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/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#include "itkTranslationTransform.h"
#include "itkLinearInterpolateImageFunction.h"
#include "itkNormalizedCorrelationPointSetToImageMetric.h"
#include "itkRegularStepGradientDescentOptimizer.h"
#include "itkPointSet.h"
#include "itkPointSetToImageRegistrationMethod.h"
#include "itkImageRegistrationMethodImageSource.h"
#include "itkTestingMacros.h"
#include <iostream>
/**
*
* This program tests the registration of a PointSet against an image.
*
* This test uses two 2D-Gaussians (standard deviation RegionSize/2)
* One is shifted by 5 pixels from the other.
*
*/
int itkPointSetToImageRegistrationTest( int, char* [] )
{
const unsigned int ImageDimension = 2;
typedef double PixelType;
typedef double CoordinateRepresentationType;
typedef itk::Image< PixelType, ImageDimension > MovingImageType;
typedef itk::Image< PixelType, ImageDimension > FixedImageType;
typedef itk::testhelper::ImageRegistrationMethodImageSource<
PixelType,
PixelType,
ImageDimension > ImageSourceType;
ImageSourceType::Pointer imageSource = ImageSourceType::New();
itk::Size< ImageDimension > size;
size[0] = 100;
size[1] = 100;
imageSource->GenerateImages( size );
// Create the two images
MovingImageType::ConstPointer movingImage = imageSource->GetMovingImage();
FixedImageType::ConstPointer fixedImage = imageSource->GetFixedImage();
// Create the point set and load it with data by sampling
// the fixed image.
//
typedef itk::PointSet< float, ImageDimension > FixedPointSetType;
FixedPointSetType::Pointer fixedPointSet = FixedPointSetType::New();
const unsigned int numberOfPoints = 10000;
fixedPointSet->SetPointData( FixedPointSetType::PointDataContainer::New() );
fixedPointSet->GetPoints()->Reserve( numberOfPoints );
fixedPointSet->GetPointData()->Reserve( numberOfPoints );
typedef itk::ImageRegionConstIterator< FixedImageType > ImageIteratorType;
ImageIteratorType it( fixedImage, fixedImage->GetBufferedRegion() );
const unsigned int skip =
fixedImage->GetBufferedRegion().GetNumberOfPixels() / numberOfPoints;
unsigned int counter = 0;
FixedPointSetType::PointIdentifier pointId = 0;
FixedPointSetType::PointType point;
it.GoToBegin();
while( !it.IsAtEnd() )
{
if( counter == 0 )
{
fixedImage->TransformIndexToPhysicalPoint( it.GetIndex(), point );
fixedPointSet->SetPoint( pointId, point );
fixedPointSet->SetPointData( pointId, it.Get() );
++pointId;
if( pointId == numberOfPoints )
{
break;
}
counter = skip;
}
--counter;
++it;
}
// Set up the Metric
typedef itk::NormalizedCorrelationPointSetToImageMetric< FixedPointSetType,
MovingImageType > MetricType;
typedef MetricType::TransformType TransformBaseType;
typedef TransformBaseType::ParametersType ParametersType;
MetricType::Pointer metric = MetricType::New();
// Set up the Transform
typedef itk::TranslationTransform< CoordinateRepresentationType,
ImageDimension > TransformType;
TransformType::Pointer transform = TransformType::New();
// Set up the Interpolator
typedef itk::LinearInterpolateImageFunction< MovingImageType, double >
InterpolatorType;
InterpolatorType::Pointer interpolator = InterpolatorType::New();
// Set up the Optimizer
typedef itk::RegularStepGradientDescentOptimizer OptimizerType;
OptimizerType::Pointer optimizer = OptimizerType::New();
// Set up the Registration method
typedef itk::PointSetToImageRegistrationMethod< FixedPointSetType,
MovingImageType > RegistrationType;
RegistrationType::Pointer registration = RegistrationType::New();
EXERCISE_BASIC_OBJECT_METHODS( registration, PointSetToImageRegistrationMethod,
ProcessObject );
typedef itk::CommandIterationUpdate< OptimizerType > CommandIterationType;
// Instantiate an Observer to report the progress of the Optimization
CommandIterationType::Pointer iterationCommand = CommandIterationType::New();
iterationCommand->SetOptimizer( optimizer.GetPointer() );
// Scale the translation components of the Transform in the Optimizer
OptimizerType::ScalesType scales( transform->GetNumberOfParameters() );
scales.Fill( 1.0 );
unsigned long numberOfIterations = 50;
double maximumStepLenght = 1.0; // no step will be larger than this
double minimumStepLenght = 0.01;
double gradientTolerance = 1e-6; // convergence criterion
optimizer->SetScales( scales );
optimizer->SetNumberOfIterations( numberOfIterations );
optimizer->SetMinimumStepLength( minimumStepLenght );
optimizer->SetMaximumStepLength( maximumStepLenght );
optimizer->SetGradientMagnitudeTolerance( gradientTolerance );
optimizer->MinimizeOn();
// Connect all the components required for the registration
registration->SetMetric( metric );
TEST_SET_GET_VALUE( metric, registration->GetMetric() );
registration->SetOptimizer( optimizer );
TEST_SET_GET_VALUE( optimizer, registration->GetOptimizer() );
registration->SetTransform( transform );
TEST_SET_GET_VALUE( transform, registration->GetTransform() );
registration->SetFixedPointSet( fixedPointSet );
TEST_SET_GET_VALUE( fixedPointSet, registration->GetFixedPointSet() );
registration->SetMovingImage( movingImage );
TEST_SET_GET_VALUE( movingImage, registration->GetMovingImage() );
registration->SetInterpolator( interpolator );
TEST_SET_GET_VALUE( interpolator, registration->GetInterpolator() );
// Set up transform parameters
ParametersType parameters( transform->GetNumberOfParameters() );
// Initialize the offset/vector part
for( unsigned int k = 0; k < parameters.size(); k++ )
{
parameters[k] = 0.0f;
}
transform->SetParameters( parameters );
registration->SetInitialTransformParameters( transform->GetParameters() );
TEST_SET_GET_VALUE( transform->GetParameters(),
registration->GetInitialTransformParameters() );
TRY_EXPECT_NO_EXCEPTION( registration->Update() );
// Print the last transform parameters to improve coverage
//
ParametersType finalParameters = registration->GetLastTransformParameters();
const unsigned int numberOfParameters = parameters.Size();
std::cout << "Last Transform Parameters: " << std::endl;
for( unsigned int i = 0; i < numberOfParameters; ++i )
{
std::cout << finalParameters[i] << std::endl;
}
return EXIT_SUCCESS;
}
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