Splitting a FITS file into RGB channels.

[Stargazer33]

Hi, I found a really good tutorial on YouTube the other night on processing astro pictures.

The process starts off in DSS saving the resulting stack as a 16 bit FITS file. This is then split into its RGB channels in Nebulosity. Finally the RGB channels are re-combined in Photoshop along with level and curve manipulation.

The thing is I can't really afford the $80 right now to buy Nebulosity. So does anyone know of a free programme that can split a FITS file into its separate RGB channels and save them as separate files?

Thanks.

[carastro]

You should be able to split the tiff file (made by DSS) in photoshop. Go into Channels, highlight the channel you want (turn the eyes off in the other channels. Copy and paste it into a new file.

Carole

[steppenwolf]

FITS Liberator is free and will do what you want. It will load a colour FITS file as three separate 'Planes' and allow you to save them individually.

[JohnC64]

Gimp will play nicely with FITS files (from 2.8 onwards). Just load the FITS File into Gimp, Select the Naxis = 3 Option and press Open and it will load a RGB image. Once it is in GIMP, Select Colors => Components => Decompose. Select the Decompose to Layers Checkbox and press OK. You should now have a greyscale image with three layers in it. Using the layers window(Windows=>Dockable Dialogs=>Layers), just delete the ones you don't want and save the result.

Best of all GIMP is free

Hope this helps

John

Its easier that it sounds from what i wrote above - Honest :-)

[Stargazer33]

Excellent! Thanks for all those suggestions. SGL members come through once again!

[Erquy]

see also links related to some ongoing improvement for GIMP and FIT files

http://libregraphicsworld.org/blog/entry/gimp-team-revitalizes-astrophotography-tools

[Stargazer33]

Looks promising! Thanks. I did wonder if there was an update for GIMP.

[JohnC64]

Damn Just realised that the way I said earlier is overly complicated. Just load the FIT file into Gimp and select the naxis = 0. It will then load all the channels into separate images. :-)

[Stargazer33]

Thanks again John. I need to have another look at GIMP. Unfortunately it can't handle 16 bit files yet but it looks like it is on its way.

[lensman57]

Hi, I found a really good tutorial on YouTube the other night on processing astro pictures.

The process starts off in DSS saving the resulting stack as a 16 bit FITS file. This is then split into its RGB channels in Nebulosity. Finally the RGB channels are re-combined in Photoshop along with level and curve manipulation.

The thing is I can't really afford the $80 right now to buy Nebulosity. So does anyone know of a free programme that can split a FITS file into its separate RGB channels and save them as separate files?

Thanks.

Follow Steve's advice and use Fits Liberator ( free ) to do the job, anything free from  NASA can't be bad.

A.G

[Stargazer33]

Ah! Thanks A.G. I didn't realise that I had to change the image data setting (plane 1, 2 & 3) at the top of the window to save each colour channel. That makes more sense now.

Thanks again.

[bronmw]

FITS Liberator is free and will do what you want. It will load a colour FITS file as three separate 'Planes' and allow you to save them individually.

Just to clarify, plane 1 = red! plane 2 = green! and plane 3 = blue? I thought the DSS FITS file was used to create luminance layer.

So how do I go about creating a luminance layer from DSS?