>I finally had a chance to process some film shots from this
year's Texas
>Star Party and I wanted to share them and hopefully get
some tips on
>processing dark nebula to remove noise. One image in
particular (Pipe
>Nebula - high res version) has some dark green pixels
spread >throughout the
>dark regions that I assume are some kind of
film grain artifacts???
The green "hot" pixels usually are generated in the scanning process.
They are electronic noise, not grain artifacs.
>Anyone
>know what causes this and how to best process it
out?
Becouse the green channel ussually don't have usefull information, you
can try some radical ways to eliminate them. One of the best process is the
called SCNR (Substractive Channel Noise Reduction). You can read about it in
Juan Conejero's homepage:
www.pleiades-astrophoto.comAlso you can try Juan's software, SGBNR (Selective Gaussian Blur Noise
Reduction), that works very well to reduce the noise due the film's
grain.
Regards,
Carlos Milovic
F.
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