float operator()(const ImagePatchType& a, const ImagePatchType& b) const
{
// This comparison must allow source patches to be compared to source patches (to create the tree) as well as source patches
// to be symmetrically compared to target patches.
DifferenceFunctorType differenceFunctor;
if(!a.IsInsideImage() || !b.IsInsideImage())
{
return std::numeric_limits<float>::infinity();
}
// If we are comparing a patch to itself, return inf. Otherwise, the best match would always be the same patch!
if(a.GetRegion() == b.GetRegion())
{
return std::numeric_limits<float>::infinity();
}
// If either patch is invalid, the comparison cannot be performed.
if(a.GetStatus() == ImagePatchType::INVALID || b.GetStatus() == ImagePatchType::INVALID)
{
return std::numeric_limits<float>::infinity();
}
float totalDifference = 0.0f;
// If both nodes are source nodes, compare them fully.
if(a.GetStatus() == ImagePatchType::SOURCE_NODE && b.GetStatus() == ImagePatchType::SOURCE_NODE)
{
typename std::vector<itk::Index<2> >::const_iterator iterA = a.GetIndexVector().begin();
typename std::vector<itk::Index<2> >::const_iterator iterB = b.GetIndexVector().begin();
for(;iterA != a.GetIndexVector().end(); ++iterA, ++iterB)
{
float pixelDifference = differenceFunctor(a.GetImage()->GetPixel(*iterA), b.GetImage()->GetPixel(*iterB));
totalDifference += pixelDifference;
}
totalDifference = totalDifference / static_cast<float>(a.GetRegion().GetNumberOfPixels());
}
// If one of the nodes is a target node, only compare in it's list of valid offset pixels.
else if(a.GetStatus() == ImagePatchType::TARGET_NODE || b.GetStatus() == ImagePatchType::TARGET_NODE)
{
typedef std::vector<unsigned int> OffsetVectorType;
const OffsetVectorType* validOffsets;
if(a.GetStatus() == ImagePatchType::TARGET_NODE)
{
validOffsets = a.GetValidOffsetsAddress();
}
if(b.GetStatus() == ImagePatchType::TARGET_NODE)
{
validOffsets = b.GetValidOffsetsAddress();
}
for(OffsetVectorType::const_iterator iter = validOffsets->begin(); iter < validOffsets->end(); ++iter)
{
float difference = differenceFunctor(a.GetImage()->GetPixel(a.GetIndexVector()[*iter]),
b.GetImage()->GetPixel(b.GetIndexVector()[*iter]));
totalDifference += difference;
}
totalDifference = totalDifference / static_cast<float>(validOffsets->size());
}
else
{
std::stringstream ss;
ss << "Patch statuses are not correct! Status(a) is " << a.GetStatus() << " and Status(b) is " << b.GetStatus();
throw std::runtime_error(ss.str());
}
//std::cout << "Difference: " << totalDifference << std::endl;
return totalDifference;
}
float operator()(const ImagePatchType& a, const ImagePatchType& b) const
{
assert(Weights.size() == a.GetImage()->GetNumberOfComponentsPerPixel());
// This comparison must allow source patches to be compared to source patches (to create the tree) as well as source patches
// to be symmetrically compared to target patches.
if(!a.IsInsideImage() || !b.IsInsideImage())
{
return std::numeric_limits<float>::infinity();
}
// If we are comparing a patch to itself, return inf. Otherwise, the best match would always be the same patch!
if(a.GetRegion() == b.GetRegion())
{
return std::numeric_limits<float>::infinity();
}
// If either patch is invalid, the comparison cannot be performed.
if(a.GetStatus() == ImagePatchType::INVALID || b.GetStatus() == ImagePatchType::INVALID)
{
return std::numeric_limits<float>::infinity();
}
// For now this image is required to be the same for both patches.
assert(a.GetImage() == b.GetImage());
typename ImagePatchType::ImageType* image = a.GetImage();
float totalDifference = 0.0f;
if(a.GetStatus() == ImagePatchType::SOURCE_NODE && b.GetStatus() == ImagePatchType::SOURCE_NODE)
{
itk::Offset<2> offsetAToB = b.GetCorner() - a.GetCorner();
// Compare all corresponding pixels and sum their differences
itk::ImageRegionConstIteratorWithIndex<typename ImagePatchType::ImageType> patchAIterator(image, a.GetRegion());
while(!patchAIterator.IsAtEnd())
{
//float difference = fabs(imageIterator.Get() - this->Image->GetPixel(imageIterator.GetIndex() + offsetToOther));
float difference = 0.0f;
for(unsigned int component = 0; component < a.GetImage()->GetNumberOfComponentsPerPixel(); ++component)
{
difference += Weights[component] * fabs(patchAIterator.Get()[component] - image->GetPixel(patchAIterator.GetIndex() + offsetAToB)[component]);
}
totalDifference += difference;
++patchAIterator;
}
}
else if(a.GetStatus() == ImagePatchType::TARGET_NODE || b.GetStatus() == ImagePatchType::TARGET_NODE)
{
const std::vector<itk::Offset<2> >* validOffsets;
if(a.GetStatus() == ImagePatchType::TARGET_NODE)
{
validOffsets = a.GetValidOffsetsAddress();
}
if(b.GetStatus() == ImagePatchType::TARGET_NODE)
{
validOffsets = b.GetValidOffsetsAddress();
}
for(unsigned int i = 0; i < validOffsets->size(); ++i)
{
float difference = 0.0f;
for(unsigned int component = 0; component < a.GetImage()->GetNumberOfComponentsPerPixel(); ++component)
{
difference += Weights[component] * fabs(image->GetPixel(a.GetCorner() + (*validOffsets)[i]) - image->GetPixel(b.GetCorner() + (*validOffsets)[i]));
}
totalDifference += difference;
}
}
else
{
throw std::runtime_error("Patch statuses are not correct!");
}
//std::cout << "Difference: " << totalDifference << std::endl;
return totalDifference;
}