[vtkusers] GetCenter of vtkImageData - a possible bug?

[John Drescher]

> I have a nifti image that has these features below:
>
>      Dimensions : {301, 370, 316}
>      Origin : {75, 107, -69.5}
>      Spacing : {0.5, 0.5, 0.5}
>
> I want to get center world point of the image. When I use GetCenter method
> of vtkImageData for this purpose, I get {150, 199.25, 9.25}. However, I
> suspected that it seems a bit wrong. And then I tried to calculate the
> center point on my own like below:
>
>      double origin[3], spacing[3], center[3];
>      int dimensions[3];
>
>      imageData->GetOrigin(origin);
>      imageData->GetSpacing(spacing);
>      imageData->GetDimensions(dimensions);
>
>      for(int i = 0; i < 3; i++)
>      {
>          center[i] = origin[i] + ((dimensions[i] / 2) * spacing[i]);
>      }
>
> and center world point becomes {150, 199.5, 9.5}. So which result is true?
> My calculation or GetCenter method?
>

Should dimensions be a double in your calculation instead of int?

John