SoTopHatProcessing Class Reference
[Binarization]

SoTopHatProcessing image filter More...

#include <ImageViz/Engines/ImageSegmentation/Binarization/SoTopHatProcessing.h>

Inheritance diagram for SoTopHatProcessing:

List of all members.

Public Types
enum	ElementShape {   ROUGH = 0,   SMOOTH = 1 }
enum	ObjectLightness {   BRIGHT_OBJECTS = 0,   DARK_OBJECTS = 1 }
Public Member Functions
	SoTopHatProcessing ()
Public Attributes
SoSFEnum	computeMode
SoSFEnum	elementShape
SoSFImageDataAdapter	inGrayImage
SoSFInt32	elementSize
SoSFEnum	objectLightness
SoSFVec2f	thresholdLevel
SoImageVizEngineOutput < SoSFImageDataAdapter, SoImageDataAdapter * >	outBinaryImage

---

Detailed Description

SoTopHatProcessing image filter

The SoTopHatProcessing engine performs a Top-Hat algorithm on a gray level image.

The Top-Hat segmentation extracts small elements and details from given images. It detects the dark or the bright area, corresponding to the valleys or the narrow peaks. There exist two types of Top-Hat transform:

• The Black Top-Hat: it is defined as the difference between the closing with a particular kernel and the input image. The smaller is the kernel, the smaller are the elements in the Top-Hat image. A threshold allows selecting the darker elements of the Top-Hat result, i.e., the depth of the selected valleys. See Figure 1.
• The White Top-Hat: it is defined as the difference between the input image and its opening (using a particular kernel). The threshold allows selecting the brighter elements of the Top-Hat result.

Figure 1: Black Top-Hat computation

The Top-Hat module is divided into two phases:

• The Top-Hat image computation, depending on the Top-Hat type and the closing/opening parameters; (step 1 and 2 on figure 1)
• The Thresholding, to select the valleys/narrow peaks depth. (step 3 on figure 1)

The SoTopHatProcessing engine also includes a rough and a smooth mode. Whereas the rough mode uses a standard structuring element, the smooth mode employs a more sophisticated volumic structuring element, a rhombodecahedron, which usually generates a much more precise Top-Hat.

FILE FORMAT/DEFAULT

TopHatProcessing {

computeMode	MODE_AUTO
elementShape	ROUGH
inGrayImage	NULL
elementSize	3
objectLightness	BRIGHT_OBJECTS
thresholdLevel	128.0f 255.0f

}

Library references: high_tophat tophat

---

Member Enumeration Documentation

enum SoTopHatProcessing::ElementShape

Enumerator:

ROUGH	The Top-Hat uses a cubic structuring element.
SMOOTH	The Top-Hat uses a rhombodecahedron structuring element.

enum SoTopHatProcessing::ObjectLightness

Enumerator:

BRIGHT_OBJECTS	The engine applies a white Top-Hat and detects small bright area.
DARK_OBJECTS	The engine applies a black Top-Hat and detects small dark area. SEE ALSO SoOpeningCubeProcessing, SoClosingCubeProcessing, SoThresholdingProcessing.

---

Constructor & Destructor Documentation

SoTopHatProcessing::SoTopHatProcessing

(

)

Constructor.

---

Member Data Documentation

SoSFEnum SoTopHatProcessing::computeMode

Select the compute Mode (2D or 3D or AUTO) Use enum ComputeMode.

Default is MODE_AUTO

SoSFEnum SoTopHatProcessing::elementShape

Select the type of structuring element shape.

Use enum ElementShape. Default is ROUGH

SoSFInt32 SoTopHatProcessing::elementSize

The half size of the structuring element.

A structuring element always has an odd side length (3x3, 5x5, etc) which is defined by 2 * elementSize + 1. Default value is 3.

SoSFImageDataAdapter SoTopHatProcessing::inGrayImage

Input grey level image.

Default value is NULL. Supported types include: grayscale binary label image.

SoSFEnum SoTopHatProcessing::objectLightness

Select the lightness mode for object to detect.

Use enum ObjectLightness. Default is BRIGHT_OBJECTS

SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter*> SoTopHatProcessing::outBinaryImage

The output binary image.

Default value is NULL. Supported types include: binary image.

SoSFVec2f SoTopHatProcessing::thresholdLevel

The low and high threshold levels.

Default value is SbVec2f(128.0f,255.0f).

---

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

• ImageViz/Engines/ImageSegmentation/Binarization/SoTopHatProcessing.h