VTK
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions
vtkSobelGradientMagnitudePass Class Reference

Implement a post-processing edge detection with a Sobel gradient magnitude render pass. More...

#include <vtkSobelGradientMagnitudePass.h>

Inheritance diagram for vtkSobelGradientMagnitudePass:
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Collaboration diagram for vtkSobelGradientMagnitudePass:
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List of all members.

Public Types

typedef vtkImageProcessingPass Superclass
- Public Types inherited from vtkImageProcessingPass
- Public Types inherited from vtkRenderPass
- Public Types inherited from vtkObject

Public Member Functions

virtual const char * GetClassName ()
virtual int IsA (const char *type)
void PrintSelf (ostream &os, vtkIndent indent)
void ReleaseGraphicsResources (vtkWindow *w)
virtual void Render (const vtkRenderState *s)
- Public Member Functions inherited from vtkImageProcessingPass
virtual vtkRenderPassGetDelegatePass ()
virtual void SetDelegatePass (vtkRenderPass *delegatePass)
- Public Member Functions inherited from vtkRenderPass
virtual int GetNumberOfRenderedProps ()
- Public Member Functions inherited from vtkObject
virtual void DebugOn ()
virtual void DebugOff ()
unsigned char GetDebug ()
void SetDebug (unsigned char debugFlag)
virtual void Modified ()
virtual unsigned long GetMTime ()
unsigned long AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
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 *)
int HasObserver (unsigned long event, vtkCommand *)
int HasObserver (const char *event, vtkCommand *)
void RemoveObserver (unsigned long tag)
void RemoveObservers (unsigned long event)
void RemoveObservers (const char *event)
void RemoveAllObservers ()
int HasObserver (unsigned long event)
int HasObserver (const char *event)
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
int InvokeEvent (unsigned long event, void *callData)
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
virtual void Delete ()
virtual void FastDelete ()
void Print (ostream &os)
virtual void Register (vtkObjectBase *o)
virtual void UnRegister (vtkObjectBase *o)
void SetReferenceCount (int)
void PrintRevisions (ostream &os)
virtual void PrintHeader (ostream &os, vtkIndent indent)
virtual void PrintTrailer (ostream &os, vtkIndent indent)
int GetReferenceCount ()

Static Public Member Functions

static
vtkSobelGradientMagnitudePass
New ()
static int IsTypeOf (const char *type)
static
vtkSobelGradientMagnitudePass
SafeDownCast (vtkObject *o)

Protected Member Functions

 vtkSobelGradientMagnitudePass ()
virtual ~vtkSobelGradientMagnitudePass ()
- Protected Member Functions inherited from vtkImageProcessingPass
 vtkImageProcessingPass ()
virtual ~vtkImageProcessingPass ()
void RenderDelegate (const vtkRenderState *s, int width, int height, int newWidth, int newHeight, vtkFrameBufferObject *fbo, vtkTextureObject *target)
- Protected Member Functions inherited from vtkRenderPass
 vtkRenderPass ()
virtual ~vtkRenderPass ()
void UpdateCamera (vtkRenderer *renderer)
void ClearLights (vtkRenderer *renderer)
void UpdateLightGeometry (vtkRenderer *renderer)
void UpdateLights (vtkRenderer *renderer)
void UpdateGeometry (vtkRenderer *renderer)
void SetLastRenderingUsedDepthPeeling (vtkRenderer *renderer, bool value)
- Protected Member Functions inherited from vtkObject
 vtkObject ()
virtual ~vtkObject ()
virtual void RegisterInternal (vtkObjectBase *, int check)
virtual void UnRegisterInternal (vtkObjectBase *, int check)
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=NULL)
void InternalReleaseFocus ()
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
virtual ~vtkObjectBase ()
virtual void CollectRevisions (ostream &os)
virtual void ReportReferences (vtkGarbageCollector *)
 vtkObjectBase (const vtkObjectBase &)
void operator= (const vtkObjectBase &)

Protected Attributes

vtkFrameBufferObjectFrameBufferObject
vtkTextureObjectPass1
vtkTextureObjectGx1
vtkTextureObjectGy1
vtkShaderProgram2Program1
vtkShaderProgram2Program2
- Protected Attributes inherited from vtkImageProcessingPass
vtkRenderPassDelegatePass
- Protected Attributes inherited from vtkRenderPass
int NumberOfRenderedProps
- Protected Attributes inherited from vtkObject
unsigned char Debug
vtkTimeStamp MTime
vtkSubjectHelper * SubjectHelper
- Protected Attributes inherited from vtkObjectBase
int ReferenceCount
vtkWeakPointerBase ** WeakPointers

Detailed Description

Implement a post-processing edge detection with a Sobel gradient magnitude render pass.

Detect the edges of the image renderered by its delegate. Edge-detection uses a Sobel high-pass filter (3x3 kernel).

This pass expects an initialized depth buffer and color buffer. Initialized buffers means they have been cleared with farest z-value and background color/gradient/transparent color. An opaque pass may have been performed right after the initialization.

The delegate is used once.

Its delegate is usually set to a vtkCameraPass or to a post-processing pass.

This pass requires a OpenGL context that supports texture objects (TO), framebuffer objects (FBO) and GLSL. If not, it will emit an error message and will render its delegate and return.

Implementation:
To compute the gradient magnitude, the x and y components of the gradient (Gx and Gy) have to be computed first. Each computation of Gx and Gy uses a separable filter. The first pass takes the image from the delegate as the single input texture. The first pass has two outputs, one for the first part of Gx, Gx1, result of a convolution with (-1 0 1), one for the first part of Gy, Gy1, result of a convolution with (1 2 1). The second pass has two inputs, Gx1 and Gy1. Kernel (1 2 1)^T is applied to Gx1 and kernel (-1 0 1)^T is applied to Gx2. It gives the values for Gx and Gy. Thoses values are then used to compute the magnitude of the gradient which is stored in the render target. The gradient computation happens per component (R,G,B). A is arbitrarly set to 1 (full opacity).
Implementation:
vtkSobelGradientMagnitudePassFigure.png
See also:
vtkRenderPass
Tests:
vtkSobelGradientMagnitudePass (Tests)

Definition at line 74 of file vtkSobelGradientMagnitudePass.h.


Member Typedef Documentation

Reimplemented from vtkImageProcessingPass.

Definition at line 78 of file vtkSobelGradientMagnitudePass.h.


Constructor & Destructor Documentation

vtkSobelGradientMagnitudePass::vtkSobelGradientMagnitudePass ( )
protected

Default constructor. DelegatePass is set to NULL.

virtual vtkSobelGradientMagnitudePass::~vtkSobelGradientMagnitudePass ( )
protectedvirtual

Destructor.


Member Function Documentation

static vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::New ( )
static

Create an object with Debug turned off, modified time initialized to zero, and reference counting on.

Reimplemented from vtkObject.

virtual const char* vtkSobelGradientMagnitudePass::GetClassName ( )
virtual

Reimplemented from vtkImageProcessingPass.

static int vtkSobelGradientMagnitudePass::IsTypeOf ( const char *  name)
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 vtkImageProcessingPass.

virtual int vtkSobelGradientMagnitudePass::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 vtkImageProcessingPass.

static vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::SafeDownCast ( vtkObject o)
static

Reimplemented from vtkImageProcessingPass.

void vtkSobelGradientMagnitudePass::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
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 vtkImageProcessingPass.

virtual void vtkSobelGradientMagnitudePass::Render ( const vtkRenderState s)
virtual

Perform rendering according to a render state s.

Precondition:
s_exists: s!=0

Implements vtkRenderPass.

void vtkSobelGradientMagnitudePass::ReleaseGraphicsResources ( vtkWindow w)
virtual

Release graphics resources and ask components to release their own resources.

Precondition:
w_exists: w!=0

Reimplemented from vtkImageProcessingPass.


Member Data Documentation

vtkFrameBufferObject* vtkSobelGradientMagnitudePass::FrameBufferObject
protected

Graphics resources.

Definition at line 102 of file vtkSobelGradientMagnitudePass.h.

vtkTextureObject* vtkSobelGradientMagnitudePass::Pass1
protected

Graphics resources.

Definition at line 103 of file vtkSobelGradientMagnitudePass.h.

vtkTextureObject* vtkSobelGradientMagnitudePass::Gx1
protected

Graphics resources.

Definition at line 104 of file vtkSobelGradientMagnitudePass.h.

vtkTextureObject* vtkSobelGradientMagnitudePass::Gy1
protected

Graphics resources.

Definition at line 105 of file vtkSobelGradientMagnitudePass.h.

vtkShaderProgram2* vtkSobelGradientMagnitudePass::Program1
protected

Graphics resources.

Definition at line 106 of file vtkSobelGradientMagnitudePass.h.

vtkShaderProgram2* vtkSobelGradientMagnitudePass::Program2
protected

Graphics resources.

Definition at line 107 of file vtkSobelGradientMagnitudePass.h.


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