Author Topic: Morphological Transformation (MT)  (Read 5547 times)

Offline Nigel Ball

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Morphological Transformation (MT)
« on: 2010 September 17 08:22:26 »
I've been using MT to reduce star sizes and hence enhance the nebula - particulalry for my wide field Veil shots I'm working on wheer there are a lot of stars 30 min subs in Ha and OIII)

Some of my old images have elongated stars in the the corners (sometimes only one corner). I was wondering if I can use MT to correct this elongation but only in one corner. The Star Mask seems to cover the whole of the image.

Thanks

Nigel
Nigel Ball
Nantwich, Cheshire, United Kingdom

Takahashi FSQ-106 at f/8, f/5 and f/3.6 on AP900, Nikon 28 mm and 180mm f/2.8
SBIG STL-11000M, Astrodon LRGB, 5nm Ha
ST-10XME, Astrodon HaLRGB
www.nigelaball.com

Offline Enzo De Bernardini

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Re: Morphological Transformation (MT)
« Reply #1 on: 2010 September 17 09:18:50 »
I learned this trick from Juan, of course  ;)

You can use PixelMath to create a gradient image, and use them as a mask. I attached a screenshot and the PM process icon (right click, Process Icons > Load Process Icons to open it). In this example I create an greyscale image of 800x600 px, with a gradient from bottom right and 800 px radius. You can modify this variables in the Symbols field (cx, cy, r) to create you own mask.

I hope it helps.

Enzo.

Offline Nigel Ball

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Re: Morphological Transformation (MT)
« Reply #2 on: 2010 September 17 09:44:15 »
Thanks Enzo

This is very helpful to me  :D

Nigel
Nigel Ball
Nantwich, Cheshire, United Kingdom

Takahashi FSQ-106 at f/8, f/5 and f/3.6 on AP900, Nikon 28 mm and 180mm f/2.8
SBIG STL-11000M, Astrodon LRGB, 5nm Ha
ST-10XME, Astrodon HaLRGB
www.nigelaball.com

Offline Niall Saunders

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Re: Morphological Transformation (MT)
« Reply #3 on: 2010 September 22 07:05:43 »
Hi all,

For those of you who perhaps didn't see this thread earlier, there is an excellent reply from Juan about creating 'clever' area selection masks:

http://pixinsight.com/forum/index.php?topic=2165.0

Hope this helps
Cheers,
Niall Saunders
Clinterty Observatories
Aberdeen, UK

Altair Astro GSO 10" f/8 Ritchey Chrétien CF OTA on EQ8 mount with homebrew 3D Balance and Pier
Moonfish ED80 APO & Celestron Omni XLT 120
QHY10 CCD & QHY5L-II Colour
9mm TS-OAG and Meade DSI-IIC