[vtkusers] vtkImageGradient??

[Wesley Smith]

vtkImageGradient outputs a vtkImageData.

gradient = vtkImageGradient::new();
vtkImageData * data = gradient->GetOutput();

int *dim = data->GetDimensions(); /// program crashes at this line
when imagegradient passes data to image data it doesn't set scalar values
or create appropriate data fields.

All I need to do is get the scalar gradient values and assign them as vectors to
an image data.
Any experience with vtkImageGradient would help.
Thanks