The Budget Conscious Astronomer: Background Extraction using Gimp
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- Опубліковано 15 кві 2021
- First, let me apologize for the sound of my mouse bouncing around my desk but I wanted to get this done quickly.
Using the free, cross platform software Gimp, I was able to extract the background from an astrophoto provided by Paul Tennant. This technique is fairly fast and the software is free!
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gimp.org
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/ planet_of_mystery - Наука та технологія
Thank you for helping many of us with GIMP, especially old farts like me, though zi started in backyard Astronomy at 8 years old and still enjoying it 69 years later.
Wow that background subtracting blew my mind. THANKS
Wow! As a frustrated beginner in AP this was really helpful! Thank you!
Glad it was helpful! I've been using it with some of my older images and I'm still surprised by how well it works.
That was fantastic. I've been struggling with my backgrounds for months. Many Thanks!!!
Idk. What magic yt employed or which device of mine they spied on but this is the exact video I need.
awesome video
Thank you! I try to keep it simple and low cost.
Thank you
this is a very simple and perfect approach
Great video! Learned a lot and will try this on my images.
Great to hear!
Very nice! Am going to subscribe!
Thanks! I hope to get some new videos posted soon. It's been a very busy summer/early autumn around here.
This is brilliant! thank you so much
You're very welcome! I hope you find this helpful!
Awesome thanks
very interesting!
awsome video worth watching. i learned more from this video then any other
Thank you! That's very nice to hear!
Made my day!
@@planetofmystery4787 very welcome..
Thank you. It was very interesting. Many people would be interested in getting a complex lesson on processing astrophotos from beginning to end through such stages as DeepSkyStacker, SIRIL, Gimp. And, as an ideal, the use of Topaz Denoise and Topaz AI for additional quality improvement ...
I try to stick with open source software but I did recently purchase Topaz Denoise and it's made a big difference as well. I'm hoping to get some new images this summer but the weather hasn't cooperated. If things go well, I hope to do a series from capturing to final processing.
@@planetofmystery4787 Looking forward to it with great interest
Very nice!
Thank you.
thanks man!!!!!!!
that's very simple ！
Blur and Subtract. Now I just feel stupid and need to go back and rework a bunch of images.
No need to feel stupid at all. I've been at this for decades and just kind of stumbled across the idea.
That's because this is a way too simple method to be respectful of your data...
Thank you!
You are most welcome. It's based a bit on work by Nico Carver (Nebula Photos) but I took it a little further with some experimentation.
@@planetofmystery4787 Him and Astrobackyard inspired me :-)
Its an interesting approach. I feel like a lot is missed out on tho. It will give a little bit of copy paste feeling, not so natural. I will try it on some of my stuff some day tho :D
I usually do this in Siril(Also free) but i do some minor stuff in Gimp before last export.
Right direction, but uf, is this a ROUGH manipulation of the data... Especially the blurring including the stars! You'll go under zero (bottom clip) for a lot of pixels this way.
Better to also replace the stars with background color (select by color -> set appropriate thresholds/maybe extend selection by a pixel or two -> bucket fill), or better yet, make the stars black and use the despeckle tool (so you don't seed a strange local gradient), THEN use a blur filter of an appropriate size (dependant on the background gradient size... Don't smooth out the gradient, smooth out noise). Also, don't subtract the background layer a hundred percent, but slightly less; set opacity of subtracted layer to 99 or 98 or so. This way, you'll prevent clipping a bit better. Your galaxies will show up with much whispier arms, instead of suddenly stopping.
However, good news; No need to use GIMP at all for BGE anymore! Siril is great free software that has a sophisticated background extractor. Nico Carver (Nebula Photos on YT) has a nice introductory video on it.
So I just did this on a stacked image of the Lagoon Nebula to practice. It was a pretty noisey pic to start with. I don't have the greatest gear. Everything in the vid worked for me. So I tried another stacked image that was cleaner hoping to get a decent pic. Got to the Gaussian blur and the image turned black. I don't really understand. Both stacked images where the same thing basically. Just one was better quality.
Edit: Never mind. I didn't hit ctrl/shift/a after bucket fill