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vtkEncodedGradientEstimator Class Reference

Superclass for gradient estimation. More...

#include <vtkEncodedGradientEstimator.h>

Inheritance diagram for vtkEncodedGradientEstimator:

[legend]Collaboration diagram for vtkEncodedGradientEstimator:

[legend]List of all members.

Public Methods
virtual const char *	GetClassName ()
virtual int	IsA (const char *type)
void	PrintSelf (ostream &os, vtkIndent index)
virtual void	SetInput (vtkImageData *)
virtual vtkImageData *	GetInput ()
virtual void	SetGradientMagnitudeScale (float)
virtual float	GetGradientMagnitudeScale ()
virtual void	SetGradientMagnitudeBias (float)
virtual float	GetGradientMagnitudeBias ()
virtual void	SetBoundsClip (int)
virtual int	GetBoundsClip ()
virtual void	BoundsClipOn ()
virtual void	BoundsClipOff ()
virtual void	SetBounds (int, int, int, int, int, int)
virtual void	SetBounds (int[6])
virtual int *	GetBounds ()
virtual void	GetBounds (int data[6])
void	Update (void)
unsigned short *	GetEncodedNormals (void)
int	GetEncodedNormalIndex (int xyz_index)
int	GetEncodedNormalIndex (int x_index, int y_index, int z_index)
unsigned char *	GetGradientMagnitudes (void)
virtual void	SetNumberOfThreads (int)
virtual int	GetNumberOfThreads ()
void	SetDirectionEncoder (vtkDirectionEncoder *direnc)
virtual vtkDirectionEncoder *	GetDirectionEncoder ()
virtual void	SetComputeGradientMagnitudes (int)
virtual int	GetComputeGradientMagnitudes ()
virtual void	ComputeGradientMagnitudesOn ()
virtual void	ComputeGradientMagnitudesOff ()
virtual void	SetCylinderClip (int)
virtual int	GetCylinderClip ()
virtual void	CylinderClipOn ()
virtual void	CylinderClipOff ()
virtual float	GetLastUpdateTimeInSeconds ()
virtual float	GetLastUpdateTimeInCPUSeconds ()
virtual int	GetUseCylinderClip ()
int *	GetCircleLimits ()
void	SetZeroNormalThreshold (float v)
virtual float	GetZeroNormalThreshold ()
virtual void	SetZeroPad (int)
virtual int	GetZeroPad ()
virtual void	ZeroPadOn ()
virtual void	ZeroPadOff ()
virtual int *	GetInputSize ()
virtual void	GetInputSize (int data[3])
virtual float *	GetInputAspect ()
virtual void	GetInputAspect (float data[3])
Static Public Methods
int	IsTypeOf (const char *type)
vtkEncodedGradientEstimator *	SafeDownCast (vtkObject *o)
Public Attributes
vtkImageData *	Input
unsigned short *	EncodedNormals
int	EncodedNormalsSize [3]
unsigned char *	GradientMagnitudes
vtkTimeStamp	BuildTime
Protected Methods
	vtkEncodedGradientEstimator ()
	~vtkEncodedGradientEstimator ()
	vtkEncodedGradientEstimator (const vtkEncodedGradientEstimator &)
void	operator= (const vtkEncodedGradientEstimator &)
virtual void	UpdateNormals (void)=0
void	ComputeCircleLimits (int size)
Protected Attributes
int	NumberOfThreads
vtkMultiThreader *	Threader
vtkDirectionEncoder *	DirectionEncoder
float	GradientMagnitudeScale
float	GradientMagnitudeBias
float	LastUpdateTimeInSeconds
float	LastUpdateTimeInCPUSeconds
float	ZeroNormalThreshold
int	CylinderClip
int *	CircleLimits
int	CircleLimitsSize
int	UseCylinderClip
int	BoundsClip
int	Bounds [6]
int	InputSize [3]
float	InputAspect [3]
int	ComputeGradientMagnitudes
int	ZeroPad

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Detailed Description

Superclass for gradient estimation.

Date:

2000/12/10 20:08:36

Revision:

1.22

vtkEncodedGradientEstimator is an abstract superclass for gradient estimation. It takes a scalar input of vtkImageData, computes a gradient value for every point, and encodes this value into a three byte value (2 for direction, 1 for magnitude) using the vtkDirectionEncoder. The direction encoder is defaulted to a vtkRecursiveSphereDirectionEncoder, but can be overridden with the SetDirectionEncoder method. The scale and the bias values for the gradient magnitude are used to convert it into a one byte value according to v = m*scale + bias where m is the magnitude and v is the resulting one byte value.

See also:

vtkFiniteDifferenceGradientEstimator vtkDirectionEncoder

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Member Function Documentation

virtual const char* vtkEncodedGradientEstimator::GetClassName (    )  [virtual]

Return the class name as a string. This method is defined in all subclasses of vtkObject with the vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject. Reimplemented in vtkFiniteDifferenceGradientEstimator.

int vtkEncodedGradientEstimator::GetEncodedNormalIndex (  int    xyz_index )

Get the encoded normal at an x,y,z location in the volume

unsigned short* vtkEncodedGradientEstimator::GetEncodedNormals (  void    )

Get the encoded normals.

unsigned char* vtkEncodedGradientEstimator::GetGradientMagnitudes (  void    )

Get the gradient magnitudes

virtual float vtkEncodedGradientEstimator::GetLastUpdateTimeInSeconds (    )  [virtual]

Get the time required for the last update in seconds or cpu seconds

virtual int vtkEncodedGradientEstimator::IsA (  const char *    type )  [virtual]

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject. Reimplemented in vtkFiniteDifferenceGradientEstimator.

int vtkEncodedGradientEstimator::IsTypeOf (  const char *    type )  [static]

Return 1 if this class type is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject. Reimplemented in vtkFiniteDifferenceGradientEstimator.

void vtkEncodedGradientEstimator::PrintSelf (  ostream &    os, vtkIndent    index )  [virtual]

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes. Reimplemented from vtkObject. Reimplemented in vtkFiniteDifferenceGradientEstimator.

vtkEncodedGradientEstimator* vtkEncodedGradientEstimator::SafeDownCast (  vtkObject *    o )  [static]

Will cast the supplied object to vtkObject* is this is a safe operation (i.e., a safe downcast); otherwise NULL is returned. This method is defined in all subclasses of vtkObject with the vtkTypeMacro found in vtkSetGet.h. Reimplemented from vtkObject. Reimplemented in vtkFiniteDifferenceGradientEstimator.

virtual void vtkEncodedGradientEstimator::SetBounds (  int   , int   , int   , int   , int   , int    )  [virtual]

Set / Get the bounds of the computation (used if this->ComputationBounds is 1.) The bounds are specified xmin, xmax, ymin, ymax, zmin, zmax.

virtual void vtkEncodedGradientEstimator::SetBoundsClip (  int    )  [virtual]

Turn on / off the bounding of the normal computation by the this->Bounds bounding box

virtual void vtkEncodedGradientEstimator::SetComputeGradientMagnitudes (  int    )  [virtual]

If you don't want to compute gradient magnitudes (but you do want normals for shading) this can be used. Be careful - if if you a non-constant gradient magnitude transfer function and you turn this on, it may crash

virtual void vtkEncodedGradientEstimator::SetCylinderClip (  int    )  [virtual]

If the data in each slice is only contained within a circle circumscribed within the slice, and the slice is square, then don't compute anything outside the circle. This circle through the slices forms a cylinder.

void vtkEncodedGradientEstimator::SetDirectionEncoder (  vtkDirectionEncoder *    direnc )

Set / Get the direction encoder used to encode normal directions to fit within two bytes

virtual void vtkEncodedGradientEstimator::SetGradientMagnitudeScale (  float    )  [virtual]

Set/Get the scale and bias for the gradient magnitude

virtual void vtkEncodedGradientEstimator::SetInput (  vtkImageData *    )  [virtual]

Set/Get the scalar input for which the normals will be calculated

virtual void vtkEncodedGradientEstimator::SetNumberOfThreads (  int    )  [virtual]

Get/Set the number of threads to create when encoding normals This defaults to the number of available processors on the machine

void vtkEncodedGradientEstimator::SetZeroNormalThreshold (  float    v )

Set / Get the ZeroNormalThreshold - this defines the minimum magnitude of a gradient that is considered sufficient to define a direction. Gradients with magnitudes at or less than this value are given a "zero normal" index. These are handled specially in the shader, and you can set the intensity of light for these zero normals in the gradient shader.

virtual void vtkEncodedGradientEstimator::SetZeroPad (  int    )  [virtual]

Assume that the data value outside the volume is zero when computing normals.

void vtkEncodedGradientEstimator::Update (  void    )

Recompute the encoded normals and gradient magnitudes.

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

• vtkEncodedGradientEstimator.h

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