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OIII RGB Image In Gimp???

Processing OIII Deep Sky
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Dale Penkala avatar
Dale Penkala avatar
Hello All,
I'm  wondering if what I want to do can be done here. I've taken an image with a OSC camera (zwo294) and the same image with an OIII filter.  I would like to add this OIII data to that original image. I know it can be done I'm sure but my brain just isn't following how to do this. And to make things even more difficult I'm using Gimp. I know its very similar to PS so I'm wondering if you PS users could give me the general idea how you would attempt to do this. Maybe I'd be able to that in Gimp once I understand the process.

I've watched several YouTube video's on the HaRGB and have gone thru the steps but my problem becomes trying to keep just the individual channel that is need. When I copy the specific channel I want (say the green channel) I always end up with all 3 channels pasted and I only want to keep the Green channel. 

I've taken the original image and used the "decompose" tool to break the RGB image up into there respective channels but when I go to tell Gimp what color they are the "colorize" option is greyed out so I don't know what else to do to make the  "green channel" truly Green.

I know many are going to tell me to just use PS but I'm really trying not to have to go that route. So any of you that may use Gimp that have figured this out could you please give me some guidance on how to do this. I'm stumped on how to add the OIII data to my image.

Thanks in advance!

Dale
andrea tasselli avatar
andrea tasselli avatar
Frankly even if possible why would you do that? I mean, there are no-cost alternatives to Gimp dedicated to AP and you should really drop Gimp for good and start use those. From my days with Gimp I suggest you use the OIII as an alpha layer for both G and B and use the channel toolbar to operate the blending. The version I used is quite different from the more recent versions so you'd have to look these things up.
Dale Penkala avatar
Dale Penkala avatar
andrea tasselli:
Frankly even if possible why would you do that? I mean, there are no-cost alternatives to Gimp dedicated to AP and you should really drop Gimp for good and start use those. From my days with Gimp I suggest you use the OIII as an alpha layer for both G and B and use the channel toolbar to operate the blending. The version I used is quite different from the more recent versions so you'd have to look these things up.

Thanks Andrea for your reply. I’ll try your suggestion and see if I can get that figured out. I’ve searched out many Gimp tutorials etc.. and quite honestly the things you just suggested haven’t been found, at least by my searches. Believe me I try to figure out these things 1st before I waste peoples time with my petty issues here. We all have images to work on!

If your saying to drop Gimp what other “no-cost alternatives” what do you recommend? 

In all honesty its not the cost factor, its the fact that these are online subscriptions and my internet reliability just isn’t good enough. I’m lucky to just have any internet at all. Very few worthwhile internet companies out in my area so thats more the reason verses cost.

BTW i have Sirerl and I personally don’t find that all that easy to use as many have suggested that is was.

Dale
andrea tasselli avatar
andrea tasselli avatar
Siril is definitely the way to go here unless you want to spend big money on PI and go through the steep learning curve everyone had to.  There are tutorials in their web-site you can learn from or put your files somewhere and I'll look into how this can be done. Basically, you split the RGB image into the RGB components and then register the OIII image to those. Once registered you add OIII to the G and OIII to B. Then you put everything back together and you'll end up with a R(G+OIII)(B+OIII) image, otherwise known as OIII enhanced-RGB.
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Dale Penkala avatar
Dale Penkala avatar
andrea tasselli:
Siril is definitely the way to go here unless you want to spend big money on PI and go through the steep learning curve everyone had to.  There are tutorials in their web-site you can learn from or put your files somewhere and I'll look into how this can be done. Basically, you split the RGB image into the RGB components and then register the OIII image to those. Once registered you add OIII to the G and OIII to B. Then you put everything back together and you'll end up with a R(G+OIII)(B+OIII) image, otherwise known as OIII enhanced-RGB.

Hello Andrea, at this point I’m really not interested in PI, however that’s not to say that at some point I wouldn’t be. As I stated above PI is subscription as well and the fact that I don’t have great internet service I’d be in the same situation with PS.

I’m familiar with the fact I have to do to combining of the OIII to the individual channel’s but again I can’t figure out how to get that done in Gimp. I can use the decompose function to split my image into the 3 channels but to save and name JUST the green channel I can’t seem to get that part to work. I understand the Blue and Green channels would be the OIII locations to be then combined to the original RGB image then blend with the opacity for each layer.

In the meantime I’ll look closer at the Sireil as. Do have it on my computer but I’ve not been successful at even manipulating an image in it.

Thanks!
Dale
Tomas Chylek avatar
Tomas Chylek avatar
Do not decompose into channels but to layers. Then you should be able to assign colors and compose back.

I personally use 294MC with duo band filter and my process is first extract Ha and OIII channels using Astropixelprocessor and the immediately import those into GIMP to compose (I do not compose in APP).
Dale Penkala avatar
Dale Penkala avatar
Tomas Chylek:
Do not decompose into channels but to layers. Then you should be able to assign colors and compose back.

I personally use 294MC with duo band filter and my process is first extract Ha and OIII channels using Astropixelprocessor and the immediately import those into GIMP to compose (I do not compose in APP).

Thanks Tomas! I’ll give this a try! 
Dumb question as I’ve not heard of it but what is Astropixelprocessor? Is this a plugin or a separate program?

Thanks!
Dale
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Tomas Chylek avatar
Tomas Chylek avatar
APP is standalone software alternative to PI:
https://www.astropixelprocessor.com/
Cyril Richard avatar
Cyril Richard avatar
Hello.

Here a tutorial on how to proceed with Siril: https://siril.org/tutorials/rgb_composition/
Dale Penkala avatar
Dale Penkala avatar
Tomas Chylek:
APP is standalone software alternative to PI:
https://www.astropixelprocessor.com/

Thank you Tomas, I’ll take a look at this!

Dale
Dale Penkala avatar
Dale Penkala avatar
Cyril Richard:
Hello.

Here a tutorial on how to proceed with Siril: https://siril.org/tutorials/rgb_composition/

Hello Cyril, Thank you for this. I have attempted to use this program and it never seems to work for me. I did one of my images about a month ago by going with the recommended settings for the image coming out of DSS and it completely messed up DSS to the point that I had to uninstall it and reinstall the software so I have stopped even trying to use is.

When I read this tutorial, I’m not sure if it would work for my application. I use a OSC camera and I shot an image with an l-enhance filter which I’ve already processed and am very pleased with. You can see it here:  https://www.astrobin.com/w0dal8/ I then shot it with my OIII filter (again OSC) and had planned on using just the G & B channels from the stacked image from SharpCap which from what I understand has to be split into its respective channels so that I can choose, work with and save/add to the respective channels of the finished image I want to apply the OIII data to. 

When I 1st found out about Siril I got excited to use it thinking it could help me to do somethings I’ve wanted to do and make it a bit more streamlined but I just haven’t found it to be what I thought it was. I’ve watched tutorials and read several an I just can’t seem to make it work for me I guess so I’ve stayed away. If you think this could allow me to do what I’m wanting to do, I’m open to trying it to add my OIII data to the image. I have so many images I’d like to do the OIII and Ha data to create the final images I’m looking for.

Thanks!
Dale