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SoGradientOperatorProcessing2d Class

OIV.ImageViz.Engines.EdgeDetection.Gradient.SoGradientOperatorProcessing2d engine provides different algorithms to extract the edges of a 2D image.

Inheritance Hierarchy

Namespace: OIV.ImageViz.Engines.EdgeDetection.Gradient
Assembly: OIV.ImageViz (in OIV.ImageViz.dll) Version: 10.12.3.0 (10.12.3.0)
Syntax
public class SoGradientOperatorProcessing2d : SoImageVizEngine

The SoGradientOperatorProcessing2d type exposes the following members.

Constructors
  NameDescription
Public methodSoGradientOperatorProcessing2d

Constructor.

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Methods
  NameDescription
Public methodAbortEvaluate

Abort current processing as soon as possible.

(Inherited from SoImageVizEngine.)
Public methodCopy

Creates and returns an exact copy of the engine.

(Inherited from SoEngine.)
Public methodCopyFieldValues(SoFieldContainer)
Calls CopyFieldValues(fc, false).
(Inherited from SoFieldContainer.)
Public methodCopyFieldValues(SoFieldContainer, Boolean)

Copies the contents of fc's fields into this object's fields.

(Inherited from SoFieldContainer.)
Public methodDispose
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.)
Public methodEnableNotify

Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false).

(Inherited from SoFieldContainer.)
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Public methodFieldsAreEqual

Returns true if this object's fields are exactly equal to fc's fields.

(Inherited from SoFieldContainer.)
Public methodGet

Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.

(Inherited from SoFieldContainer.)
Public methodGetAllFields

Returns a list of fields, including the eventIn's and eventOut's.

(Inherited from SoFieldContainer.)
Public methodGetEventIn

Returns a the eventIn with the given name.

(Inherited from SoFieldContainer.)
Public methodGetEventOut

Returns the eventOut with the given name.

(Inherited from SoFieldContainer.)
Public methodGetField

Returns a the field of this object whose name is fieldName.

(Inherited from SoFieldContainer.)
Public methodGetFieldName

Returns the name of the given field in the fieldName argument.

(Inherited from SoFieldContainer.)
Public methodGetFields

Appends references to all of this object's fields to resultList, and returns the number of fields appended.

(Inherited from SoFieldContainer.)
Public methodGetHashCode
Overrides GetHashCode().
(Inherited from SoNetBase.)
Public methodGetName

Returns the name of an instance.

(Inherited from SoBase.)
Public methodGetOutput

Returns a reference to the engine output with the given name.

(Inherited from SoEngine.)
Public methodGetOutputName

Returns (in outputName) the name of the engine output (output).

(Inherited from SoEngine.)
Public methodGetOutputs

Returns a list of outputs in this engine.

(Inherited from SoEngine.)
Public methodGetStringName (Inherited from SoBase.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodHasDefaultValues

Returns true if all of the object's fields have their default values.

(Inherited from SoFieldContainer.)
Public methodIsEvaluating

Returns true if the engine evaluation is in progress.

(Inherited from SoImageVizEngine.)
Public methodIsNotifyEnabled

Notification is the process of telling interested objects that this object has changed.

(Inherited from SoFieldContainer.)
Public methodIsSynchronizable

Gets the ScaleViz synchronizable state of this object.

(Inherited from SoBase.)
Public methodSet

Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.

(Inherited from SoFieldContainer.)
Public methodSetName (Inherited from SoBase.)
Public methodSetSynchronizable

Sets this to be a ScaleViz synchronizable object.

(Inherited from SoBase.)
Public methodSetToDefaults

Sets all fields in this object to their default values.

(Inherited from SoFieldContainer.)
Public methodStartEvaluate

Evaluate engine and dependencies in another thread without blocking the current one.

(Inherited from SoImageVizEngine.)
Public methodToString
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.)
Public methodTouch

Marks an instance as modified, simulating a change to it.

(Inherited from SoBase.)
Public methodWaitEvaluate

Wait for the end of engine evaluation.

(Inherited from SoImageVizEngine.)
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Properties
  NameDescription
Public propertygradientMode

Select an output mode.

Public propertygradientOperator

Select the gradient operator.

Public propertyinImage

The input image.

Public propertyIsDisposable
ISafeDisposable interface implementation.
(Inherited from SoDisposable.)
Public propertyoutAmplitudeImage

The output gradient amplitude image.

Public propertyoutGradientXImage

The output X-gradient image.

Public propertyoutGradientYImage

The output Y-gradient image.

Public propertyoutOrientationImage

The output gradient orientation image.

Public propertystandardDeviation

The standard deviation.

Public propertyUserData
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.)
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Events
  NameDescription
Public eventOnBegin

Event raised when the processing begins.

(Inherited from SoImageVizEngine.)
Public eventOnEnd

Event raised when processing ends and the result is available.

(Inherited from SoImageVizEngine.)
Public eventOnProgress

Event raised while processing is running.

(Inherited from SoImageVizEngine.)
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Remarks

For an introduction, see:

The OIV.ImageViz.Engines.EdgeDetection.Gradient.SoGradientOperatorProcessing2d engine provides different algorithms to extract the edges of an image.

Note: You may normalize the filtered image, i.e. divide the output gray levels by the sum of absolute values of the kernel coefficients. If not, be aware that overflow may occur.

  • Canny-Deriche: It performs a recursive gradient computation to get the gradient in X and Y directions. It is an FIR (finite impulse response) filter. To minimize the effect of noise, it smooths the image before computing the gradient. A smoothing scale parameter determines the smoothing intensity. If the value is large, noise will be reduced but edges will be less sharp and only the most significant edges will survive. It is important to select the right coefficient to lower the noise just enough without defocusing the edges. Then it gets the maximum of these images with a gradient magnitude operation. For color images it calculates the maximum of intensity or the euclidian mean.

  • Shen-Castan: It calculates the gradient of Shen and Castan. It is a recursive and exponential filter that smooths an object and then extracts its edges. It is based on the Shen operator :

The highest is, the more edges we get. For color images it calculates the maximum of intensity or the euclidian mean.

  • Canny: It performs an approximation to get the Canny-Deriche in X and Y directions using a convolution kernel 7x5 for X and 5x7 for Y. Result is nearly the same than Canny Deriche but process is much faster.

  • Gaussian: It performs a convolution with the derivatives of a Gaussian function along each image axis.

  • Sobel: It performs a convolution with the Sobel Kernel.

  • Prewitt: It performs a convolution with the Prewitt Kernel.

FILE FORMAT/DEFAULT

GradientOperatorProcessing2d {
inImage NULL
gradientOperator CANNY_DERICHE
gradientMode AMPLITUDE_MAX_OF_MAGS
standardDeviation 60.0f
}

Library references: gradient

See Also