lti::hessianFunctor Class Reference

The hessianFunctor calculates three channels from an input channel L:. More...

#include <ltiHessianFunctor.h>

Inheritance diagram for lti::hessianFunctor:

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Collaboration diagram for lti::hessianFunctor:

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List of all members.

Classes
class	parameters
	The parameters for the class hessianFunctor. More...
Public Member Functions
	hessianFunctor ()
	hessianFunctor (const parameters &par)
	hessianFunctor (const hessianFunctor &other)
virtual	~hessianFunctor ()
virtual const char *	getTypeName () const
bool	apply (const channel &src, channel &xx, channel &xy, channel &yy) const
bool	apply (const channel8 &src, channel &xx, channel &xy, channel &yy) const
hessianFunctor &	copy (const hessianFunctor &other)
hessianFunctor &	operator= (const hessianFunctor &other)
virtual functor *	clone () const
const parameters &	getParameters () const
virtual bool	updateParameters ()
Protected Member Functions
bool	classicHessian (const channel &src, channel &xx, channel &xy, channel &yy) const
bool	classicXY (const channel &src, channel &xy) const
Protected Attributes
convolution	convXX
convolution	convYY
convolution	convXY

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Detailed Description

The hessianFunctor calculates three channels from an input channel L:.

Lxx, Lxy and Lyy which are the second derivative channels.

The make up the Hessian of each pixel of L like this:

/ Lxx(i,j) Lxy(i,j) \ H(i,j)= | | \ Lxy(i,j) Lyy(i,j) /

See parameters::eKernelType for available kernels.

Corresponding gradient kernels can be found in ltiGradientKernels.h

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Constructor & Destructor Documentation

lti::hessianFunctor::hessianFunctor

(

)

Default constructor.

lti::hessianFunctor::hessianFunctor

(

const parameters &

par

)

Construct a functor using the given parameters.

lti::hessianFunctor::hessianFunctor

(

const hessianFunctor &

other

)

Copy constructor.

Parameters:

other

the object to be copied

virtual lti::hessianFunctor::~hessianFunctor

(

)

[virtual]

Destructor.

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Member Function Documentation

bool lti::hessianFunctor::apply	(	const channel8 &	src,
		channel &	xx,
		channel &	xy,
		channel &	yy
	)			const

Calculated the second derivatives of the given channel8 which together form the components of the Hessian matrix of each pixel.

Note that the channel8 is converted to a channel before calculation.

Parameters:

	src	channel8 with the source data.
	xx	second derivative in xx direction.
	xy	second derivative in xy direction.
	yy	second derivative in yy direction.

Returns:

true if apply successful or false otherwise.

bool lti::hessianFunctor::apply	(	const channel &	src,
		channel &	xx,
		channel &	xy,
		channel &	yy
	)			const

Calculated the second derivatives of the given channel which together form the components of the Hessian matrix of each pixel.

Parameters:

	src	channel with the source data.
	xx	second derivative in xx direction.
	xy	second derivative in xy direction.
	yy	second derivative in yy direction.

Returns:

true if apply successful or false otherwise.

bool lti::hessianFunctor::classicHessian	(	const channel &	src,
		channel &	xx,
		channel &	xy,
		channel &	yy
	)			const [protected]

Fast calculation of the Hessian with classic kernels [1 -2 1] for XX and YY and [1 0 -1; 0 0 0; -1 0 1] for XY.

bool lti::hessianFunctor::classicXY	(	const channel &	src,
		channel &	xy
	)			const [protected]

Fast computation of the second derivative in XY direction using the kernel:.

  1  0 -1
  0  0  0
 -1  0  1

This is used for parameters::Hessian since it is much faster than convolution with a very sparse kernel.

virtual functor* lti::hessianFunctor::clone

(

)

const [virtual]

Returns a pointer to a clone of this functor.

Implements lti::functor.

hessianFunctor& lti::hessianFunctor::copy

(

const hessianFunctor &

other

)

Copy data of "other" functor.

Parameters:

other

the functor to be copied

Returns:

a reference to this functor object

Reimplemented from lti::functor.

const parameters& lti::hessianFunctor::getParameters

(

)

const

Returns used parameters.

Reimplemented from lti::transform.

virtual const char* lti::hessianFunctor::getTypeName

(

)

const [virtual]

Returns the name of this type ("hessianFunctor").

Reimplemented from lti::transform.

hessianFunctor& lti::hessianFunctor::operator=

(

const hessianFunctor &

other

)

Alias for copy member.

Parameters:

other

the functor to be copied

Returns:

a reference to this functor object

Reimplemented from lti::functor.

virtual bool lti::hessianFunctor::updateParameters

(

)

[virtual]

Set parameters.

Especially, set the correct kernels.

Reimplemented from lti::functor.

---

Member Data Documentation

convolution lti::hessianFunctor::convXX [protected]

Used for convolution in x or xx direction.

convolution lti::hessianFunctor::convXY [protected]

Used for convolution in xy direction.

convolution lti::hessianFunctor::convYY [protected]

Used for convolution in y or yy direction.

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

• ltiHessianFunctor.h