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vtkFiniteDifferenceGradientEstimator Class Reference

Use finite differences to estimate gradient. More...

#include <vtkFiniteDifferenceGradientEstimator.h>

Inheritance diagram for vtkFiniteDifferenceGradientEstimator:
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Collaboration diagram for vtkFiniteDifferenceGradientEstimator:
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Public Types

typedef vtkEncodedGradientEstimator Superclass
 
- Public Types inherited from vtkEncodedGradientEstimator
typedef vtkObject Superclass
 

Public Member Functions

virtual vtkTypeBool IsA (const char *type)
 Return 1 if this class is the same type of (or a subclass of) the named class. More...
 
vtkFiniteDifferenceGradientEstimatorNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
virtual void SetSampleSpacingInVoxels (int)
 Set/Get the spacing between samples for the finite differences method used to compute the normal. More...
 
virtual int GetSampleSpacingInVoxels ()
 
- Public Member Functions inherited from vtkEncodedGradientEstimator
vtkEncodedGradientEstimatorNewInstance () const
 
virtual void SetInputData (vtkImageData *)
 Set/Get the scalar input for which the normals will be calculated. More...
 
virtual vtkImageDataGetInputData ()
 
virtual void SetGradientMagnitudeScale (float)
 Set/Get the scale and bias for the gradient magnitude. More...
 
virtual float GetGradientMagnitudeScale ()
 
virtual void SetGradientMagnitudeBias (float)
 
virtual float GetGradientMagnitudeBias ()
 
virtual void SetBoundsClip (vtkTypeBool)
 Turn on / off the bounding of the normal computation by the this->Bounds bounding box. More...
 
virtual vtkTypeBool GetBoundsClip ()
 
virtual void BoundsClipOn ()
 
virtual void BoundsClipOff ()
 
virtual void SetBounds (int, int, int, int, int, int)
 Set / Get the bounds of the computation (used if this->ComputationBounds is 1.) The bounds are specified xmin, xmax, ymin, ymax, zmin, zmax. More...
 
virtual void SetBounds (int[6])
 
virtual int * GetBounds ()
 
virtual void GetBounds (int data[6])
 
void Update (void)
 Recompute the encoded normals and gradient magnitudes. More...
 
unsigned short * GetEncodedNormals (void)
 Get the encoded normals. More...
 
int GetEncodedNormalIndex (vtkIdType xyz_index)
 Get the encoded normal at an x,y,z location in the volume. More...
 
int GetEncodedNormalIndex (int x_index, int y_index, int z_index)
 
unsigned char * GetGradientMagnitudes (void)
 Get the gradient magnitudes. More...
 
virtual void SetNumberOfThreads (int)
 Get/Set the number of threads to create when encoding normals This defaults to the number of available processors on the machine. More...
 
virtual int GetNumberOfThreads ()
 
void SetDirectionEncoder (vtkDirectionEncoder *direnc)
 Set / Get the direction encoder used to encode normal directions to fit within two bytes. More...
 
virtual vtkDirectionEncoderGetDirectionEncoder ()
 
virtual void SetComputeGradientMagnitudes (vtkTypeBool)
 If you don't want to compute gradient magnitudes (but you do want normals for shading) this can be used. More...
 
virtual vtkTypeBool GetComputeGradientMagnitudes ()
 
virtual void ComputeGradientMagnitudesOn ()
 
virtual void ComputeGradientMagnitudesOff ()
 
virtual void SetCylinderClip (vtkTypeBool)
 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. More...
 
virtual vtkTypeBool GetCylinderClip ()
 
virtual void CylinderClipOn ()
 
virtual void CylinderClipOff ()
 
virtual float GetLastUpdateTimeInSeconds ()
 Get the time required for the last update in seconds or cpu seconds. More...
 
virtual float GetLastUpdateTimeInCPUSeconds ()
 
virtual int GetUseCylinderClip ()
 
int * GetCircleLimits ()
 
void SetZeroNormalThreshold (float v)
 Set / Get the ZeroNormalThreshold - this defines the minimum magnitude of a gradient that is considered sufficient to define a direction. More...
 
virtual float GetZeroNormalThreshold ()
 
virtual void SetZeroPad (vtkTypeBool)
 Assume that the data value outside the volume is zero when computing normals. More...
 
virtual vtkTypeBool 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])
 
- Public Member Functions inherited from vtkObject
 vtkBaseTypeMacro (vtkObject, vtkObjectBase)
 
virtual void DebugOn ()
 Turn debugging output on. More...
 
virtual void DebugOff ()
 Turn debugging output off. More...
 
bool GetDebug ()
 Get the value of the debug flag. More...
 
void SetDebug (bool debugFlag)
 Set the value of the debug flag. More...
 
virtual void Modified ()
 Update the modification time for this object. More...
 
virtual vtkMTimeType GetMTime ()
 Return this object's modified time. More...
 
unsigned long AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
unsigned long AddObserver (const char *event, vtkCommand *, float priority=0.0f)
 
vtkCommandGetCommand (unsigned long tag)
 
void RemoveObserver (vtkCommand *)
 
void RemoveObservers (unsigned long event, vtkCommand *)
 
void RemoveObservers (const char *event, vtkCommand *)
 
vtkTypeBool HasObserver (unsigned long event, vtkCommand *)
 
vtkTypeBool HasObserver (const char *event, vtkCommand *)
 
void RemoveObserver (unsigned long tag)
 
void RemoveObservers (unsigned long event)
 
void RemoveObservers (const char *event)
 
void RemoveAllObservers ()
 
vtkTypeBool HasObserver (unsigned long event)
 
vtkTypeBool HasObserver (const char *event)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
 Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, bool(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 Allow user to set the AbortFlagOn() with the return value of the callback method. More...
 
int InvokeEvent (unsigned long event, void *callData)
 This method invokes an event and return whether the event was aborted or not. More...
 
int InvokeEvent (const char *event, void *callData)
 
int InvokeEvent (unsigned long event)
 
int InvokeEvent (const char *event)
 
- Public Member Functions inherited from vtkObjectBase
const char * GetClassName () const
 Return the class name as a string. More...
 
virtual void Delete ()
 Delete a VTK object. More...
 
virtual void FastDelete ()
 Delete a reference to this object. More...
 
void InitializeObjectBase ()
 
void Print (ostream &os)
 Print an object to an ostream. More...
 
virtual void PrintHeader (ostream &os, vtkIndent indent)
 
virtual void PrintTrailer (ostream &os, vtkIndent indent)
 
virtual void Register (vtkObjectBase *o)
 Increase the reference count (mark as used by another object). More...
 
virtual void UnRegister (vtkObjectBase *o)
 Decrease the reference count (release by another object). More...
 
int GetReferenceCount ()
 Return the current reference count of this object. More...
 
void SetReferenceCount (int)
 Sets the reference count. More...
 
void PrintRevisions (ostream &)
 Legacy. More...
 

Static Public Member Functions

static vtkTypeBool IsTypeOf (const char *type)
 
static vtkFiniteDifferenceGradientEstimatorSafeDownCast (vtkObjectBase *o)
 
static vtkFiniteDifferenceGradientEstimatorNew ()
 Construct a vtkFiniteDifferenceGradientEstimator with a SampleSpacingInVoxels of 1. More...
 
- Static Public Member Functions inherited from vtkEncodedGradientEstimator
static vtkTypeBool IsTypeOf (const char *type)
 
static vtkEncodedGradientEstimatorSafeDownCast (vtkObjectBase *o)
 
- Static Public Member Functions inherited from vtkObject
static vtkObjectNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 
static void BreakOnError ()
 This method is called when vtkErrorMacro executes. More...
 
static void SetGlobalWarningDisplay (int val)
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static void GlobalWarningDisplayOn ()
 
static void GlobalWarningDisplayOff ()
 
static int GetGlobalWarningDisplay ()
 
- Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool IsTypeOf (const char *name)
 Return 1 if this class type is the same type of (or a subclass of) the named class. More...
 
static vtkObjectBaseNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 

Public Attributes

int SampleSpacingInVoxels
 
- Public Attributes inherited from vtkEncodedGradientEstimator
vtkImageDataInputData
 
unsigned short * EncodedNormals
 
int EncodedNormalsSize [3]
 
unsigned char * GradientMagnitudes
 
vtkTimeStamp BuildTime
 

Protected Member Functions

virtual vtkObjectBaseNewInstanceInternal () const
 
 vtkFiniteDifferenceGradientEstimator ()
 
 ~vtkFiniteDifferenceGradientEstimator () override
 
void UpdateNormals (void) override
 Recompute the encoded normals and gradient magnitudes. More...
 
- Protected Member Functions inherited from vtkEncodedGradientEstimator
 vtkEncodedGradientEstimator ()
 
 ~vtkEncodedGradientEstimator () override
 
void ReportReferences (vtkGarbageCollector *) override
 
void ComputeCircleLimits (int size)
 
- Protected Member Functions inherited from vtkObject
 vtkObject ()
 
 ~vtkObject () override
 
void RegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=nullptr)
 These methods allow a command to exclusively grab all events. More...
 
void InternalReleaseFocus ()
 
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
 
virtual ~vtkObjectBase ()
 
virtual void CollectRevisions (ostream &)
 
 vtkObjectBase (const vtkObjectBase &)
 
void operator= (const vtkObjectBase &)
 

Additional Inherited Members

- Protected Attributes inherited from vtkEncodedGradientEstimator
int NumberOfThreads
 
vtkMultiThreaderThreader
 
vtkDirectionEncoderDirectionEncoder
 
float GradientMagnitudeScale
 
float GradientMagnitudeBias
 
float LastUpdateTimeInSeconds
 
float LastUpdateTimeInCPUSeconds
 
float ZeroNormalThreshold
 
vtkTypeBool CylinderClip
 
int * CircleLimits
 
int CircleLimitsSize
 
int UseCylinderClip
 
vtkTypeBool BoundsClip
 
int Bounds [6]
 
int InputSize [3]
 
float InputAspect [3]
 
vtkTypeBool ComputeGradientMagnitudes
 
vtkTypeBool ZeroPad
 
- Protected Attributes inherited from vtkObject
bool Debug
 
vtkTimeStamp MTime
 
vtkSubjectHelper * SubjectHelper
 
- Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t > ReferenceCount
 
vtkWeakPointerBase ** WeakPointers
 

Detailed Description

Use finite differences to estimate gradient.

vtkFiniteDifferenceGradientEstimator is a concrete subclass of vtkEncodedGradientEstimator that uses a central differences technique to estimate the gradient. The gradient at some sample location (x,y,z) would be estimated by:

 nx = (f(x-dx,y,z) - f(x+dx,y,z)) / 2*dx;
 ny = (f(x,y-dy,z) - f(x,y+dy,z)) / 2*dy;
 nz = (f(x,y,z-dz) - f(x,y,z+dz)) / 2*dz;

This value is normalized to determine a unit direction vector and a magnitude. The normal is computed in voxel space, and dx = dy = dz = SampleSpacingInVoxels. A scaling factor is applied to convert this normal from voxel space to world coordinates.

See also
vtkEncodedGradientEstimator

Definition at line 45 of file vtkFiniteDifferenceGradientEstimator.h.

Member Typedef Documentation

◆ Superclass

Definition at line 49 of file vtkFiniteDifferenceGradientEstimator.h.

Constructor & Destructor Documentation

◆ vtkFiniteDifferenceGradientEstimator()

vtkFiniteDifferenceGradientEstimator::vtkFiniteDifferenceGradientEstimator ( )
protected

◆ ~vtkFiniteDifferenceGradientEstimator()

vtkFiniteDifferenceGradientEstimator::~vtkFiniteDifferenceGradientEstimator ( )
overrideprotected

Member Function Documentation

◆ IsTypeOf()

static vtkTypeBool vtkFiniteDifferenceGradientEstimator::IsTypeOf ( const char *  type)
static

◆ IsA()

virtual vtkTypeBool vtkFiniteDifferenceGradientEstimator::IsA ( const char *  name)
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 vtkEncodedGradientEstimator.

◆ SafeDownCast()

static vtkFiniteDifferenceGradientEstimator* vtkFiniteDifferenceGradientEstimator::SafeDownCast ( vtkObjectBase o)
static

◆ NewInstanceInternal()

virtual vtkObjectBase* vtkFiniteDifferenceGradientEstimator::NewInstanceInternal ( ) const
protectedvirtual

Reimplemented from vtkEncodedGradientEstimator.

◆ NewInstance()

vtkFiniteDifferenceGradientEstimator* vtkFiniteDifferenceGradientEstimator::NewInstance ( ) const

◆ PrintSelf()

void vtkFiniteDifferenceGradientEstimator::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
overridevirtual

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 vtkEncodedGradientEstimator.

◆ New()

static vtkFiniteDifferenceGradientEstimator* vtkFiniteDifferenceGradientEstimator::New ( )
static

Construct a vtkFiniteDifferenceGradientEstimator with a SampleSpacingInVoxels of 1.

◆ SetSampleSpacingInVoxels()

virtual void vtkFiniteDifferenceGradientEstimator::SetSampleSpacingInVoxels ( int  )
virtual

Set/Get the spacing between samples for the finite differences method used to compute the normal.

This spacing is in voxel units.

◆ GetSampleSpacingInVoxels()

virtual int vtkFiniteDifferenceGradientEstimator::GetSampleSpacingInVoxels ( )
virtual

◆ UpdateNormals()

void vtkFiniteDifferenceGradientEstimator::UpdateNormals ( void  )
overrideprotectedvirtual

Recompute the encoded normals and gradient magnitudes.

Implements vtkEncodedGradientEstimator.

Member Data Documentation

◆ SampleSpacingInVoxels

int vtkFiniteDifferenceGradientEstimator::SampleSpacingInVoxels

Definition at line 64 of file vtkFiniteDifferenceGradientEstimator.h.


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