+ // SR: 23/06/2011
+ // We actually use vtkImageReslice which takes the inverse transform
+ // as input. So it seems more correct to inverse the matrix given by
+ // itk::ImageBase< VImageDimension >::GetDirection() than the matrix
+ // in .mat which is indeed the inverse optimized by a typical
+ // affine registration algorithm.
+ // Validated using clitkAffineTransform --transform_grid