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/*=========================================================================
*
* Copyright NumFOCUS
*
* 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
*
* https://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 itkSaltAndPepperNoiseImageFilter_hxx
#define itkSaltAndPepperNoiseImageFilter_hxx
#include "itkMersenneTwisterRandomVariateGenerator.h"
#include "itkImageScanlineIterator.h"
#include "itkTotalProgressReporter.h"
namespace itk
{
template <class TInputImage, class TOutputImage>
SaltAndPepperNoiseImageFilter<TInputImage, TOutputImage>::SaltAndPepperNoiseImageFilter()
: m_SaltValue(NumericTraits<OutputImagePixelType>::max())
, m_PepperValue(NumericTraits<OutputImagePixelType>::NonpositiveMin())
{
this->DynamicMultiThreadingOff();
this->ThreaderUpdateProgressOff();
}
template <class TInputImage, class TOutputImage>
void
SaltAndPepperNoiseImageFilter<TInputImage, TOutputImage>::ThreadedGenerateData(
const OutputImageRegionType & outputRegionForThread,
ThreadIdType)
{
const InputImageType * inputPtr = this->GetInput();
OutputImageType * outputPtr = this->GetOutput(0);
// Create a random generator per thread
IndexValueType indSeed = 0;
for (unsigned int d = 0; d < TOutputImage::ImageDimension; ++d)
{
indSeed += outputRegionForThread.GetIndex(d);
}
typename Statistics::MersenneTwisterRandomVariateGenerator::Pointer rand =
Statistics::MersenneTwisterRandomVariateGenerator::New();
const uint32_t seed = Self::Hash(this->GetSeed(), uint32_t(indSeed));
rand->Initialize(seed);
// Define the portion of the input to walk for this thread, using
// the CallCopyOutputRegionToInputRegion method allows for the input
// and output images to be different dimensions
InputImageRegionType inputRegionForThread;
this->CallCopyOutputRegionToInputRegion(inputRegionForThread, outputRegionForThread);
// Define the iterators
ImageScanlineConstIterator inputIt(inputPtr, inputRegionForThread);
ImageScanlineIterator outputIt(outputPtr, outputRegionForThread);
TotalProgressReporter progress(this, outputPtr->GetRequestedRegion().GetNumberOfPixels());
while (!inputIt.IsAtEnd())
{
while (!inputIt.IsAtEndOfLine())
{
if (rand->GetVariate() < m_Probability)
{
if (rand->GetVariate() < 0.5)
{
// Salt
outputIt.Set(m_SaltValue);
}
else
{
// Pepper
outputIt.Set(m_PepperValue);
}
}
else
{
// Keep the data unchanged
outputIt.Set((OutputImagePixelType)inputIt.Get());
}
++inputIt;
++outputIt;
}
inputIt.NextLine();
outputIt.NextLine();
progress.Completed(outputRegionForThread.GetSize()[0]);
}
}
template <class TInputImage, class TOutputImage>
void
SaltAndPepperNoiseImageFilter<TInputImage, TOutputImage>::PrintSelf(std::ostream & os, Indent indent) const
{
Superclass::PrintSelf(os, indent);
os << indent << "Probability: " << static_cast<typename NumericTraits<double>::PrintType>(m_Probability) << std::endl;
}
} // end namespace itk
#endif
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