Python wrapping for 64-bit double `itk::Mesh` coordinates?

Niels_Dekker · August 5, 2022, 2:53pm

Is there a Python wrapping of itk::Mesh for 64-bit floating point (double) coordinates of its points?

In C++, an itk::Mesh has 32-bit float coordinates by default, but it can be set to 64-bit double by some “mesh traits”:

// 64-bit `double` coordinates
using MeshType = itk::Mesh<int, 2, itk::DefaultStaticMeshTraits<int, 2, 2, double>>;

Could something like that be made possible in Python?

// Possible with itk python wrappings?
mesh = itk.Mesh[itk.D, 2, itk.DefaultStaticMeshTraits[itk.D, 2, 2, itk.D]].New()

dzenanz · August 5, 2022, 3:20pm

@Pranjal_Sahu or @Tom_Birdsong might know. But I doubt this is possible with default Python builds (e.g. PyPI wheels).

Tom_Birdsong · August 5, 2022, 3:29pm

Hi @Niels_Dekker, yes, from what I can tell your proposed implementation is the best way to accomplish this. I do not believe there is are mesh wrappings with double coordinates in the ITK Python wheels at the moment.

Pranjal_Sahu · August 5, 2022, 4:38pm

It can be done. But it’s not present.

github.com

InsightSoftwareConsortium/ITK/blob/master/Modules/Core/Mesh/wrapping/itkMeshBase.wrap#L11


      
          itk_wrap_include("itkDefaultStaticMeshTraits.h")
          itk_wrap_include("itkDefaultDynamicMeshTraits.h")
          
          
UNIQUE(types "${WRAP_ITK_SCALAR};D")
          
          
set(WRAPPER_AUTO_INCLUDE_HEADERS ON)
          
          
itk_wrap_class("itk::Mesh" POINTER)
            foreach(d ${ITK_WRAP_IMAGE_DIMS})
              foreach(t ${types})
                itk_wrap_template("${ITKM_${t}}${d}" "${ITKT_${t}},${d}")
              endforeach()
              itk_wrap_template("A${ITKM_D}${d}" "itk::Array<${ITKT_D}>,${d}")
            endforeach()
          itk_end_wrap_class()
          
          
set(WRAPPER_AUTO_INCLUDE_HEADERS OFF)
          itk_wrap_include("itkCellInterface.h")
          itk_wrap_class("itk::CellTraitsInfo")
            foreach(d ${ITK_WRAP_IMAGE_DIMS})
                itk_wrap_template("${d}${ITKM_F}${ITKM_F}${ITKM_IT}${ITKM_IT}${ITKM_IT}${ITKM_PF${d}}MC${ITKM_IT}${ITKM_PF${d}}"

Probably to keep limited number of options.

Niels_Dekker · August 5, 2022, 9:12pm

@dzenanz @Tom_Birdsong @Pranjal_Sahu Thanks for your useful replies so far.

FYI I would find 64-bit floating point support for a Python itk.Mesh interesting, especially because in Python, the built-in floating point type also corresponds with 64-bit double: sys — System-specific parameters and functions — Python 3.10.6 documentation So supporting double as mesh coordinate type would allow Python users to pass their floating point data to an itk.Mesh in a lossless way.