Reading a .Nrrd file having 3 dimenisions (X,Y,numSlice) and visualizing them in a sequence.

srivastava.va · June 3, 2021, 9:50pm

Hello, I am just beginning to write code using ITK and have been wondering how to read .Nrrd files. So far I have written this code :

I am not sure how to visualize the 2D slice data that I have stored in the img.
Is there a simpler way to read .nrrd files and visualize them ?

dzenanz · June 3, 2021, 10:04pm

You seem to have correctly read the image. ITK does not do visualization, just reading/processing/writing. For a quick check, you could do std::cout<<img;.

For visualizations, ITK-SNAP (simpler, quicker) or 3D Slicer (more powerful, more complicated).

srivastava.va · June 4, 2021, 1:42pm

Thank you for the prompt response, Dzenanz. On another note is it possible to utilize VTK for visualization of these files ? I came across the class vtkNrrdReader, but unfortunately I couldn’t find any examples.

dzenanz · June 4, 2021, 1:55pm

Yes, VTK is frequently used to visualize images and other things. Both ITK-SNAP and 3D Slicer use VTK for visualization. Here are some examples.

srivastava.va · June 10, 2021, 4:18pm

Thanks Dzenan for your help, meanwhile I was able to write a program to visualize the .nrrd files. But I am getting the following error when I try to build it :

|Error|C2440|‘function-style-cast’: cannot convert from ‘initializer list’ to ‘vtkSmartPointervtkImageMapper3D’

I have attached the file along.
HelloInsight.cpp (5.1 KB)

srivastava.va · June 10, 2021, 5:20pm

I was able to solve the problem by replacing actor->GetMapper->SetInputConnection(color->GetOutputPort()). Anyway, thank you for your help.