Function ValidateConsistency

Wrapping/Python/mitk/MultiLabelSegmentation.cpp:235–281

Pixel/label consistency scan backing MultiLabelSegmentation.validate(). Group images are always uint16, so the buffer is read directly (no ITK type dispatch). Checks two cases per group: pixel values present in the image but not declared as a label, and labels declared but absent from the pixel data.

// dispatch). Checks two cases per group: pixel values present in the image but
// not declared as a label, and labels declared but absent from the pixel data.
std::vector<std::string> ValidateConsistency(const MultiLabelSegmentation& seg)
{
  std::vector<std::string> warnings;
  const auto n = seg.GetNumberOfGroups();
  for (unsigned int g = 0; g < n; ++g)
  {
    const auto declaredVec = seg.GetLabelValuesByGroup(g);
    const std::set<Label::PixelType> declared(declaredVec.begin(), declaredVec.end());

    std::set<Label::PixelType> present;
    const Image* img = seg.GetGroupImage(g);
    const auto steps = img->GetTimeSteps();
    for (unsigned int t = 0; t < steps; ++t)
    {
      auto imageTimeStep = SelectImageByTimeStep(img, t);
      std::unique_ptr<ImageReadAccessor> acc;
      {
        // The accessor takes the image read lock; release the GIL around its
        // construction, matching AsNumpyAccessor. The buffer scan below touches
        // no Python objects.
        py::gil_scoped_release release;
        acc = std::make_unique<ImageReadAccessor>(imageTimeStep);
      }
      const auto* buf = static_cast<const Label::PixelType*>(acc->GetData());
      const std::size_t count = static_cast<std::size_t>(imageTimeStep->GetDimension(0)) *
                                imageTimeStep->GetDimension(1) * imageTimeStep->GetDimension(2);
      for (std::size_t i = 0; i < count; ++i)
        if (buf[i] != MultiLabelSegmentation::UNLABELED_VALUE)
          present.insert(buf[i]);
    }

    for (auto v : present)
      if (!declared.count(v))
        warnings.push_back("Group " + std::to_string(g) + ": pixel value " +
          std::to_string(v) + " is present in the image but not declared as a label");

    for (auto v : declared)
      if (!present.count(v))
      {
        const auto lbl = seg.GetLabel(v);
        const std::string name = lbl.IsNotNull() ? lbl->GetName() : "?";
        warnings.push_back("Group " + std::to_string(g) + ": label " +
          std::to_string(v) + " ('" + name + "') is declared but not present in the pixel data");
      }
  }
  return warnings;
}

} // anonymous namespace