| SoNonLocalMeansFilterProcessing Class |
OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising.SoNonLocalMeansFilterProcessing engine.
Inheritance HierarchyOIV.InventorSoNetBase
OIV.InventorSoDisposable
OIV.Inventor.MiscSoBase
OIV.Inventor.FieldsSoFieldContainer
OIV.Inventor.EnginesSoEngine
OIV.ImageViz.EnginesSoImageVizEngine
OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoisingSoNonLocalMeansFilterProcessing
Namespace: OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising
Assembly: OIV.ImageViz (in OIV.ImageViz.dll) Version: 2023.1.3.0 (2023.1.3)
SyntaxThe SoNonLocalMeansFilterProcessing type exposes the following members.
Constructors| Name | Description | |
|---|---|---|
 | SoNonLocalMeansFilterProcessing | 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 | |
|---|---|---|
 | computeMode | Select the compute Mode (2D or 3D or AUTO) . |
| inImage | Input image. |
| IsDisposable | ISafeDisposable interface implementation.
(Inherited from SoDisposable.) |
| kernelShape | The search window shape to apply. |
| kernelSize | The search window size to apply. |
| outImage | The output image. |
| patchSize | The patch box size to apply. |
| similarity | The similarity is used to compute weight assigned to each voxel in the search window (see expression of |
| 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. |
RemarksThe OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising.SoNonLocalMeansFilterProcessing engine implements the non-local means algorithm for image denoising.
The algorithm computes a weighted mean of a large set of voxels (search windows) around the voxel to be denoised (target voxel). The voxel weight in the search window is a function of the similarity between this voxel and the target voxel. A voxel very similar to the target voxel will be assigned to a weight close to 1.0. A voxel very different from the target voxel will be assigned to a weight close to 0 and will have a small impact on the final denoised value.
The similarity between a voxel and the target voxel is based on the squared intensity differences between 2 patches of size OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising.SoNonLocalMeansFilterProcessing.patchSize centered on the current voxel and the target voxel.
Images are often corrupted by noise because of acquisition process. For an image 
defined on 
which is the image domain, the noise added by acquisition is assimilated to an additive white gaussian noise: 
where 
The denoised image 
is an estimation of 
as following: 
with 
where:
is the similarity criterion (sum of squared differences)
is the similarity
is the indicator function of the search regionand
is the indicator function of the patch region.
The algorithm looks for matches within the search window area around each voxel.
The naive implementation of previous equation has a complexity of 
that can be reduced to 
where N*M*Q is the dimension of the input image, P is the OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising.SoNonLocalMeansFilterProcessing.patchSize and S is the OIV.ImageViz.Engines.ImageFiltering.SmoothingAndDenoising.SoNonLocalMeansFilterProcessing.kernelSize.
FILE FORMAT/DEFAULT
NonLocalMeansFilterProcessing {
| computeMode | MODE_AUTO |
| inImage | NULL |
| kernelShape | BALL |
| kernelSize | 6 |
| patchSize | 3 |
| similarity | 0.6f |
Library references: non_local_mean non_local_mean3d
See Also