frame into 4 points of a destination frame. More...

#include <Projective4PointTransform.h>

Public Member Functions
	Projective4PointTransform ()
	creates an empty ID-transform More...

	Projective4PointTransform (const utils::Point32f srcQuad[4], const utils::Point32f dstQuad[4])
	creates a Projective4PointTransform instance with given src and dst quadrangle More...

	Projective4PointTransform (const std::vector< utils::Point32f > &srcQuad, const std::vector< utils::Point32f > dstQuad)
	creates a Projective4PointTransform instance with given src and dst quadrangle (vector version) More...

	Projective4PointTransform (const Mat3 &C)
	creates a Projective4PointTransform instance directly from a given 3by3 projective transform More...

void	init (const utils::Point32f srcQuad[4], const utils::Point32f dstQuad[4])
	intializes the Projective4PointTransform from given source and destination quadrangle More...

void	init (const utils::Rect32f &srcRect, const utils::Rect32f &dstRect=utils::Rect32f::null)
	intializes the Projective4PointTransform from given source and destination rectangles More...

void	init (const utils::Rect &srcRect, const utils::Rect &dstRect=utils::Rect::null)
	intializes the Projective4PointTransform from given source and destination rectangles (int-version) More...

const Mat3 &	getAInv () const
	returns the internally stored inverse source transform matrix More...

const Mat3 &	getB () const
	returns the internally stored inverse destination transform matrix More...

const Mat3 &	getC () const
	returns the internally stored combined transform matrix More...

std::vector< utils::Point32f >	getSrcQuad () const
	returns a copy of the internally held source quadrangle More...

std::vector< utils::Point32f >	getDstQuad () const
	returns a copy of the internally held destiation quadrangle More...

utils::Point32f	mapPoint (const utils::Point32f &p) const
	maps a single point from the source quadrangle into the destination quadrangle More...

void	setSrcQuad (const utils::Point32f srcQuad[4])
	updates the source quad (the other transforms are automatically updated) More...

void	setDstQuad (const utils::Point32f dstQuad[4])
	updates the destination quad (the other transforms are automatically updated) More...

void	setSrcQuad (const utils::Point32f &a, const utils::Point32f &b, const utils::Point32f &c, const utils::Point32f &d)
	updates the source quad (the other transforms are automatically updated, point-version) More...

void	setDstQuad (const utils::Point32f &a, const utils::Point32f &b, const utils::Point32f &c, const utils::Point32f &d)
	updates the destination quad (the other transforms are automatically updated, point-version) More...

std::vector< utils::Point32f >	map (const std::vector< utils::Point32f > &src)
	maps a whole set of points at once More...

template<class SrcForwardIterator , class DstForwardIterator >
void	map (SrcForwardIterator begin, SrcForwardIterator end, DstForwardIterator dst)
	maps points in an iterator based fashion More...

Private Attributes
Mat3	m_Ainv
	internally held inverse source transform More...

Mat3	m_B
	internally held destination transform More...

Mat3	m_C
	internally held result-transform C = B * A_inv More...

utils::Point32f	m_srcQuad [4]

utils::Point32f	m_dstQuad [4]
	source and destination quadrangles More...

Detailed Description

Utility class that provides functions to perspectively map 4 points of a source frame into 4 points of a destination frame.

In contrast to a standard bilinear interpolation, a 4-point projective transform also implements perspective vanishing point effencts. The algorithm was explained well in

http://math.stackexchange.com/questions/296794/finding-the-transform-matrix-from-4-projected-points-with-javascript

Constructor & Destructor Documentation

◆ Projective4PointTransform() [1/4]

icl::math::Projective4PointTransform::Projective4PointTransform ( )

creates an empty ID-transform

◆ Projective4PointTransform() [2/4]

icl::math::Projective4PointTransform::Projective4PointTransform	(	const utils::Point32f	srcQuad[4],
		const utils::Point32f	dstQuad[4]
	)

creates a Projective4PointTransform instance with given src and dst quadrangle

◆ Projective4PointTransform() [3/4]

icl::math::Projective4PointTransform::Projective4PointTransform	(	const std::vector< utils::Point32f > &	srcQuad,
		const std::vector< utils::Point32f >	dstQuad
	)

creates a Projective4PointTransform instance with given src and dst quadrangle (vector version)

◆ Projective4PointTransform() [4/4]

icl::math::Projective4PointTransform::Projective4PointTransform ( const Mat3 & C )

creates a Projective4PointTransform instance directly from a given 3by3 projective transform

In this case the intenally held source and destination quadrangles as well as the matrices Ainv and B will not be initialized

Member Function Documentation

◆ getAInv()

const Mat3& icl::math::Projective4PointTransform::getAInv ( ) const

inline

returns the internally stored inverse source transform matrix

◆ getB()

const Mat3& icl::math::Projective4PointTransform::getB ( ) const

inline

returns the internally stored inverse destination transform matrix

◆ getC()

const Mat3& icl::math::Projective4PointTransform::getC ( ) const

inline

returns the internally stored combined transform matrix

The actual point mapping of a point p = (x,y) is performed by homogenize( C * (x,y,1) ), where homogenize(x,y,k) = (x/k,y/k)

◆ getDstQuad()

std::vector<utils::Point32f> icl::math::Projective4PointTransform::getDstQuad ( ) const

returns a copy of the internally held destiation quadrangle

◆ getSrcQuad()

std::vector<utils::Point32f> icl::math::Projective4PointTransform::getSrcQuad ( ) const

returns a copy of the internally held source quadrangle

◆ init() [1/3]

void icl::math::Projective4PointTransform::init	(	const utils::Point32f	srcQuad[4],
		const utils::Point32f	dstQuad[4]
	)

intializes the Projective4PointTransform from given source and destination quadrangle

if either sourceQuad or destinationQuad is null, the internally held-quadrangles will be used instead. This allows this function to be used for updating the source or the destination quadrangle separately, if needed.

◆ init() [2/3]

void icl::math::Projective4PointTransform::init	(	const utils::Rect32f &	srcRect,
		const utils::Rect32f &	dstRect = `utils::Rect32f::null`
	)

intializes the Projective4PointTransform from given source and destination rectangles

For simplicity, also rectangular source and destination quadrangles can be used The default/null arguments Rect32f::null (for either srcRect or dstRect) are internally replaced with the current rectangles. By these means also srcRect or dstRect can also be updated separetely

◆ init() [3/3]

void icl::math::Projective4PointTransform::init	(	const utils::Rect &	srcRect,
		const utils::Rect &	dstRect = `utils::Rect::null`
	)

intializes the Projective4PointTransform from given source and destination rectangles (int-version)

See also: Projective4PointTransform::init(const utils::Rect32f &, const utils::Rect32f &)

◆ map() [1/2]

std::vector<utils::Point32f> icl::math::Projective4PointTransform::map ( const std::vector< utils::Point32f > & src )

maps a whole set of points at once

Please note that this is not more efficient then mapping all manually in a loop

◆ map() [2/2]

template<class SrcForwardIterator , class DstForwardIterator >

void icl::math::Projective4PointTransform::map	(	SrcForwardIterator	begin,
		SrcForwardIterator	end,
		DstForwardIterator	dst
	)

inline

maps points in an iterator based fashion

◆ mapPoint()

utils::Point32f icl::math::Projective4PointTransform::mapPoint ( const utils::Point32f & p ) const

inline

maps a single point from the source quadrangle into the destination quadrangle

◆ setDstQuad() [1/2]

void icl::math::Projective4PointTransform::setDstQuad ( const utils::Point32f dstQuad[4] )

updates the destination quad (the other transforms are automatically updated)

◆ setDstQuad() [2/2]

void icl::math::Projective4PointTransform::setDstQuad	(	const utils::Point32f &	a,
		const utils::Point32f &	b,
		const utils::Point32f &	c,
		const utils::Point32f &	d
	)

updates the destination quad (the other transforms are automatically updated, point-version)

◆ setSrcQuad() [1/2]

void icl::math::Projective4PointTransform::setSrcQuad ( const utils::Point32f srcQuad[4] )

updates the source quad (the other transforms are automatically updated)

◆ setSrcQuad() [2/2]

void icl::math::Projective4PointTransform::setSrcQuad	(	const utils::Point32f &	a,
		const utils::Point32f &	b,
		const utils::Point32f &	c,
		const utils::Point32f &	d
	)

updates the source quad (the other transforms are automatically updated, point-version)

Member Data Documentation

◆ m_Ainv

Mat3 icl::math::Projective4PointTransform::m_Ainv

private

internally held inverse source transform

◆ m_B

Mat3 icl::math::Projective4PointTransform::m_B

private

internally held destination transform

◆ m_C

Mat3 icl::math::Projective4PointTransform::m_C

private

internally held result-transform C = B * A_inv

◆ m_dstQuad

utils::Point32f icl::math::Projective4PointTransform::m_dstQuad[4]

private

source and destination quadrangles

◆ m_srcQuad

utils::Point32f icl::math::Projective4PointTransform::m_srcQuad[4]

private

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

/Users/alneuman/vm/icl/ICLMath/src/ICLMath/Projective4PointTransform.h

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Projective4PointTransform() [1/4]

◆ Projective4PointTransform() [2/4]

◆ Projective4PointTransform() [3/4]

◆ Projective4PointTransform() [4/4]

Member Function Documentation

◆ getAInv()

◆ getB()

◆ getC()

◆ getDstQuad()

◆ getSrcQuad()

◆ init() [1/3]

◆ init() [2/3]

◆ init() [3/3]

◆ map() [1/2]

◆ map() [2/2]

◆ mapPoint()

◆ setDstQuad() [1/2]

◆ setDstQuad() [2/2]

◆ setSrcQuad() [1/2]

◆ setSrcQuad() [2/2]

Member Data Documentation

◆ m_Ainv

◆ m_B

◆ m_C

◆ m_dstQuad

◆ m_srcQuad