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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 "itkImageToListSampleFilter.h"
#include "itkStandardDeviationPerComponentSampleFilter.h"
#include "itkImageRegionIterator.h"
#include "itkCovarianceSampleFilter.h"
int itkStandardDeviationPerComponentSampleFilterTest(int, char* [] )
{
std::cout << "StandardDeviationPerComponentSampleFilter Test \n \n";
// Now generate an image
enum { MeasurementVectorSize = 3 };
typedef float MeasurementType;
typedef itk::FixedArray< MeasurementType, MeasurementVectorSize > MeasurementVectorType;
typedef itk::Image< MeasurementVectorType, MeasurementVectorSize > ImageType;
typedef itk::Image< unsigned char, MeasurementVectorSize > MaskImageType;
ImageType::Pointer image = ImageType::New();
ImageType::RegionType region;
ImageType::SizeType size;
ImageType::IndexType index;
index.Fill(0);
size.Fill(5);
region.SetIndex(index);
region.SetSize(size);
image->SetBufferedRegion(region);
image->Allocate();
typedef itk::ImageRegionIterator< ImageType > ImageIterator;
ImageIterator iter(image, region);
unsigned int count = 0;
MeasurementVectorType temp;
temp.Fill(0);
// fill the image
while (!iter.IsAtEnd())
{
temp[0] = count;
temp[1] = 2 * count;
temp[2] = 3 * count;
iter.Set(temp);
++iter;
++count;
}
// creates an ImageToListSampleAdaptor object
typedef itk::Statistics::ImageToListSampleFilter< ImageType, MaskImageType >
ImageToListSampleFilterType;
ImageToListSampleFilterType::Pointer sampleGeneratingFilter
= ImageToListSampleFilterType::New();
sampleGeneratingFilter->SetInput( image );
try
{
sampleGeneratingFilter->Update();
}
catch( itk::ExceptionObject & excp )
{
std::cerr<< excp << std::endl;
return EXIT_FAILURE;
}
typedef ImageToListSampleFilterType::ListSampleType ListSampleType;
typedef itk::Statistics::StandardDeviationPerComponentSampleFilter< ListSampleType > StandardDeviationPerComponentSampleFilterType;
StandardDeviationPerComponentSampleFilterType::Pointer standardDeviationFilter = StandardDeviationPerComponentSampleFilterType::New();
std::cout << standardDeviationFilter->GetNameOfClass() << std::endl;
//Invoke update before adding an input. An exception should be
try
{
standardDeviationFilter->Update();
std::cerr << "Exception should have been thrown since \
Update() is invoked without setting an input " << std::endl;
return EXIT_FAILURE;
}
catch ( itk::ExceptionObject & excp )
{
std::cerr << "Exception caught: " << excp << std::endl;
}
standardDeviationFilter->ResetPipeline();
if ( standardDeviationFilter->GetInput() != ITK_NULLPTR )
{
std::cerr << "GetInput() should return ITK_NULLPTR if the input \
has not been set" << std::endl;
return EXIT_FAILURE;
}
standardDeviationFilter->SetInput( sampleGeneratingFilter->GetOutput() );
try
{
standardDeviationFilter->Update();
}
catch( itk::ExceptionObject & excp )
{
std::cerr<< excp << std::endl;
return EXIT_FAILURE;
}
standardDeviationFilter->Print( std::cout );
const double epsilon = 1e-6;
// CHECK THE RESULTS
typedef StandardDeviationPerComponentSampleFilterType::MeasurementVectorRealType MeasurementVectorRealType;
typedef StandardDeviationPerComponentSampleFilterType::MeasurementVectorRealDecoratedType MeasurementVectorRealDecoratedType;
const MeasurementVectorRealDecoratedType * standardDeviationDecorator =
standardDeviationFilter->GetStandardDeviationPerComponentOutput();
const MeasurementVectorRealDecoratedType * meanDecorator =
standardDeviationFilter->GetMeanPerComponentOutput();
MeasurementVectorRealType standardDeviation = standardDeviationDecorator->Get();
std::cout << "Standard deviation: " << standardDeviation << std::endl;
MeasurementVectorRealType mean = meanDecorator->Get();
std::cout << "Mean : " << mean << std::endl;
MeasurementVectorRealType standardDeviation2 = standardDeviationFilter->GetStandardDeviationPerComponent();
if ( ( itk::Math::abs( standardDeviation[0] - standardDeviation2[0]) > epsilon ) ||
( itk::Math::abs( standardDeviation[1] - standardDeviation2[1]) > epsilon ) ||
( itk::Math::abs( standardDeviation[2] - standardDeviation2[2]) > epsilon ) )
{
std::cerr << "Standard Deviation value retrieved using Get() and the decorator\
are not the same:: " << standardDeviation << "," << standardDeviation2 << std::endl;
return EXIT_FAILURE;
}
typedef itk::Statistics::CovarianceSampleFilter< ListSampleType > CovarianceSampleFilterType;
CovarianceSampleFilterType::Pointer covarianceFilter = CovarianceSampleFilterType::New();
covarianceFilter->SetInput( sampleGeneratingFilter->GetOutput());
try
{
covarianceFilter->Update();
}
catch( itk::ExceptionObject & excp )
{
std::cerr << "Exception caught: " << excp << std::endl;
}
CovarianceSampleFilterType::MeasurementVectorRealType meanCalculatedUsingCovarianceSampleFilter = covarianceFilter->GetMean();
if ( ( itk::Math::abs( meanCalculatedUsingCovarianceSampleFilter[0] - mean[0]) > epsilon ) ||
( itk::Math::abs( meanCalculatedUsingCovarianceSampleFilter[1] - mean[1]) > epsilon ) ||
( itk::Math::abs( meanCalculatedUsingCovarianceSampleFilter[2] - mean[2]) > epsilon ) )
{
std::cerr << "Mean calculated using the CovarianceSampleFilter is different from\
the one calculated using the StandardDeviationPerComponentSampleFilter " << std::endl;
return EXIT_FAILURE;
}
CovarianceSampleFilterType::MatrixType covarianceCalculatedUsingCovarianceSampleFilter = covarianceFilter->GetCovarianceMatrix();
for( unsigned int k = 0; k < MeasurementVectorSize; k++ )
{
const double variance = covarianceCalculatedUsingCovarianceSampleFilter(k,k);
const double standardDeviationValue = std::sqrt( variance );
if ( ( itk::Math::abs( standardDeviationValue - standardDeviation[k] ) > epsilon ) )
{
std::cerr << "Standard deviation calculated using the CovarianceSampleFilter";
std::cerr << " (as the square root of the diagonal) is different from ";
std::cerr << " the one calculated using the StandardDeviationPerComponentSampleFilter " << std::endl;
return EXIT_FAILURE;
}
}
std::cout << "Test passed." << std::endl;
return EXIT_SUCCESS;
}
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