[itk-python] BlockMatchingImageFilter usage problem

Engineering
1

Hello everyone, I am trying to use BlockMatchingImageFilter to do block matching.
I refered to the c++ example match feature points (https://itk.org/Doxygen/html/SphinxExamples_2src_2Registration_2Common_2MatchFeaturePoints_2Code_8cxx-example.html#_a1) and wrote the following codes,

Dimension = 2
CoordType = itk.F
PointSetType = itk.PointSet[CoordType, Dimension]

pointSet = PointSetType.New()
points = pointSet.GetPoints()

# Create points
point = itk.Point[CoordType,Dimension]()
point[0] = 40
point[1] = 65
points.InsertElement(0, point)

# read images 
PixelType = itk.F
n = 200
path_tr = '../training'
name = '_2CH_ES'
sample = 'patient'+str(n).zfill(4)+'/patient'+str(n).zfill(4)+name+'.mhd'
img_es = itk.imread(os.path.join(path_tr,sample),PixelType)

name = '_2CH_ED'
sample = 'patient'+str(n).zfill(4)+'/patient'+str(n).zfill(4)+name+'.mhd'
img_ed = itk.imread(os.path.join(path_tr,sample),PixelType)

ImageType = itk.Image[PixelType,3]

# block matching 
block_filter = itk.BlockMatchingImageFilter[ImageType].New()
block_filter.SetFixedImage(img_ed)
block_filter.SetMovingImage(img_es)
block_filter.SetFeaturePoints(points)
block_filter.UpdateLargestPossibleRegion()

Error

I got an error : in method ‘itkBlockMatchingImageFilterIF3_SetFeaturePoints’, argument 2 of type ‘itkPointSetMD33STMD3333FFMD33 const *’. Does anyone know how to make the pointset type to be MD33STMD3333FFMD33??

Thank you for your help!!!

2

Did you try itk.D? doubles are more commonly used for everything else except pixel type.

3

Hello! Thank you for your reply!
Yes, I have tried the itk.D and i still got the same error.
I used help() function to check the type of arguments in Blockmatchingfilter and i got:

Help on itkBlockMatchingImageFilterIF3 in module itkBlockMatchingImageFilterPython object:
class itkBlockMatchingImageFilterIF3(itkBlockMatchingImageFilterIF3_Superclass)
| Computes displacements of given points from a fixed image in a
| floating image.
| …
| …
| …
| SetFeaturePoints = itkBlockMatchingImageFilterIF3_SetFeaturePoints(…)
| itkBlockMatchingImageFilterIF3_SetFeaturePoints(itkBlockMatchingImageFilterIF3 self, itkPointSetMD33STMD3333FFMD33 _arg)
|
| SetFixedImage = itkBlockMatchingImageFilterIF3_SetFixedImage(…)
| itkBlockMatchingImageFilterIF3_SetFixedImage(itkBlockMatchingImageFilterIF3 self, itkImageF3 _arg)
|
| SetMovingImage = itkBlockMatchingImageFilterIF3_SetMovingImage(…)
| itkBlockMatchingImageFilterIF3_SetMovingImage(itkBlockMatchingImageFilterIF3 self, itkImageF3 _arg)
| …

I know that itkBlockMatchingImageFilterIF3 should be an image object of float type and with dimension 3, but i am totally lost by the definition of itkPointSetMD33STMD3333FFMD33.
Do you have any idea what does it mean? How could i define the pointset object?
( In the c++ example, the pointset object was defined as following

using PointSetType = BlockMatchingImageFilterType::FeaturePointsType;
using PointType = PointSetType::PointType;
using PointsContainerPointer = PointSetType::PointsContainerPointer;
PointSetType::Pointer pointSet = PointSetType::New();
PointsContainerPointer points = pointSet->GetPoints();

Thank you very much!

4

I got the type of pointset needed in this filter

itk::PointSet<itk::Matrix<double, 3u, 3u>, 3u, itk::DefaultStaticMeshTraits<itk::Matrix<double, 3u, 3u>3u, 3u, float, float, itk::Matrix<double, 3u, 3u> > >

This is quite complicated…

5

I remember there was a problem with wrapping mesh traits, but I don’t know whether that has been fixed meanwhile. @matt.mccormick is BlockMatchingImageFilter's wrapping supposed to work?

6

These classes squeaked past the mesh simplification of ITK 5.0 – I’ll see if we can improve on that.

These feature points are meant to be generated by the itk.MaskFeaturePointSelectionFilter as described in the corresponding article.

1 Like
7

This was addressed here: