Test of GEM on a Nikon LS-4000 with NikonScan 3.1.2
Color management is turned off.

Images are available as png, jpg, and unmodified original tiff (-orig.tif)

I scanned the most grainy film I ever used: "Kodak 5110 EKTAR 1000-1".
Unfortunately, the film was quite badly treated by the lab as is shown
in a scan without ice:

none.png

The following is a scan with ICE set to 'normal' and GEM set to zero (off):

ngem0.png

For some reason, NikonScan does not apply gamma correction when GEM (or ROC)
is on, and color management is off. I applied a gamma of 2.0 in 
PhotoShop 5.0 LE before continuing.

ngem1.png
ngem2.png
ngem3.png
ngem4.png

The number corresponds to the 'amount' of GEM.

Finally, I applied a small amount of Gaussian blur (radius 1.5) to the image
without GEM:

ngem0-g15.png

Bart van der Wolf provided me with an image that has been processed by
Neat Image (http://www.neatimage.com/). It looks like Neat Image is very
effective.

ngem0-NI.png