Never said the radiologist would let you throw the info away, but noise
is noise and averaging bits together will (should)
> How do you measure the "just noise" in a 12bit scanner? I'd try to
> generate a perfect analog greyscale and scan that.
Not that I was involved in the q/a program, (it was an M.Sc. project done
at the same time as mime, and I had to use the same scanner for some
radiotherapy films). Roughly their was a test film which had a large number
of squares of different (but uniform) optical density. Roughly a scan was
taken of the film, a template was placed over the image and some statistics
where done on the pixels of the different areas. As far as I understood
the analysis showed that on a uniform area the distribution of the values
in the lower two bits was more or less uniform. The conclusions drawn from
that it must be noise.
JAB.
-- Jonathan A. Buzzard, 34 Kepwell Road, Prudhoe, Email: jab@hex.prestel.co.uk Northumberland. NE42 6PD Tel: +44(0)1661-832195 United Kingdom
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