PixInsight masking help

[Catanonia]

I really like the local histogram tool, LHE but I want to do it only to a galaxy and not the entire image.

I need a mask. But the only one available is the star mask. I have checked the drop down box in the dialog for structures, but can't quite seem to get a mask around the galaxy.

Would really love the masking preview that you have with the nosie reduction program.

Any help would be greatfully appreciated, especially if it was a simple step by step how to.

[ashworthacca]

I'm really interested in this too. I've been extracting the luminance then applying that as a mask to the image. Not ideal but works reasonably well.

[harry page]

Hi

You can use a luminance mask like the one I use in this video http://www.harrysastroshed.com/saturation.html

Don't forget you can alter the mask with the histogram tool to darken the background and lighten the galaxy areas thus giving more protection to the background and less to the galaxy

A little trick is to do the following

1) create a clone on the image you want a mask for

2) open ACDNR and create a mask using the real time preview

3) close the real time preview

4) leave the real time preview box ticked

5) apply to your clone

you now have a inverted mask which you can now apply to your image and use the invert instruction on the mask tool bar to protect the correct areas

Regards Harry

[ashworthacca]

Excellent Harry...great tip.

[Catanonia]

Hi

You can use a luminance mask like the one I use in this video http://www.harrysastroshed.com/saturation.html

Don't forget you can alter the mask with the histogram tool to darken the background and lighten the galaxy areas thus giving more protection to the background and less to the galaxy

A little trick is to do the following

1) create a clone on the image you want a mask for

2) open ACDNR and create a mask using the real time preview

3) close the real time preview

4) leave the real time preview box ticked

5) apply to your clone

you now have a inverted mask which you can now apply to your image and use the invert instruction on the mask tool bar to protect the correct areas

Regards Harry

Beuatiful, works perfectly. Thanks Harry

[BernieD]

Hi Catanonia,

Every image of the correct size can be used as a mask. In order to isolate the galaxies, I would suggest you to extract the large objects in your image by extracting the wavelets layer of high order. Once the large shapes are extracted, you can refine your image by applying noise reduction, histogram and other treatments. Once you are happy, apply it as a mask.

Hope it helps.

[swag72]

How do you guys learn all of this stuff?!! I am in awe of your skills and knowledge