How to get voxel coordinates(as in ITK snap ) from vtkimage viewer from mouse click

Question

I am trying to use ITK's region growing algorithm for medical image segmentation. So to put the seedpoint i need exact voxel coordinates of the mouseclick position in my vtkimageviewer. So how can I get those voxel coordinates(as in ITK snap tool) from my vtkimage viewer. Currently I am able to get VTK World Coordinates using pick point picker. Now how to convert this vtk world coordinates to voxel coordinates as in ITK snap tool … Please help me with this information.

Answer 1

You should use ijkIndex = itkImage->TransformPhysicalPointToIndex(worldCoordinates);