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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 "itkInvertDisplacementFieldImageFilter.h"
#include "itkImageRegionIteratorWithIndex.h"
int itkInvertDisplacementFieldImageFilterTest( int, char * [] )
{
const unsigned int ImageDimension = 2;
typedef itk::Vector<float, ImageDimension> VectorType;
typedef itk::Image<VectorType, ImageDimension> DisplacementFieldType;
// Create a displacement field
DisplacementFieldType::PointType origin;
DisplacementFieldType::SpacingType spacing;
DisplacementFieldType::SizeType size;
DisplacementFieldType::DirectionType direction;
direction.SetIdentity();
origin.Fill( 0.0 );
spacing.Fill( 0.5 );
size.Fill( 100 );
VectorType ones( 1 );
DisplacementFieldType::Pointer field = DisplacementFieldType::New();
field->SetOrigin( origin );
field->SetSpacing( spacing );
field->SetRegions( size );
field->SetDirection( direction );
field->Allocate();
field->FillBuffer( ones );
const VectorType zeroVector( 0.0 );
//make sure boundary does not move
float weight1 = 1.0;
const DisplacementFieldType::RegionType region = field->GetLargestPossibleRegion();
const DisplacementFieldType::IndexType startIndex = region.GetIndex();
itk::ImageRegionIteratorWithIndex<DisplacementFieldType> ItF( field, field->GetLargestPossibleRegion() );
for( ItF.GoToBegin(); !ItF.IsAtEnd(); ++ItF )
{
DisplacementFieldType::IndexType index = ItF.GetIndex();
bool isOnBoundary = false;
for ( unsigned int d = 0; d < ImageDimension; d++ )
{
if( index[d] == startIndex[d] || index[d] == static_cast<int>( size[d] ) - startIndex[d] - 1 )
{
isOnBoundary = true;
break;
}
}
if( isOnBoundary )
{
ItF.Set( zeroVector );
}
else
{
ItF.Set( ItF.Get() * weight1 );
}
}
unsigned int numberOfIterations = 50;
float maxTolerance = 0.1;
float meanTolerance = 0.001;
typedef itk::InvertDisplacementFieldImageFilter<DisplacementFieldType> InverterType;
InverterType::Pointer inverter = InverterType::New();
inverter->SetInput( field );
inverter->SetMaximumNumberOfIterations( numberOfIterations );
inverter->SetMeanErrorToleranceThreshold( meanTolerance );
inverter->SetMaxErrorToleranceThreshold( maxTolerance );
inverter->SetEnforceBoundaryCondition( false );
std::cout << "number of iterations: " << inverter->GetMaximumNumberOfIterations() << std::endl;
std::cout << "mean error tolerance: " << inverter->GetMeanErrorToleranceThreshold() << std::endl;
std::cout << "max error tolerance: " << inverter->GetMaxErrorToleranceThreshold() << std::endl;
try
{
inverter->Update();
}
catch( itk::ExceptionObject & excp )
{
std::cerr << "Exception thrown " << std::endl;
std::cerr << excp << std::endl;
}
DisplacementFieldType::IndexType index;
index[0] = 30;
index[1] = 30;
VectorType v = inverter->GetOutput()->GetPixel( index );
VectorType delta = v + ones;
if( delta.GetNorm() > 0.05 )
{
std::cerr << "Failed to find proper inverse." << std::endl;
return EXIT_FAILURE;
}
if( inverter->GetMeanErrorNorm() > inverter->GetMeanErrorToleranceThreshold() &&
inverter->GetMaxErrorNorm() > inverter->GetMaxErrorToleranceThreshold() )
{
std::cerr << "Failed to converge properly." << std::endl;
return EXIT_FAILURE;
}
inverter->Print( std::cout, 3 );
return EXIT_SUCCESS;
}
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