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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 itkIsolatedWatershedImageFilter_hxx
#define itkIsolatedWatershedImageFilter_hxx
#include "itkIsolatedWatershedImageFilter.h"
#include "itkProgressReporter.h"
#include "itkIterationReporter.h"
namespace itk
{
template< typename TInputImage, typename TOutputImage >
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::IsolatedWatershedImageFilter()
{
m_Threshold = NumericTraits< InputImagePixelType >::ZeroValue();
m_Seed1.Fill(0);
m_Seed2.Fill(0);
m_ReplaceValue1 = NumericTraits< OutputImagePixelType >::OneValue();
m_ReplaceValue2 = NumericTraits< OutputImagePixelType >::ZeroValue();
m_IsolatedValue = 0.0;
m_IsolatedValueTolerance = 0.001;
m_UpperValueLimit = 1.0;
m_GradientMagnitude = GradientMagnitudeType::New();
m_Watershed = WatershedType::New();
}
template< typename TInputImage, typename TOutputImage >
void
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::GenerateInputRequestedRegion()
{
Superclass::GenerateInputRequestedRegion();
if ( this->GetInput() )
{
InputImagePointer image =
const_cast< TInputImage * >( this->GetInput() );
image->SetRequestedRegionToLargestPossibleRegion();
}
}
template< typename TInputImage, typename TOutputImage >
void
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::EnlargeOutputRequestedRegion(DataObject *output)
{
Superclass::EnlargeOutputRequestedRegion(output);
output->SetRequestedRegionToLargestPossibleRegion();
}
template< typename TInputImage, typename TOutputImage >
void
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::VerifyInputInformation()
{
Superclass::VerifyInputInformation();
const InputImageType *inputImage = this->GetInput();
const InputImageRegionType region = inputImage->GetRequestedRegion();
// Check that the seeds are valid after the input has had its output
// information updated
if ( !region.IsInside(m_Seed1) )
{
itkExceptionMacro("Seed1 is not within the input image!");
}
if ( !region.IsInside(m_Seed2) )
{
itkExceptionMacro("Seed2 is not within the input image!");
}
}
template< typename TInputImage, typename TOutputImage >
void
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::GenerateData()
{
const InputImageType *inputImage = this->GetInput();
OutputImageType *outputImage = this->GetOutput();
OutputImageRegionType region = outputImage->GetRequestedRegion();
// Set up the pipeline
m_GradientMagnitude->SetInput (inputImage);
// Set up the Watershed
m_Watershed->SetInput( m_GradientMagnitude->GetOutput() );
m_Watershed->SetThreshold( m_Threshold );
m_Watershed->SetLevel( m_UpperValueLimit );
// Allocate the output
this->AllocateOutputs();
double lower = m_Threshold;
double upper = m_UpperValueLimit;
double guess = upper;
const unsigned int maximumIterationsInBinarySearch =
static_cast< unsigned int >(
std::log( ( static_cast< float >( upper ) - static_cast< float >( lower ) )
/ static_cast< float >( m_IsolatedValueTolerance ) ) / std::log(2.0) );
const float progressWeight = 1.0f / static_cast< float >( maximumIterationsInBinarySearch + 2 );
float cumulatedProgress = 0.0f;
IterationReporter iterate(this, 0, 1);
// Do a binary search to find an upper waterlevel that separates the
// two seeds.
while ( lower + m_IsolatedValueTolerance < guess )
{
ProgressReporter progress(this, 0, region.GetNumberOfPixels(), 100, cumulatedProgress, progressWeight);
cumulatedProgress += progressWeight;
m_Watershed->SetLevel (guess);
m_Watershed->Update ();
if ( m_Watershed->GetOutput()->GetPixel(m_Seed1) == m_Watershed->GetOutput()->GetPixel(m_Seed2) )
{
upper = guess;
}
else
{
lower = guess;
}
guess = ( upper + lower ) / 2;
iterate.CompletedStep();
}
// If the watershed basins are not separated or if the upper/lower
// threshold were not valid, then use lower.
if ( m_Watershed->GetOutput()->GetBufferedRegion() != region
|| m_Watershed->GetOutput()->GetPixel(m_Seed1) ==
m_Watershed->GetOutput()->GetPixel(m_Seed2) )
{
m_Watershed->SetLevel (lower);
m_Watershed->Update ();
}
// Now produce an output image with the two seeded basins labeled
ProgressReporter progress(this, 0, region.GetNumberOfPixels(), 100, cumulatedProgress, progressWeight);
ImageRegionIterator< OutputImageType > ot =
ImageRegionIterator< OutputImageType >(outputImage, region);
ImageRegionIterator< typename WatershedType::OutputImageType > it =
ImageRegionIterator< typename WatershedType::OutputImageType >(m_Watershed->GetOutput(), region);
IdentifierType seed1Label = m_Watershed->GetOutput()->GetPixel(m_Seed1);
IdentifierType seed2Label = m_Watershed->GetOutput()->GetPixel(m_Seed2);
IdentifierType value;
it.GoToBegin();
ot.GoToBegin();
while ( !it.IsAtEnd() )
{
value = it.Get();
if ( value == seed1Label )
{
ot.Set(m_ReplaceValue1);
}
else if ( value == seed2Label )
{
ot.Set(m_ReplaceValue2);
}
else
{
ot.Set(NumericTraits< OutputImagePixelType >::ZeroValue());
}
++it;
++ot;
progress.CompletedPixel(); // potential exception thrown here
}
m_IsolatedValue = lower;
iterate.CompletedStep();
}
template< typename TInputImage, typename TOutputImage >
void
IsolatedWatershedImageFilter< TInputImage, TOutputImage >
::PrintSelf(std::ostream & os, Indent indent) const
{
this->Superclass::PrintSelf(os, indent);
os << indent << "Threshold: "
<< m_Threshold
<< std::endl;
os << indent << "UpperValueLimit: "
<< m_UpperValueLimit
<< std::endl;
os << indent << "ReplaceValue1: "
<< static_cast< typename NumericTraits< OutputImagePixelType >::PrintType >( m_ReplaceValue1 )
<< std::endl;
os << indent << "ReplaceValue2: "
<< static_cast< typename NumericTraits< OutputImagePixelType >::PrintType >( m_ReplaceValue2 )
<< std::endl;
os << indent << "Seed1: " << m_Seed1 << std::endl;
os << indent << "Seed2: " << m_Seed2 << std::endl;
os << indent << "IsolatedValue: "
<< m_IsolatedValue
<< std::endl;
os << indent << "IsolatedValueTolerance: "
<< m_IsolatedValueTolerance
<< std::endl;
}
} // end namespace itk
#endif
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