Re: filmscanners: GEM

[Arthur Entlich <artistic@ampsc.com>]

Norman Quinn wrote:

>  
> 
>     
>     I was considering trading up from my Artixscan 4000 (SS4000 clone) to a
>     Nikon because I'm sick of removing dust specks, the Nikon was said to be
>     sharper with better shadow performance and faster, not to mention 
>     GEM and
>     ROC.
>     
>      
>     
>     Sorry, but for those without this tool what is GEM and ROC?
>     
>      
>     

As you probably know, the company Applied Science Fiction has at least 
three products for scanning use.  These are the components of dICE cube.

The one most people know, and the one which arrived on the scene first 
is dICE, which is a method of reducing the visible defects like dust, 
dirt, mold, scratches, fingerprints, etc.  This process requires that 
there be an infra-red scan channel as part of the hardware, plus some 
firmware and software to work.

GEM and ROC do not require hardware, but have to be "tuned" to the 
hardware they are used with.  So, in theory, any scanner could have GEM 
and ROC regardless of the hardware,  but it requires that Applied 
Science Fiction be hired to make the profiles, and that the scanner 
company pay a licensing fee to them.

Without getting into the acronyms, which I don't exactly recall, GEM is 
a software process which helps to eliminate the appearance of grain, 
without significantly softening the image, and ROC (return of color - 
that one I remember) is a method of analyzing the image color channels, 
recognizing the type of film emulsion, and then, again via software, 
adjusting the R, G and B levels to add back the expected fading or loss 
of color of some types of films to make it look more like the film prior 
to any fading.

Art