Re: [APML] van Cittert Deconvolution

["Frank Barrett" <frankb@celestialwonders.com>]

Mike,

Wow! Thanks for going to the trouble of demonstrating this with my image!  I
will definitely make a point to experiment more with the LR algorithm.
-----
Frank Barrett
http://celestialwonders.com

----- Original Message -----
From: Mike Unsold <mike@mlunsold.com>
To: Discussion of Film Astrophotography <astro-photo@seds.org>
Sent: Saturday, March 15, 2003 6:00 PM
Subject: Re: [APML] van Cittert Deconvolution


> Hi Frank,
>
> The noise in the dark regions of your lunar image is from noise
> amplification
> by the Van Cittert deconvolution. This is a drawback with the Van Cittert
> method.
> Other methods have been devised to mitigate noise amplification. The
> following
> image is the result of 40 iterations of an adaptive Richardson-Lucy
> deconvolution
> using a 7x7 Gaussian point spread function. This method has much better
> resistance
> to noise amplification.
>
> http://www.mlunsold.com/examples/Temp/PlatoCompare.jpg
>
> Mike
>
>
> ----- Original Message -----
> From: "Frank Barrett" <frankb@celestialwonders.com>
> To: <astro-photo@seds.org>
> Sent: Saturday, March 15, 2003 4:39 PM
> Subject: [APML] van Cittert Deconvolution
>
>
> > If this is slightly off topic, please forgive me this one indiscretion.
> > There seemed to be some recent interest in deconvolution so I thought I
> > would share some of my early results with this technique.  It's very
> > exciting.
> >
> > After seeing Juan's wonderful mosaic yesterday I went home and cracked
> open
> > a recently acquired book "The Handbook of Astronomical Image Processing"
> > which comes with the AIP4WIN software.  In it I learned of the magic of
> > deconvolution and was pleased to find that the software contains the van
> > Cittert algorithm.  I experimented with this on my first quarter mosaic
> and
> > found that it did crisp things up a bit, but if I went "too" far it
seemed
> > to bring out a lot of noise in the darker regions.  Anyone know how to
> > mitigate this?
> >
> > http://celestialwonders.com/FirstQuarterMosaic.html
> >
> > I also took the opportunity to process a four frame mosaic of the Plato
> > crater region taken at f/20.  Each individual frame is a median combine
of
> > 12 of the best out of 20 frames.  With this I was able to go 250
> iterations
> > with van Cittert deconvolution.  The results just blew me away!  It's
> liked
> > I've discovered a whole new dimension to this hobby!  The page contains
> the
> > raw convoluted image as well as the processed image for comparison.
> >
> > http://celestialwonders.com/Plato.html
> >
> > Comments welcome!
> > -----
> > Frank Barrett
> > http://celestialwonders.com
> >
> >
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> >
>
>
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