Need help with my Pixel Math mask pleaseeee

[tingting44]

Hi guys im having real trouble getting a useable mask from my L & star mask to create a mask from pixel math that protects my stars and background, if any one can shed any light on to why i am getting a horrible combined mask from pixel math that would be brilliant, thank you kindly

here is a screen shot (top left stack im working on, top right - star mask - bottom right Lum mask)
pixel math by tingting44, on Flickr

and here is the result from pixel math. i type into pixel math under the RGB/k...........    L_mask - star_mask then drag pixel math onto my Lum mask which gives me this
pixel math mask from L & Star mask by tingting44, on Flickr

which is just horrid and i do not know why

[Juan Conejero]

It's difficult to know what happens without the images. Can you upload star_mask and L_mask?

[tingting44]

Thank you for your quick reply Juan!

of course i can mate, ill save the 2 masks now and upload them to dropbox then add the link here

will JPEG's be ok or do you need FITS or TIFF mate

Thank you

[Juan Conejero]

Much better if you upload FITS files. JPEG definitely won't work because of compression artifacts and 8-bit encoding.

[tingting44]

no problem, doing it now Juan

Thank you

edit, just uploading to dropbox now, says one hour, ive included my master stack also incase you need that also

[tingting44]

here is the link to my FITS Juan

https://www.dropbox.com/sh/opqs72ueoo5c60z/AACZHJgBI3ei125aY8FdrtLea?dl=0

[cdesselles]

TingTing44, May I have your permission to download this also?  I'd like to play with it a bit myself.

[Alejandro Tombolini]

Hi, In this processing example you have a second option. There, I used RangeSelection and StarMask to generate one mask to protect background and stars.
However, I think that in your Andromeda would be better a mask that cover more accurately the stars over the galaxy.
Saludos, Alejandro.

[Alejandro Tombolini]

Hi TingTing44, I created a quick example. The information on the starmask obtained with Starmask tool is enhanced with a Structure_map from StarAlignment to include in the mask the stars that are over the galaxy.
hope it helps.

Saludos,
Alejandro.

[tingting44]

Morning cdesselles, of course you can, let me know how you get on

Morning Alejandro..... wow im quite honoured that you have used my images on a tutorial, it looks very excellent! i will be going over it fully probably tomorrow, as i didnt get in till gone 4am this morning, was at my dark site for a good session on M81/M82 and it looks like i have some very nice data

ill let you know how i get on, it is very cool to see my own images in a tutorial

all the best and speak soon, ill let you know how i get on

Martin

[tingting44]

hmm i followed your tutorial to the letter
http://pixinsight.com.ar/en/info/processing-examples/35/mask-background-stars.html

but for some reason its not coming out the same as yours is there anything else you done to the master image before extracting the Lum and star masks as the stars look smaller in the master stack compared to mine? (or it might just be me)

here are the masks i came up with following the tutorial above to exactly the same settings......
https://www.dropbox.com/sh/ob5hr0rgyrcqcvj/AACy70SwU0b6gYNg_Let2W3ta?dl=0

again thank you for taking the time to help little old me

edit, i just tried downloading the xpsm icons on the tutorial at the top of the page but PI is giving me an error message saying "failed"

[Alejandro Tombolini]

Hi Martin,
I did not change anything on the image, just downloaded it.

I am not with PixInsight now to check your masks, I will take a look later.

That is extrange about downloading the file, seem to work for me. I am going to load the icons here.

Saludos, Alejandro.

[tingting44]

ok thank you kindly Alejandro

[cdesselles]

Thanks for the permission TingTing.  I'm going to have me some fun!   

[tingting44]

I hope you do, if you get any decent results please feel free to post them up here