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/*=========================================================================
*
* Copyright UMC Utrecht and contributors
*
* 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 itkAdvancedLinearInterpolateImageFunction_hxx
#define itkAdvancedLinearInterpolateImageFunction_hxx
#include "itkAdvancedLinearInterpolateImageFunction.h"
#include <vnl/vnl_math.h>
namespace itk
{
/**
* ***************** EvaluateDerivativeAtContinuousIndex ***********************
*/
// template< class TInputImage, class TCoordRep >
// typename AdvancedLinearInterpolateImageFunction< TInputImage, TCoordRep >
//::CovariantVectorType
// AdvancedLinearInterpolateImageFunction< TInputImage, TCoordRep >
//::EvaluateDerivativeAtContinuousIndex(
// const ContinuousIndexType & x ) const
//{
// /**
// * Compute base index = closest index below point
// * Compute distance from point to base index
// */
// IndexType baseIndex;
// //double distance[ ImageDimension ];
// for ( dim = 0; dim < ImageDimension; dim++ )
// {
// baseIndex[ dim ] = Math::Floor< IndexValueType >( index[dim] );
// //distance[ dim ] = index[ dim ] - static_cast< double >( baseIndex[dim] );
// }
//
// IndexType neighIndex = baseIndex;
// IndexType upIndex = baseIndex;
//
// CovariantVectorType derivative;
// for ( unsigned int dim = 0; dim < ImageDimension; ++dim )
// {
// ++upIndex[ dim ];
// derivative[ dim ] =
// this->GetInputImage()->GetPixel( upIndex )
// - this->GetInputImage()->GetPixel( baseIndex );
// }
//
//} // end EvaluateDerivativeAtContinuousIndex()
/**
* ***************** EvaluateValueAndDerivativeOptimized ***********************
*/
template <class TInputImage, class TCoordRep>
void
AdvancedLinearInterpolateImageFunction<TInputImage, TCoordRep>::EvaluateValueAndDerivativeOptimized(
const Dispatch<2> &,
const ContinuousIndexType & x,
OutputType & value,
CovariantVectorType & deriv) const
{
// Get some handles
const InputImageType * inputImage = this->GetInputImage();
const InputImageSpacingType & spacing = inputImage->GetSpacing();
/** Create a possibly mirrored version of x. */
ContinuousIndexType xm = x;
double deriv_sign[ImageDimension];
for (unsigned int dim = 0; dim < ImageDimension; ++dim)
{
deriv_sign[dim] = 1.0 / spacing[dim];
if (x[dim] < this->m_StartIndex[dim])
{
xm[dim] = 2.0 * this->m_StartIndex[dim] - x[dim];
deriv_sign[dim] *= -1.0;
}
if (x[dim] > this->m_EndIndex[dim])
{
xm[dim] = 2.0 * this->m_EndIndex[dim] - x[dim];
deriv_sign[dim] *= -1.0;
}
/** Separately deal with cases on the image edge. */
if (Math::FloatAlmostEqual(xm[dim], static_cast<ContinuousIndexValueType>(this->m_EndIndex[dim])))
{
xm[dim] -= 0.000001;
}
}
// if this is mirrored again outside the image domain, then too bad.
/**
* Compute base index = closest index below point
* Compute distance from point to base index
*/
IndexType baseIndex;
double dist[ImageDimension];
double dinv[ImageDimension];
for (unsigned int dim = 0; dim < ImageDimension; ++dim)
{
baseIndex[dim] = Math::Floor<IndexValueType>(xm[dim]);
dist[dim] = xm[dim] - static_cast<double>(baseIndex[dim]);
dinv[dim] = 1.0 - dist[dim];
}
/** Get the 4 corner values. */
const RealType val00 = inputImage->GetPixel(baseIndex);
++baseIndex[0];
const RealType val10 = inputImage->GetPixel(baseIndex);
--baseIndex[0];
++baseIndex[1];
const RealType val01 = inputImage->GetPixel(baseIndex);
++baseIndex[0];
const RealType val11 = inputImage->GetPixel(baseIndex);
/** Interpolate to get the value. */
value = static_cast<OutputType>(val00 * dinv[0] * dinv[1] + val10 * dist[0] * dinv[1] + val01 * dinv[0] * dist[1] +
val11 * dist[0] * dist[1]);
/** Interpolate to get the derivative. */
deriv[0] = deriv_sign[0] * (dinv[1] * (val10 - val00) + dist[1] * (val11 - val01));
deriv[1] = deriv_sign[1] * (dinv[0] * (val01 - val00) + dist[0] * (val11 - val10));
/** Take direction cosines into account. */
deriv = inputImage->TransformLocalVectorToPhysicalVector(deriv);
} // end EvaluateValueAndDerivativeOptimized()
/**
* ***************** EvaluateValueAndDerivativeOptimized ***********************
*/
template <class TInputImage, class TCoordRep>
void
AdvancedLinearInterpolateImageFunction<TInputImage, TCoordRep>::EvaluateValueAndDerivativeOptimized(
const Dispatch<3> &,
const ContinuousIndexType & x,
OutputType & value,
CovariantVectorType & deriv) const
{
// Get some handles
const InputImageType * inputImage = this->GetInputImage();
const InputImageSpacingType & spacing = inputImage->GetSpacing();
/** Create a possibly mirrored version of x. */
ContinuousIndexType xm = x;
double deriv_sign[ImageDimension];
for (unsigned int dim = 0; dim < ImageDimension; ++dim)
{
deriv_sign[dim] = 1.0 / spacing[dim];
if (x[dim] < this->m_StartIndex[dim])
{
xm[dim] = 2.0 * this->m_StartIndex[dim] - x[dim];
deriv_sign[dim] *= -1.0;
}
if (x[dim] > this->m_EndIndex[dim])
{
xm[dim] = 2.0 * this->m_EndIndex[dim] - x[dim];
deriv_sign[dim] *= -1.0;
}
/** Separately deal with cases on the image edge. */
if (Math::FloatAlmostEqual(xm[dim], static_cast<ContinuousIndexValueType>(this->m_EndIndex[dim])))
{
xm[dim] -= 0.000001;
}
}
// if this is mirrored again outside the image domain, then too bad.
/**
* Compute base index = closest index below point
* Compute distance from point to base index
*/
IndexType baseIndex;
double dist[ImageDimension];
double dinv[ImageDimension];
for (unsigned int dim = 0; dim < ImageDimension; ++dim)
{
baseIndex[dim] = Math::Floor<IndexValueType>(xm[dim]);
dist[dim] = xm[dim] - static_cast<double>(baseIndex[dim]);
dinv[dim] = 1.0 - dist[dim];
}
/** Get the 8 corner values. */
const RealType val000 = inputImage->GetPixel(baseIndex);
++baseIndex[0];
const RealType val100 = inputImage->GetPixel(baseIndex);
++baseIndex[1];
const RealType val110 = inputImage->GetPixel(baseIndex);
++baseIndex[2];
const RealType val111 = inputImage->GetPixel(baseIndex);
--baseIndex[1];
const RealType val101 = inputImage->GetPixel(baseIndex);
--baseIndex[0];
const RealType val001 = inputImage->GetPixel(baseIndex);
++baseIndex[1];
const RealType val011 = inputImage->GetPixel(baseIndex);
--baseIndex[2];
const RealType val010 = inputImage->GetPixel(baseIndex);
/** Interpolate to get the value. */
value = static_cast<OutputType>(val000 * dinv[0] * dinv[1] * dinv[2] + val100 * dist[0] * dinv[1] * dinv[2] +
val010 * dinv[0] * dist[1] * dinv[2] + val001 * dinv[0] * dinv[1] * dist[2] +
val110 * dist[0] * dist[1] * dinv[2] + val011 * dinv[0] * dist[1] * dist[2] +
val101 * dist[0] * dinv[1] * dist[2] + val111 * dist[0] * dist[1] * dist[2]);
/** Interpolate to get the derivative. */
deriv[0] = deriv_sign[0] * (dinv[1] * dinv[2] * (val100 - val000) + dist[1] * dinv[2] * (val110 - val010) +
dinv[1] * dist[2] * (val101 - val001) + dist[1] * dist[2] * (val111 - val011));
deriv[1] = deriv_sign[1] * (dinv[0] * dinv[2] * (val010 - val000) + dist[0] * dinv[2] * (val110 - val100) +
dinv[0] * dist[2] * (val011 - val001) + dist[0] * dist[2] * (val111 - val101));
deriv[2] = deriv_sign[2] * (dinv[0] * dinv[1] * (val001 - val000) + dist[0] * dinv[1] * (val101 - val100) +
dinv[0] * dist[1] * (val011 - val010) + dist[0] * dist[1] * (val111 - val110));
/** Take direction cosines into account. */
deriv = inputImage->TransformLocalVectorToPhysicalVector(deriv);
} // end EvaluateValueAndDerivativeOptimized()
} // end namespace itk
#endif
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