com.openinventor.imageviz.engines.geometryandmatching.registration

Class SoElasticRegistrationProcessing2d

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.geometryandmatching.registration.SoElasticRegistrationProcessing2d

All Implemented Interfaces:

SafeDisposable

public class SoElasticRegistrationProcessing2d
extends SoImageVizEngine

(Preview Feature) SoElasticRegistrationProcessing2d engine

Preview Feature means this class is fully supported and can be used in Open Inventor applications. Being tagged as a Preview Feature just means that the implementation is still subject to API changes and adjustments based on feedback from early adopters. Please be also aware that source compatibility might be broken regardless of the Open Inventor compatibility changes policy due to our commitment to bring needed changes to be sure the specifications of this Preview Feature match the expectations of our customers.

The SoElasticRegistrationProcessing2d engine computes the optimal elastic transformation to register a moving image on a fixed image.

Registration is a mapping technique between two images in order to compare it. The different registration algorithms depend on the type of transformation that will be applied on the moving image.

SoElasticRegistrationProcessing2d class computes the optimal elastic transformation to register a moving image on a fixed image.

The main output of the algorithm is a displacement image representing the computed transformation. Each pixel of this image contains two values: a displacement to apply in x direction and an other to apply in y direction on the corresponding pixel of the moving image to be registered on the fixed image.

The SoElasticRegistrationProcessing2d implementation relies on the non-rigid registration demon algorithm, it is detailed in the publication:

Jean-Philippe Thirion. Image matching as a diffusion process: an analogy with Maxwell’s demons. Medical Image Analysis, Elsevier, 1998, 2 (3), pp.243–260

SoElasticRegistrationProcessing2d has two levels of regularization: fluid and elastic. The fluid regularization corresponds to the forces field regularization and the elastic one corresponds to the displacement field regularization.

The forces field is an elementary displacement which is iteratively added to the current displacement field during the registration procedure. This forces field tends to decrease the similarity measure between the 2 images.

The coarsest and the finest resolution levels of the multi-resolution can be user-defined. The registration is evaluated at the coarsest level first and then iteratively at each level until the finest one. The higher finest level, the faster the computation is. The lower finest level, the more accurate the registration is.

The multi-resolution approach prevents the optimization procedure from falling into a local extrema and also speeds up the calculation.

SoElasticRegistrationProcessing2d also proposes a multi-resolution approach.

(a) Original image. (b) Artificially distorted image. (c) Registered image.

File format/default:

ElasticRegistrationProcessing2d {

metricType	EUCLIDEAN
inFixedImage	NULL
inMovingImage	NULL
tolerance	0.025
pyramidLevels	2 0
elasticStandardDeviation	10.0f 10.0f
fluidStandardDeviation	10.0f 10.0f

}

Library references: ElasticRegistration2d

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SoElasticRegistrationProcessing2d.MetricTypes This enumeration handles all type of supported metric.

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
SoSFVec2f	elasticStandardDeviation The standard deviation in pixel of the gaussian kernel used to smooth the displacement field at each iteration.
SoSFVec2f	fluidStandardDeviation The standard deviation in pixel of the gaussian kernel used to smooth the forces field at each iteration.
SoSFImageDataAdapter	inFixedImage The reference image on which the moving image has to be registered.
SoSFImageDataAdapter	inMovingImage The input model image to be registered.
SoSFEnum<SoElasticRegistrationProcessing2d.MetricTypes>	metricType Type of metric used to measure the similarity/dissimilarity between the fixed and the transformed image.
SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter>	outDisplacementField The displacement field that maps a pixel of the moving image onto the corresponding pixel in the fixed image.
SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter>	outImage The inMovingImage transformed by the output displacement field.
SoSFVec2i32	pyramidLevels A 2-dimensional vector: first coordinate is the coarsest resolution, second coordinate is the finest resolution.
SoSFDouble	tolerance Maximum relative variation of the metric to stop the process.

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

onBegin, onEnd, onProgress

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Constructor Summary

Constructors

Constructor and Description
SoElasticRegistrationProcessing2d() 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, getName, isDisposable, isSynchronizable, setName, setSynchronizable, touch

Methods inherited from class com.openinventor.inventor.Inventor

getNativeResourceHandle

Methods inherited from class java.lang.Object

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

Field Detail

metricType

public final SoSFEnum<SoElasticRegistrationProcessing2d.MetricTypes> metricType

Type of metric used to measure the similarity/dissimilarity between the fixed and the transformed image. Only Euclidean metric is currently available. . Default is EUCLIDEAN

inFixedImage

public final SoSFImageDataAdapter inFixedImage

The reference image on which the moving image has to be registered. Default value is NULL. Supported types include: grayscale image.

inMovingImage

public final SoSFImageDataAdapter inMovingImage

The input model image to be registered. Default value is NULL. Supported types include: grayscale image.

tolerance

public final SoSFDouble tolerance

Maximum relative variation of the metric to stop the process. This variation is recomputed at each iteration. Default value is 0.025.

pyramidLevels

public final SoSFVec2i32 pyramidLevels

A 2-dimensional vector: first coordinate is the coarsest resolution, second coordinate is the finest resolution. 0 corresponds to the full resolution and N corresponds to a resolution of Default value is SbVec2i32(2,0).

elasticStandardDeviation

public final SoSFVec2f elasticStandardDeviation

The standard deviation in pixel of the gaussian kernel used to smooth the displacement field at each iteration. Default value is SbVec2f(10.0f,10.0f).

fluidStandardDeviation

public final SoSFVec2f fluidStandardDeviation

The standard deviation in pixel of the gaussian kernel used to smooth the forces field at each iteration. This parameter value is critical to reach large displacements. Default value is SbVec2f(10.0f,10.0f).

outImage

public final SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter> outImage

The inMovingImage transformed by the output displacement field. The image is in gray level. The output image has the same type than the input image which is registered. Default value is NULL. Supported types include: grayscale image.

outDisplacementField

public final SoImageVizEngineOutput<SoSFImageDataAdapter,SoImageDataAdapter> outDisplacementField

The displacement field that maps a pixel of the moving image onto the corresponding pixel in the fixed image. Each pixel of the displacement field image contains 2 values: a displacement in x direction and one in y direction. outDisplacementField is a 2D displacement field (2 spectral components) with floating point precision (32 bits). Default value is NULL. Supported types include: grayscale color image.

Constructor Detail

SoElasticRegistrationProcessing2d

public SoElasticRegistrationProcessing2d()

Constructor.