[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [APML] Re: Vi*g*netting and SGBNR info
Matt,
Of course. The relative importance of noise is inversely proportional to
luminance. For example, there is no noise at all on white areas. However,
in many cases we have to reduce noise on bright (unsaturated) areas. Jay
Pott's Hyakutake image is a very good example. For this image, every
unsaturated region must be denoised with no exceptions. In fact, for many
reasons this is a challenging case that forced us to further develop the
edges protection algorithms built in SGBNR version 1.0.9.
Regards,
______________________________________
Juan Conejero, Pleiades Astrophoto Lab
skycad@ctv.es
http://www.pleiades-astrophoto.com/en.html
At 14:21 23/05/2002 -0400, you wrote:
>At 02:15 PM 5/23/2002, Juan Conejero wrote:
>>...For the Matt's LMC image we used image masks. We found that uniform
>>masks are not appropriate for this case, the main reason being that there
>>is no noise to remove in the brightest areas of the image, especially the
>>bright nebulas: uniform masks "wash" them too much.
>
>Juan,
>
>My understanding is that high-density areas usually don't need as much of
>(or any) grain reduction. In fact, bright areas often benefit from
>sharpening, while dim areas are grainier and benefit most from smoothing.
>Is that right?
>
>Matt
>--
>Matt BenDaniel
>matt@starmatt.com
>http://starmatt.com
>
>
>-- APML Archives at <http://astro.umsystem.edu/apml/> ---
> Unsubscribe at <majordomo@seds.org>
-- APML Archives at <http://astro.umsystem.edu/apml/> ---
Unsubscribe at <majordomo@seds.org>