CODEWITHSUNDEEP
pythonvtkcontour
MrPedru22
MrPedru22

Reputation: 1344

Getting region inside contour in VTK

I'm generating a contour in 2D through vtkContourFilter. (see image attached below) Now I would like to get the region that is inside the contour and save it as vtkImageData or something similar that would result in an image just with the data inside the contour. Everything else would be black, just to have the same dimensions as the slice.

enter image description here enter image description here

I don't know how to get the region inside the contour, is there anyway to do it?

This is what I did so far: 

import vtk 

reader = vtk.vtkXMLImageDataReader() 
reader.SetFileName("sample.vti") 
reader.GetOutput().SetUpdateExtentToWholeExtent() 
reader.Update() 

flipYFilter = vtk.vtkImageFlip() 
flipYFilter.SetFilteredAxis(1) 
flipYFilter.SetInput(reader.GetOutput()) 
flipYFilter.Update() 

image = flipYFilter.GetOutput() 

extractSlice = vtk.vtkExtractVOI() 
extractSlice.SetInput(image) 
extractSlice.SetVOI(image.GetExtent()[0], image.GetExtent()[1], \ 
           image.GetExtent()[2], image.GetExtent()[3], \ 
           5, 5) 
extractSlice.SetSampleRate(1, 1, 1) 
extractSlice.Update() 

contour = vtk.vtkContourFilter() 
contour.SetInputConnection(extractSlice.GetOutputPort()) 
contour.SetValue(1,90) 

#How to get the region inside the contour?

Thanks in advance.

Upvotes: 4

Views: 1436

Answers (2)

mirni
mirni

Reputation: 695

You should be able to do this by using vtkPolyDataToImageStencil followed by vtkImageStencil, just like in this example http://www.vtk.org/Wiki/VTK/Examples/Cxx/PolyData/PolyDataContourToImageData

HTH,

Miro

Upvotes: 2

jhoepken
jhoepken

Reputation: 1858

The vtkContourFilter is a - in your case - line representation that does not allow for any "inside/outside" filtering. What you want is the vtk.Threshold

threshold = vtk.Threshold()
threshold.SetInputConnection(extractSlice.GetOutputPort())
threshold.ThresholdRange = [37.35310363769531, 276.8288269042969]

The above code is something out of my head, and the two scalars are the min and max values which you apply the threshold to. Have a look at Paraview, which you can use to assemble your visualization and record everything using the Python tracer. This leaves you with python code that you can then use with normal VTK and python, which is great and exactly what you need. But this way, the prototyping process is way faster, than only with python.

enter image description here

Upvotes: 4

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