Canny edge detector in 3D space. More...

#include <mdsCanny.h>

Inheritance diagram for mds::img::CVolumeCanny< V >:

Public Types
enum	{ TEMPLATE_PARAMETER_IS_NOT_VOLUME = V::CLASS_VOLUME }
	Check that V is a volume. More...
enum	{ BLOCK_SIZE = 128 }
	Size of the processing block (volume window). More...
typedef CVolumeEdgeDetector< V >	base
	Volume filter base.
typedef base::tVolume	tVolume
	Volume type.
typedef base::tVoxel	tVoxel
	Voxel type.
Public Member Functions
	CVolumeCanny (double dT1, double dT2)
	Default constructor.
void	getThresholds (double &dT1, double &dT2)
	Returns thresholds of the non-maximal suppression algorithm.
bool	operator() (const tVolume &SrcVolume, tVolume &DstVolume)
	Edge detection.
void	setThresholds (double dT1, double dT2)
	Sets thresholds of the non-maximal suppression algorithm.
	~CVolumeCanny ()
	Destructor.
Protected Member Functions
bool	checkNeighbours (tVolume &Volume, tSize x, tSize y, tSize z, tVoxel T)
	Returns true if any neighbouring voxel has greater value than a given threshold.
void	hysteresis (tVolume &MagnitudeVolume, tVolume &Volume, tSize x, tSize y, tSize z, tSize XSize, tSize YSize, tSize ZSize, tVoxel T1, tVoxel T2)
	Hystersis controlled by two given thresholds.
void	nonMaxSuppression (const tVolume &GradVolumeX, const tVolume &GradVolumeY, const tVolume &GradVolumeZ, tVolume &MagnitudeVolume, tVolume &Volume, tSize x, tSize y, tSize z, tSize XSize, tSize YSize, tSize ZSize)
	Non-maximal suppression.
Protected Attributes
double	m_dT1
	Thresholds used by hysteresis algorithm.
double	m_dT2
CVolumeGauss3Filter< tVolume >	m_GaussFilter
	Gaussian smoothing filter.
CVolumeSobelX< tVolume, CShiftZero2Gray >	m_SobelX
	Sobel operators.
CVolumeSobelY< tVolume, CShiftZero2Gray >	m_SobelY
CVolumeSobelZ< tVolume, CShiftZero2Gray >	m_SobelZ

Detailed Description

template<class V>
class mds::img::CVolumeCanny< V >

Canny edge detector in 3D space.

Parameter V is a used volume type.

Member Typedef Documentation

template<class V >

typedef CVolumeEdgeDetector<V> mds::img::CVolumeCanny< V >::base

Volume filter base.

template<class V >

typedef base::tVolume mds::img::CVolumeCanny< V >::tVolume

Volume type.

Reimplemented from mds::img::CVolumeEdgeDetector< V >.

template<class V >

typedef base::tVoxel mds::img::CVolumeCanny< V >::tVoxel

Voxel type.

Reimplemented from mds::img::CVolumeEdgeDetector< V >.

Member Enumeration Documentation

template<typename V >

anonymous enum [inherited]

Check that V is a volume.

You will see name of this enum somewhere in compiler error message if the type V is not volume.

Enumerator:

TEMPLATE_PARAMETER_IS_NOT_VOLUME

template<class V >

anonymous enum

Size of the processing block (volume window).

The input volume is divided into smaller blocks - cubes for the processing.

This is used to reduce amount of the memory required by the filtering.

Enumerator:

BLOCK_SIZE

Constructor & Destructor Documentation

template<class V >

mds::img::CVolumeCanny< V >::CVolumeCanny	(	double	dT1,
		double	dT2
	)

Default constructor.

Thresholds for the hysteresis (0..1).

template<class V >

mds::img::CVolumeCanny< V >::~CVolumeCanny ( )

Destructor.

Member Function Documentation

template<class V >

bool CVolumeCanny::checkNeighbours	(	tVolume &	Volume,
		tSize	x,
		tSize	y,
		tSize	z,
		tVoxel	T
	)		`[protected]`

Returns true if any neighbouring voxel has greater value than a given threshold.

template<class V >

void CVolumeCanny::getThresholds	(	double &	dT1,
		double &	dT2
	)

Returns thresholds of the non-maximal suppression algorithm.

template<class V >

void CVolumeCanny::hysteresis	(	tVolume &	MagnitudeVolume,
		tVolume &	Volume,
		tSize	x,
		tSize	y,
		tSize	z,
		tSize	XSize,
		tSize	YSize,
		tSize	ZSize,
		tVoxel	T1,
		tVoxel	T2
	)		`[protected]`

Hystersis controlled by two given thresholds.

Applies the hysteresis to the provided volume. It checks each voxel against an upper threshhold 'T1'. If the voxel value is equal or higher, the current voxel is an edge voxel. Then all direct neighbours of the voxel are compared to a lower threshhold 'T2' and if their values are equal or higher than this threshhold, they become edge voxels as well.
In practice the threshold T1 = (2-3) * T2.

template<class V >

void CVolumeCanny::nonMaxSuppression	(	const tVolume &	GradVolumeX,
		const tVolume &	GradVolumeY,
		const tVolume &	GradVolumeZ,
		tVolume &	MagnitudeVolume,
		tVolume &	Volume,
		tSize	x,
		tSize	y,
		tSize	z,
		tSize	XSize,
		tSize	YSize,
		tSize	ZSize
	)		`[protected]`