com.openinventor.imageviz.engines.edgedetection.edgemarking

Class SoZeroCrossingsProcessing2d

java.lang.Object

com.openinventor.inventor.Inventor

com.openinventor.inventor.misc.SoBase

com.openinventor.inventor.fields.SoFieldContainer

com.openinventor.inventor.engines.SoEngine

com.openinventor.imageviz.engines.SoImageVizEngine

com.openinventor.imageviz.engines.edgedetection.edgemarking.SoZeroCrossingsProcessing2d

All Implemented Interfaces:

SafeDisposable

public class SoZeroCrossingsProcessing2d
extends SoImageVizEngine

SoZeroCrossingsProcessing2d engine For an introduction to edge marking, see section Introduction to Edge Marking.

Zero-crossings are points where the Laplacian switches from positive to negative values, and vice versa.

A simple zero-crossing detection is obtained by thresholding the Laplacian to retain positive intensities, then detecting the boundaries of the binary image, as in Figure 1. Such zero-crossing points are not precisely located.

ZERO-CROSSINGS is even better to mark a point if the laplacian changes its sign in its 3x3 neighbourhood, and if the laplacian magnitude is smaller than all magnitudes in that neighbourhood, as in Figure 2.

Compared to thresholding of a gradient, zero-crossings have the advantage of producing closed curves of 1 pixel thickness. This is most interesting when precise object boundary detection is the goal.

File format/default:

ZeroCrossingsProcessing2d {

inImage

NULL

}

Library references: zero_crossings

Nested Class Summary

Nested classes/interfaces inherited from class com.openinventor.imageviz.engines.SoImageVizEngine

SoImageVizEngine.ComputeModes, SoImageVizEngine.EventArg, SoImageVizEngine.Neighborhood3ds

Nested classes/interfaces inherited from class com.openinventor.inventor.Inventor

Inventor.ConstructorCommand

Field Summary

Fields

Modifier and Type	Field and Description
SoSFImageDataAdapter	inImage The input image.
SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter>	outBinarylImage The output binary image.

Fields inherited from class com.openinventor.imageviz.engines.SoImageVizEngine

CONNECTIVITY_18, CONNECTIVITY_26, CONNECTIVITY_6, MODE_2D, MODE_3D, MODE_AUTO, onBegin, onEnd, onProgress

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Constructor Summary

Constructors

Constructor and Description
SoZeroCrossingsProcessing2d() Constructor.

Method Summary

Methods inherited from class com.openinventor.imageviz.engines.SoImageVizEngine

abortEvaluate, isEvaluating, startEvaluate, waitEvaluate

Methods inherited from class com.openinventor.inventor.engines.SoEngine

copy, getByName, getOutput, getOutputName

Methods inherited from class com.openinventor.inventor.fields.SoFieldContainer

copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults

Methods inherited from class com.openinventor.inventor.misc.SoBase

dispose, getEXTERNPROTO, getName, getPROTO, isDisposable, isSynchronizable, setName, setSynchronizable, touch

Methods inherited from class com.openinventor.inventor.Inventor

getAddress, getNativeResourceHandle, startInternalThreads, stopInternalThreads

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

inImage

public final SoSFImageDataAdapter inImage

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

outBinarylImage

public final SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter> outBinarylImage

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

Constructor Detail

SoZeroCrossingsProcessing2d

public SoZeroCrossingsProcessing2d()

Constructor.