Archived posting to the Leica Users Group, 1998/04/23

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Subject: Re: [Leica] off-topic: Scanner's noise and depth
Date: Thu, 23 Apr 1998 11:40:33 +0200

There has been a question concerning translation of some scanner related
stuff. This led to some misunderstandings of the notions of 'noise' and
'depth' since it was by far not clear what was meant. I dug in my small
archive and found the following terms of interest

Bruce R Slomovitz <> writes:
     > Tiefenzeichnung means something like the way it draws or shows depth.
'Depth' or sometimes even (erroneously) 'depth of field' means just shadow
detail. The possibility to extract from underexposed slides a wonderful
print. Many scanners seem to have problems here. 
Sometimes it is something like colour saturation, which is a similar topic
concerning a single colour

     > Rauschen could mean a noise or murmur or it could mean interference
     > (i.e.  electrical).

The notion of noise comes from the times when we still listened to the
radio. Noise was all the things we could hear but which noone produced on the
other side of the non existant wire.

When TV came up noise got the meaning of snow in the picture. Strongest to be
seen if no channel at all is selected.

With scanners noise got a similar, yet better defined meaning: 
Given a monochrome area, some pixels still differ in colour. The maximum
difference between single pixels in the area is the noise we are talking about
in this context.