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

#include <vtkSobelGradientMagnitudePass.h>

Inheritance diagram for vtkSobelGradientMagnitudePass:

Collaboration diagram for vtkSobelGradientMagnitudePass:

Public Types
typedef vtkImageProcessingPass	Superclass

typedef vtkImageProcessingPass	Superclass

Public Types inherited from vtkImageProcessingPass
typedef vtkRenderPass	Superclass

typedef vtkRenderPass	Superclass

Public Types inherited from vtkRenderPass
typedef vtkObject	Superclass

typedef vtkObject	Superclass

Public Types inherited from vtkObject
typedef vtkObjectBase	Superclass

Public Member Functions
virtual int	IsA (const char *type)

vtkSobelGradientMagnitudePass *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent)

void	ReleaseGraphicsResources (vtkWindow *w)

virtual int	IsA (const char *type)

vtkSobelGradientMagnitudePass *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent)

void	ReleaseGraphicsResources (vtkWindow *w)


virtual void	Render (const vtkRenderState *s)


virtual void	Render (const vtkRenderState *s)

Public Member Functions inherited from vtkImageProcessingPass
vtkImageProcessingPass *	NewInstance () const

vtkImageProcessingPass *	NewInstance () const

virtual vtkRenderPass *	GetDelegatePass ()

virtual void	SetDelegatePass (vtkRenderPass *delegatePass)

virtual vtkRenderPass *	GetDelegatePass ()

virtual void	SetDelegatePass (vtkRenderPass *delegatePass)

Public Member Functions inherited from vtkRenderPass
vtkRenderPass *	NewInstance () const

vtkRenderPass *	NewInstance () const

virtual int	GetNumberOfRenderedProps ()

virtual int	GetNumberOfRenderedProps ()

Public Member Functions inherited from vtkObject
vtkObject *	NewInstance () const

virtual void	DebugOn ()

virtual void	DebugOff ()

bool	GetDebug ()

void	SetDebug (bool 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)

vtkCommand *	GetCommand (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)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(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 &)

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 (vtkObjectBase *o)

static vtkSobelGradientMagnitudePass *	New ()

static int	IsTypeOf (const char *type)

static vtkSobelGradientMagnitudePass *	SafeDownCast (vtkObjectBase *o)

Static Public Member Functions inherited from vtkImageProcessingPass
static int	IsTypeOf (const char *type)

static vtkImageProcessingPass *	SafeDownCast (vtkObjectBase *o)

static int	IsTypeOf (const char *type)

static vtkImageProcessingPass *	SafeDownCast (vtkObjectBase *o)

Static Public Member Functions inherited from vtkRenderPass
static int	IsTypeOf (const char *type)

static vtkRenderPass *	SafeDownCast (vtkObjectBase *o)

static int	IsTypeOf (const char *type)

static vtkRenderPass *	SafeDownCast (vtkObjectBase *o)

Static Public Member Functions inherited from vtkObject
static int	IsTypeOf (const char *type)

static vtkObject *	SafeDownCast (vtkObjectBase *o)

static vtkObject *	New ()

static void	BreakOnError ()

static void	SetGlobalWarningDisplay (int val)

static void	GlobalWarningDisplayOn ()

static void	GlobalWarningDisplayOff ()

static int	GetGlobalWarningDisplay ()

Static Public Member Functions inherited from vtkObjectBase
static int	IsTypeOf (const char *name)

static vtkObjectBase *	New ()

Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const

	vtkSobelGradientMagnitudePass ()

virtual	~vtkSobelGradientMagnitudePass ()

virtual vtkObjectBase *	NewInstanceInternal () const

	vtkSobelGradientMagnitudePass ()

virtual	~vtkSobelGradientMagnitudePass ()

Protected Member Functions inherited from vtkImageProcessingPass
	vtkImageProcessingPass ()

virtual	~vtkImageProcessingPass ()

	vtkImageProcessingPass ()

virtual	~vtkImageProcessingPass ()

void	RenderDelegate (const vtkRenderState s, int width, int height, int newWidth, int newHeight, vtkFrameBufferObject fbo, vtkTextureObject *target)

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)

	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 &)

virtual void	ReportReferences (vtkGarbageCollector *)

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Protected Attributes
vtkOpenGLHelper *	Program1

vtkOpenGLHelper *	Program2


vtkFrameBufferObject *	FrameBufferObject

vtkTextureObject *	Pass1

vtkTextureObject *	Gx1

vtkTextureObject *	Gy1

vtkShaderProgram2 *	Program1

vtkShaderProgram2 *	Program2

Protected Attributes inherited from vtkImageProcessingPass
vtkRenderPass *	DelegatePass

Protected Attributes inherited from vtkRenderPass
int	NumberOfRenderedProps

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

Protected Attributes inherited from vtkObjectBase
vtkAtomicInt32	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:

See also: vtkRenderPass

Tests:: vtkSobelGradientMagnitudePass (Tests)

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:

See also: vtkRenderPass

Definition at line 75 of file vtkSobelGradientMagnitudePass.h.

Member Typedef Documentation

typedef vtkImageProcessingPass vtkSobelGradientMagnitudePass::Superclass

Definition at line 79 of file vtkSobelGradientMagnitudePass.h.

typedef vtkImageProcessingPass vtkSobelGradientMagnitudePass::Superclass

Definition at line 76 of file vtkSobelGradientMagnitudePass.h.

Constructor & Destructor Documentation

vtkSobelGradientMagnitudePass::vtkSobelGradientMagnitudePass ( )

protected

Default constructor. DelegatePass is set to NULL.

virtual vtkSobelGradientMagnitudePass::~vtkSobelGradientMagnitudePass ( )

protectedvirtual

Destructor.

vtkSobelGradientMagnitudePass::vtkSobelGradientMagnitudePass ( )

protected

Default constructor. DelegatePass is set to NULL.

virtual vtkSobelGradientMagnitudePass::~vtkSobelGradientMagnitudePass ( )

protectedvirtual

Destructor.

Member Function Documentation

static vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::New ( )

static

static int vtkSobelGradientMagnitudePass::IsTypeOf ( const char * type )

static

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 ( vtkObjectBase * o )

static

virtual vtkObjectBase* vtkSobelGradientMagnitudePass::NewInstanceInternal ( ) const

protectedvirtual

Reimplemented from vtkImageProcessingPass.

vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::NewInstance ( ) const

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.

static vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::New ( )

static

static int vtkSobelGradientMagnitudePass::IsTypeOf ( const char * type )

static

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 ( vtkObjectBase * o )

static

virtual vtkObjectBase* vtkSobelGradientMagnitudePass::NewInstanceInternal ( ) const

protectedvirtual

Reimplemented from vtkImageProcessingPass.

vtkSobelGradientMagnitudePass* vtkSobelGradientMagnitudePass::NewInstance ( ) const

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.