case 8: // Relative Difference
while (!ito.IsAtEnd()) {
if (it1.Get() != 0) ito.Set(PixelTypeDownCast<double, PixelType>(((double)it1.Get()-(double)it2.Get()))/(double)it1.Get());
case 8: // Relative Difference
while (!ito.IsAtEnd()) {
if (it1.Get() != 0) ito.Set(PixelTypeDownCast<double, PixelType>(((double)it1.Get()-(double)it2.Get()))/(double)it1.Get());