Image Gradient filter loses origin and spacing information

When you apply the Gradient filter (vtkImageGradient under the covers), the resulting image data set does not have its origin and spacing properly set. Instead, they are set to their defaults, which causes the result to potentially be translated and scaled.

To replicate, do the following.

1. Open disk_out_ref.ex2. Load all variables. Apply.
2. Add Resample To Image filter. Apply.
3. Add the Gradient filter. Apply.
4. Turn the visibility of the Resample To Imagefilter back on.

You will see that the outline of the Gradient filter does not match its input. It is much larger, square, and off center. If you look in the information tab, you will see that, unlike its input, its bounds match its extents because the origin and spacing were not set correctly.

This problem was reported on discourse.