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#include "LookupTableIntensityMappingFilter.h"
#include "RLEImageRegionIterator.h"
#include <itkRGBAPixel.h>
#include "LookupTableTraits.h"
template<class TInputImage, class TOutputImage>
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::LookupTableIntensityMappingFilter()
{
// The image and the LUT are inputs
this->SetNumberOfIndexedInputs(4);
}
template<class TInputImage, class TOutputImage>
void
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::SetLookupTable(LookupTableType *lut)
{
m_LookupTable = lut;
this->SetNthInput(1, lut);
}
template<class TInputImage, class TOutputImage>
void
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::SetImageMinInput(InputPixelObject *input)
{
m_InputMin = input;
this->SetNthInput(2, input);
}
template<class TInputImage, class TOutputImage>
void
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::SetImageMaxInput(InputPixelObject *input)
{
m_InputMax = input;
this->SetNthInput(3, input);
}
template<class TInputImage, class TOutputImage>
void
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::ThreadedGenerateData(const OutputImageRegionType ®ion,
itk::ThreadIdType threadId)
{
// Get the input, output and the LUT
const InputImageType *input = this->GetInput();
OutputImageType *output = this->GetOutput(0);
// Get the pointer to the zero value in the LUT
OutputPixelType *lutp =
m_LookupTable->GetBufferPointer()
- m_LookupTable->GetLargestPossibleRegion().GetIndex()[0];
// Range of the input image
InputPixelType input_min = m_InputMin->Get();
InputPixelType input_max = m_InputMax->Get();
// Compute the shift and scale factors that map the input values into
// the LUT values. These are ignored for integral pixel types, but used
// for floating point types
float lutScale;
InputPixelType lutShift;
LookupTableTraits<InputPixelType>::ComputeLinearMappingToLUT(
input_min, input_max, lutScale, lutShift);
// Define the iterators
itk::ImageRegionConstIterator<TInputImage> inputIt(input, region);
itk::ImageRegionIterator<TOutputImage> outputIt(output, region);
// Perform the intensity mapping using the LUT (no bounds checking!)
while( !inputIt.IsAtEnd() )
{
// Get the input intensity
InputPixelType xin = inputIt.Get();
OutputPixelType xout;
// TODO: we need to handle out of bounds voxels in non-orthogonal slicing
// better than this, i.e., via a special value reserved for such voxels.
// Right now, defaulting to zero is a DISASTER!
if(xin == 0 && (input_min > 0 || input_max < 0))
{
// Special case: intensity is actually outside of the min/max range
xout.Fill(0);
}
else
{
// Find the corresponding LUT offset
int lut_offset = LookupTableTraits<InputPixelType>::ComputeLUTOffset(
lutScale, lutShift, xin);
xout = *(lutp + lut_offset);
}
outputIt.Set(xout);
++inputIt;
++outputIt;
}
}
template<class TInputImage, class TOutputImage>
typename LookupTableIntensityMappingFilter<TInputImage, TOutputImage>::OutputPixelType
LookupTableIntensityMappingFilter<TInputImage, TOutputImage>
::MapPixel(const InputPixelType &xin)
{
// Make sure all the inputs are up to date
m_InputMin->Update();
m_InputMax->Update();
m_LookupTable->Update();
// Get the pointer to the zero value in the LUT
OutputPixelType *lutp =
m_LookupTable->GetBufferPointer()
- m_LookupTable->GetLargestPossibleRegion().GetIndex()[0];
// Range of the input image
InputPixelType input_min = m_InputMin->Get();
InputPixelType input_max = m_InputMax->Get();
// Compute the shift and scale factors that map the input values into
// the LUT values. These are ignored for integral pixel types, but used
// for floating point types
float lutScale;
InputPixelType lutShift;
LookupTableTraits<InputPixelType>::ComputeLinearMappingToLUT(
input_min, input_max, lutScale, lutShift);
// Get the input intensity
OutputPixelType xout;
// TODO: we need to handle out of bounds voxels in non-orthogonal slicing
// better than this, i.e., via a special value reserved for such voxels.
// Right now, defaulting to zero is a DISASTER!
if(xin == 0 && (input_min > 0 || input_max < 0))
{
// Special case: intensity is actually outside of the min/max range
xout.Fill(0);
}
else
{
// Find the corresponding LUT offset
int lut_offset = LookupTableTraits<InputPixelType>::ComputeLUTOffset(
lutScale, lutShift, xin);
xout = *(lutp + lut_offset);
}
return xout;
}
// Declare specific instances that will exist
template class LookupTableIntensityMappingFilter<
itk::Image<short, 2>, itk::Image< itk::RGBAPixel<unsigned char> > >;
template class LookupTableIntensityMappingFilter<
itk::Image<float, 2>, itk::Image< itk::RGBAPixel<unsigned char> > >;
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