Re: [APML] film flat fielding

[Wei-Hao Wang <whwang@gmail.com>]

Hi Scott,

Although I don't have Jerry's book, but from your description I think my 
method is similar to the one you described.  Indeed, sometimes I use it 
too.  I use median filter (instead of bluring) to filter out stars in an image
and subtract the filtered image from the original.  The main difficulty is
on images with lots of stars and nebulas.  For such images, we can
hardly avoid the influence from these stars and nebulas.  This is why I 
need an independent flat to better describe the background. 

Cheers,

Wei-Hao

On Mon, 26 Jul 2004 16:50:13 -0400, Scott Hammonds
<shammonds@creatorsview.com> wrote:
> Interesting Wei-Hao, thanks for posting the article. My question is: Doesn't
> this method pretty much describe the same techniques used in Jerry's book
> when you blur a copy of the image and use the subtract or apply image
> command? I haven't look closely at the method's, and also haven't processed
> an astro photo in a while, but these methods seem similar at quick glance.
> 
> 
> Scott Hammonds
> 
-- 
________________________________________________________________
Wei-Hao Wang  :)

Institute for Astronomy at University of Hawaii

Address:                       
2680 Woodlawn Drive         Personal Website:
Honolulu, HI 96822             http://www.ifa.hawaii.edu/~wang
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