Method CreateLabelClassMap

Modules/Multilabel/src/mitkLabelSetImageConverter.cpp:458–511

std::pair<mitk::Image::Pointer, mitk::IDToLabelClassNameMapType> mitk::CreateLabelClassMap(const MultiLabelSegmentation* segmentation, MultiLabelSegmentation::GroupIndexType groupID, const MultiLabelSegmentation::LabelValueVectorType& selectedLabels)
{
  if (nullptr == segmentation) mitkThrow() << "Error, cannot create label class map. Passed segmentation is nullptr.";
  if (!segmentation->ExistGroup(groupID)) mitkThrow() << "Error, cannot create label  class map. GroupID is invalid. Invalid ID: " << groupID;

  auto map = mitk::Image::New();

  // map->Initialize(segmentation) does not work here if this label set image has a single slice,
  // since the map would be automatically flattened to a 2-d image, whereas we expect the
  // original dimension of this label set image. Hence, initialize the map more explicitly:
  map->Initialize(MultiLabelSegmentation::GetPixelType(), segmentation->GetDimension(), segmentation->GetDimensions().data());
  map->SetTimeGeometry(segmentation->GetTimeGeometry()->Clone());

  ClearImageBuffer(map);

  // get relevant labels (as intersect of groupLabels and selectedLabels
  auto groupValues = segmentation->GetLabelValuesByGroup(groupID);
  auto relevantDetectLamba = [&selectedLabels](MultiLabelSegmentation::LabelValueVectorType result, MultiLabelSegmentation::LabelValueType element)
    {
      if (std::find(selectedLabels.begin(), selectedLabels.end(), element) != selectedLabels.end())
      {
        result.push_back(element);
      }
      return result;
    };

  auto relevantGroupValues = std::accumulate(groupValues.begin(),
    groupValues.end(),
    MultiLabelSegmentation::LabelValueVectorType(),
    relevantDetectLamba);

  // construct class mapping
  auto classToValueMap = LabelSetImageHelper::SplitLabelValuesByClassName(segmentation, groupID, relevantGroupValues);

  ConstLabelVector destLabels;
  LabelValueMappingVector transferMapping;
  IDToLabelClassNameMapType classLookUp;

  for (const auto& [className, labelValues] : classToValueMap)
  {
    MultiLabelSegmentation::LabelValueType classValue = classLookUp.size() + 1;
    classLookUp.insert(std::make_pair(classValue, className));
    destLabels.push_back(Label::New(classValue, className));
    for (const auto& labelValue : labelValues)
    {
      transferMapping.emplace_back(std::make_pair(labelValue, classValue));
    }
  }

  TransferLabelContent(segmentation->GetGroupImage(groupID), map.GetPointer(),
    destLabels, MultiLabelSegmentation::UNLABELED_VALUE, MultiLabelSegmentation::UNLABELED_VALUE, false, transferMapping, MultiLabelSegmentation::MergeStyle::Replace, MultiLabelSegmentation::OverwriteStyle::IgnoreLocks);

  return std::make_pair(map, classLookUp);
}

std::pair<mitk::Image::Pointer, mitk::IDToLabelClassNameMapType> mitk::CreateLabelClassMap(const MultiLabelSegmentation* segmentation, MultiLabelSegmentation::GroupIndexType groupID)
{