Newbie: Improving processed images

Software Siril
1

Hi all, forgive the soon-to-be-obvious question.

I am using Astrowl as an easy EAA supplement to visual observing. Astrowl can internally stack images, create and apply a dark frame (only) and apply various filters. It produces a .PNG file of around 17MB as the end product.

I am new to imaging and to Siril, but I’d like to improve my Astrowl-produced images with it. In looking at the Siril tutorials, I’m not sure where to start - after the preprocessing scripts I assume, but beyond that I could use some guidance. I’m using Siril on Ubuntu 24.04 LTS. Any assistance welcomed!

2

Hello.
First of all, what is the bit-depth of your png image? If it’s 8-bit, I don’t think there’s anything to do with Siril because all the editing work will already have been done.

3

Thanks for the quick reply. I’ll have to find out - and hope for the best!

4

@lock042 , it looks like it’s a PNG24, but bit depth is 8:

$ file Y2025M6D17_11521_SadrStack2WS.png
Y2025M6D17_11521_SadrStack2WS.png: PNG image data, 3200 x 1800, 8-bit/color RGB, non-interlaced

5

So do not expect making something better. You can play with the curves, on gimp. But that’s all.

6

Sigh. Hoping for the moon … thanks for the help.