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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.
*
*=========================================================================*/
#ifndef itkApproximateSignedDistanceMapImageFilter_hxx
#define itkApproximateSignedDistanceMapImageFilter_hxx
#include "itkApproximateSignedDistanceMapImageFilter.h"
#include "itkNumericTraits.h"
#include "itkImageScanlineIterator.h"
#include "itkProgressAccumulator.h"
namespace itk
{
template< typename TInputImage, typename TOutputImage >
ApproximateSignedDistanceMapImageFilter< TInputImage, TOutputImage >
::ApproximateSignedDistanceMapImageFilter():
m_IsoContourFilter( IsoContourType::New() ),
m_ChamferFilter( ChamferType::New() ),
m_InsideValue( NumericTraits< InputPixelType >::min() ),
m_OutsideValue( NumericTraits< InputPixelType >::max() )
{
}
template< typename TInputImage, typename TOutputImage >
void
ApproximateSignedDistanceMapImageFilter< TInputImage, TOutputImage >
::GenerateData()
{
ThreadIdType numberOfThreads = this->GetNumberOfThreads();
OutputImagePointer output = this->GetOutput();
typedef typename OutputImageType::RegionType OutputRegionType;
OutputRegionType oRegion = output->GetRequestedRegion();
// Calculate the largest possible distance in the output image.
// this maximum is the distance from one corner of the image to the other.
OutputSizeType outputSize = oRegion.GetSize();
OutputSizeValueType maximumDistance = 0;
for( unsigned int i = 0; i < InputImageDimension; i++ )
{
maximumDistance += outputSize[i] * outputSize[i];
}
// Cast to double and back because there's no sqrt defined for unsigned long,
// which is the general SizeValueType.
maximumDistance =
static_cast< OutputSizeValueType >( std::sqrt( static_cast< double >( maximumDistance ) ) );
// Allocate the output
this->AllocateOutputs();
// Create a process accumulator for tracking the progress of this minipipeline
ProgressAccumulator::Pointer progress = ProgressAccumulator::New();
progress->SetMiniPipelineFilter(this);
progress->RegisterInternalFilter(m_IsoContourFilter, 0.5f);
progress->RegisterInternalFilter(m_ChamferFilter, 0.5f);
// Set up the isocontour filter
m_IsoContourFilter->SetInput( this->GetInput() );
m_IsoContourFilter->SetFarValue(maximumDistance + 1);
m_IsoContourFilter->SetNumberOfThreads( numberOfThreads );
typename IsoContourType::PixelRealType levelSetValue =
(static_cast<typename IsoContourType::PixelRealType>( m_InsideValue )
+ static_cast<typename IsoContourType::PixelRealType>(m_OutsideValue) ) / 2.0;
m_IsoContourFilter->SetLevelSetValue(levelSetValue);
// Set up the chamfer filter
m_ChamferFilter->SetInput( m_IsoContourFilter->GetOutput() );
m_ChamferFilter->SetMaximumDistance(maximumDistance);
m_ChamferFilter->SetNumberOfThreads( numberOfThreads );
// Graft our output to the chamfer filter to force the proper regions
// to be generated
m_ChamferFilter->GraftOutput( output );
// Create the distance map
m_ChamferFilter->Update();
// Graft the output of the chamfer filter back onto this filter's
// output. this is needed to get the appropriate regions passed
// back.
this->GraftOutput( m_ChamferFilter->GetOutput() );
// Recall that we set the isocontour value to halfway between the inside and
// outside value. The above filters assume that regions "inside" objects are
// those with values *less* than the isocontour. This assumption is violated
// if the "inside" intensity value is greater than the "outside" value.
// (E.g. in the case that we're computing the distance from a mask where the
// background is zero and the objects are colored 255.)
// In this case, the distance will be calculated negative, so we need to
// flip the sign of the output image.
if( m_InsideValue > m_OutsideValue )
{
ImageScanlineIterator< OutputImageType > ot( output, oRegion );
while( !ot.IsAtEnd() )
{
while( !ot.IsAtEndOfLine() )
{
ot.Set(ot.Get() * -1);
++ot;
}
ot.NextLine();
}
}
}
template< typename TInputImage, typename TOutputImage >
void
ApproximateSignedDistanceMapImageFilter< TInputImage, TOutputImage >
::PrintSelf(std::ostream & os, Indent indent) const
{
Superclass::PrintSelf(os, indent);
os << indent << "Inside intensity value: " << m_InsideValue << std::endl;
os << indent << "Outside intensity value: " << m_OutsideValue << std::endl;
os << indent << "IsoContourDistanceImageFilter (used internally): "
<< m_IsoContourFilter << std::endl;
os << indent << "FastChamferDistanceImageFilter (used internally): "
<< m_ChamferFilter << std::endl;
}
} // end of namespace itk
#endif
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