| SoGradientOperatorProcessing2d Class |
OIV.ImageViz.Engines.EdgeDetection.Gradient.SoGradientOperatorProcessing2d engine provides different algorithms to extract the edges of a 2D image.
Inheritance HierarchyOIV.InventorSoNetBase
OIV.InventorSoDisposable
OIV.Inventor.MiscSoBase
OIV.Inventor.FieldsSoFieldContainer
OIV.Inventor.EnginesSoEngine
OIV.ImageViz.EnginesSoImageVizEngine
OIV.ImageViz.Engines.EdgeDetection.GradientSoGradientOperatorProcessing2d
Namespace: OIV.ImageViz.Engines.EdgeDetection.Gradient
Assembly: OIV.ImageViz (in OIV.ImageViz.dll) Version: 10.12.3.0 (10.12.3.0)
SyntaxThe SoGradientOperatorProcessing2d type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | SoGradientOperatorProcessing2d | Constructor. |
Methods| Name | Description | |
|---|---|---|
| AbortEvaluate | Abort current processing as soon as possible. |
| Copy | Creates and returns an exact copy of the engine. |
| CopyFieldValues(SoFieldContainer) | Calls CopyFieldValues(fc, false). (Inherited from SoFieldContainer.) |
| CopyFieldValues(SoFieldContainer, Boolean) | Copies the contents of fc's fields into this object's fields. |
| Dispose |
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.) |
| EnableNotify | Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false). |
| Equals | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
| FieldsAreEqual | Returns true if this object's fields are exactly equal to fc's fields. |
| Get | Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string. |
| GetAllFields | Returns a list of fields, including the eventIn's and eventOut's. |
| GetEventIn | Returns a the eventIn with the given name. |
| GetEventOut | Returns the eventOut with the given name. |
| GetField | Returns a the field of this object whose name is fieldName. |
| GetFieldName | Returns the name of the given field in the fieldName argument. |
| GetFields | Appends references to all of this object's fields to resultList, and returns the number of fields appended. |
| GetHashCode |
Overrides GetHashCode().
(Inherited from SoNetBase.) |
| GetName | Returns the name of an instance. |
| GetOutput | Returns a reference to the engine output with the given name. |
| GetOutputName | Returns (in outputName) the name of the engine output (output). |
| GetOutputs | Returns a list of outputs in this engine. |
| GetStringName | (Inherited from SoBase.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| HasDefaultValues | Returns true if all of the object's fields have their default values. |
| IsEvaluating | Returns true if the engine evaluation is in progress. |
| IsNotifyEnabled | Notification is the process of telling interested objects that this object has changed. |
| IsSynchronizable | Gets the ScaleViz synchronizable state of this object. |
| Set | 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. |
| SetName | (Inherited from SoBase.) |
| SetSynchronizable | Sets this to be a ScaleViz synchronizable object. |
| SetToDefaults | Sets all fields in this object to their default values. |
| StartEvaluate | Evaluate engine and dependencies in another thread without blocking the current one. |
| ToString |
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.) |
| Touch | Marks an instance as modified, simulating a change to it. |
| WaitEvaluate | Wait for the end of engine evaluation. |
Properties| Name | Description | |
|---|---|---|
 | gradientMode | Select an output mode. |
| gradientOperator | Select the gradient operator. |
| inImage | The input image. |
| IsDisposable | ISafeDisposable interface implementation.
(Inherited from SoDisposable.) |
| outAmplitudeImage | The output gradient amplitude image. |
| outGradientXImage | The output X-gradient image. |
| outGradientYImage | The output Y-gradient image. |
| outOrientationImage | The output gradient orientation image. |
| standardDeviation | The standard deviation. |
| UserData |
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.) |
Events| Name | Description | |
|---|---|---|
 | OnBegin | Event raised when the processing begins. |
| OnEnd | Event raised when processing ends and the result is available. |
| OnProgress | Event raised while processing is running. |
RemarksFor an introduction, see:
section OIV.ImageViz.Engines.ImageFiltering
section OIV.ImageViz.Engines.EdgeDetection
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