Re: [APML] Playing with SGBNR

[Juan Conejero <skycad@ctv.es>]

Jeff,

Happy to see you're successfully using our software. I've taken the
freedom to reprocess your original M33 shot with SGBNR. I've found the
following set of parameters to substantially improve your 
image:

Channel-specific Parameters

        

Radius =
1.50 for all the R, G, B channels

        

Histogram
midtones = 0.500 for all the R, G, B channels

        

Histogram
shadows and highlights set up through global auto-levels

Global Mask Parameters

        

Blur mask
disabled

        

Auto-All
Levels

        

        

Shadows
clip = 0.005

        

        

Highlights
clip = 0.700

Global Filter Parameters

        

order =
0.50

        

truncation
= 0.001

        

(matrix
size is 35 for all the R, G, B channels)

Edges Protection

        

Threshold
= 0.190

        

Overdrive
= none (0)

I've tried SGBNR on your "Before SGBNR" JPEG image. If you work
with a significatively greater image you'll probably need to increase the
filter radius value, as well as to enable mask blurring. Maybe you'll
need also to use a slightly different filter order. Let us know how it
goes.

Don't worry too much if SGBNR warns when you open certain TIFF files. The
libtiff library is extremely rigorous (that's one of the reasons for
which we use it) with the TIFF format and some programs generate
improperly constructed TIFF files.

Best regards,
______________________________________
Juan Conejero, Pleiades Astrophoto Lab
skycad@ctv.es
http://www.pleiades-astrophoto.com/en.html

At 21:46 16/03/2002 -0500, you wrote:
> Hey all,
> Rain here in the Ohio Valley:-(  I have been playing with some
> software
> today and printing images.  I must say, I am impressed with
> SGBNR.  I
> have found Neat Image gives me some very odd green boogers. 
> Sometimes
> it is green stars, but other times it is green streaks.  Small,
> but
> there nonetheless.  At first, I thought Neat Image was working
> better
> for me than SGBNR.  But as usual, it was operator error.  After
> walking
> through the guide/help one time, I think I have a little better
> handle
> on the software.  I cranked up the noise on an M33 shot to see how
> SBBNR
> could clean it up.  It is still a little bit over the edge, but I
> think
> SGBNR did a great job on it.  I mainly went with auto
> settings.  I think
> I increased the radius in the red channel a bit.  I did not use
> any
> overdrive.  Sorry for the large files.  I am getting some value
> errors
> when opening .tif files.  Again, probably operator error. 
> Something
> about a value of 1 and the software expecting a value of 3.  I am
> sure
> it will be worked out on my end.  I used .bmp files to start and
> saved
> into .tif.  
> Jeff
>
> Before SGBNR
>
> http://www.astro-photography.com/M33_grain.htm
>
> After
>
> http://www.astro-photography.com/M33_new.htm
>
> Jeff Ball
> www.astro-photography.com
> Ohio Valley Astronomical Society
> www.ovas.org
>
>
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