Although I do understand why this balancing of channels is done: but is it not just physics within the target which "tells me" in the data that the, say, H-alpha emission is "much " stronger, than, say, S[II] emission.?
Well, a SHO image is, fundamentally, about aesthetics. The intensity differences between the channels can be huge, and if you treat them with the same scaling you won't see much. The processing is largely about seeing what elements are where, not how much of them there is. From a science standpoint, SHO images help us get an initial sense of structure, but any actual science is conducted on the individual channels, not on the SHO composite. (Likewise for any narrowband data composited into some kind of RGB image.)
Isn't all narrowband processing for aesthetic reasons? Unless you are working on scientific research, all AP is for aesthetic reasons any way.
My image processing is largely about aesthetics, although curiosity naturally leads me to understanding what the data actually represents. But I'd never interest other people in deep space if I only presented scientifically-accurate images that are overwhelmingly green in the SHO palette. A palette to me is what it is to other artists; a set of colours to describe an object. I'm quite happy to use artistic licence to show where the different emissions are coming from. It's an extension of stretching an image luminance to reveal hidden detail within the shadows. This NB normalisation process is in effect just a form of colour stretching.
Not to mention that the physics behind analyzing narrowband data is non-trivial. For instance, equal intensities of H-alpha and [O III] do not mean you have equal amounts or densities of H and O. The intensity is determined by other factors, such as the nature and sources of the ionizing radiation, the quantum details of the specific transitions, and other factors, as well. So the same thing that results in a good aesthetic result actually makes the final image more scientifically useful, as well, by letting us see the distributions of the different elements.
It's a process, not a script. The repository is https://www.cosmicphotons.com/pi-modules/narrowbandnormalization/ and both the process and the repository work just fine with the latest PI.
My bad. I'm not sure what the issue was, but I had to reset/remove all the depository links and re-add them, I left out some that I no longer use. It's back on the process list.
That normally happens when you try to access the link directly via your web browser. You need to copy the link to your repository list and then check for updates. Did you do this?
Glad you got it working!
Looks to be down at the moment. I'm sure it's a transient issue, maybe site maintenance. Check back a little later.
Thanks for reporting this. There is currently a hardware issue that my hosting provider is working to resolve. I am sorry for the inconvenience - hopefully they can resolve without too much delay.
This issue is now resolved.
