I added a new feature to KStars' beta software called Image Overlays, and am inviting you to try it out / test it before the next stable release.

You can read about it in the KStars Handbook. The pdf section on it can be found here docs.kde.org/trunk5/en/kstars/kstars/kstars.pdf#imageOverlays
or here in html docs.kde.org/trunk5/en/kstars/kstars/imageOverlays.html

A quick summary is that you can take sky images you've created, and overlay them onto the SkyMap--sort of a personal sky catalog. See the image below for a visual description.

It would be best to read the 2 pages in the manual, but a quick summary is you
- Start with one or more sky images you've created (e.g. jpg),
- Place them in the imageOverlays directory (e.g. on Linux that would be ~/.local/share/kstars/imageOverlays).
- Then you start KStars. (It only checks for new images on startup).
- Then you go to the KStars Settings menu and find the Image Overlays tab.
- Find your new images on the table there and use the UI to plate solve them (since there is no header information available from the finished image). You can also manually input that information.
- All successfully solved (or info manually entered) images should now be visible and accurately placed on the SkyMap.

Please feedback any issues or suggestions,
Hy

Wow... This is so cool. Thank you, Hy!

BTW, I'm trying out an interesting use case for this the next time my skies are clear.

I haven't done any mosaics yet, so I thought I'd try one, however, it is tricky to frame this mosaic, as my object (the Burst Bubble nebula) really doesn't show up much in the HiPS overlays or on the SkyMap.
So, I took a screenshot of a nice version of the Burst Bubble nebula from astrobin, and added that, temporarily, as an image overlay on my system--it plate-solved well. I then ran the mosaic planner tool, and now I clearly see the nebula and can frame it the way I want.
Hy

Wow, i try tomorrow.
Ettore

It's immediately clear this is an extremely useful feature. Thanks a lot, Hy!

Absolutely cool feature Hy!

One suggestion would be a toolbar button to easily switch the overlay on and off.

I tried - it worked beautifully!
In fact, I was thinking about this just a few days ago - it would be nice to overlay my images over KStars...
And here we go - it's available, thanks to Hy.
This is really helpful for framing/mosaics.

Thanks!

Peter: I put in a change to add a menu option in the View menu to toggle on/off image overlays. That comes with a keyboard shortcut, shift-control-o, so that should make it very easy to enable/disable it.
invent.kde.org/education/kstars/-/merge_requests/978

All: FWIW, I also fixed a bug yesterday, so anyone testing should probably upgrade to the latest version.
invent.kde.org/education/kstars/-/merge_requests/977

Hy

Cool feature to use instead of DSS overlay. It would be a nice feature if it could open files and autostretch them as there is better chance of platesolving such images. Also does it support FITS files and if so can it make use of the metadata?

I tested with one picture (attached) in the overlay folder. No FITS info was provided so it ran a "blind solve". After 30s it timed out. Unfortunately the process only terminated on one core with 12 or so cores remaining 100% busy. I had to terminate the process manually.

I had success on other images with the "singlethreadsolving" option activated. Some imaged solved OK, others timed out but when that happened, the single process was terminated correctly.

Alfred,

Thanks for testing. FWIW, I just tried your image.

With the default blind solve, I also timed out after 30s -- though all processes ended (I used the Default profile which should have multiple threads solving). I don't know why the processes weren't terminated after timeout. That was a bug that was in the previous release, but should be fixed if you're testing image overlays. Perhaps it would have terminated after a little longer wait? I don't know the internals of the Qt threading abort mechanism.

I then manually entered the rough coordinates for NGC 7000 in the table for your image: RA=21h, DEC=44 30, and it solved for me in ~10s, again using the default profile.
Solver success in 9.7s: RA 314.55 DEC 44.52 Scale 11.29 Angle 151.15
See image below.

Note, it never gets any header info from the image file--I'm assuming that users will be putting "finished images" into the overlays which as far as I know won't have this kind of info--so it will always blind solve unless you enter the RA and DEC into the table, and/or put a scale in the table or in the "Default a-s/px" box. I do recommend you put a default scale in, and manually add coordinates for any images you have trouble solving.

Hy

@astromuni It doesn't stretch, I envision people using finished images, which would be already stretched. What use case are you talking about?

It uses QImage doc.qt.io/qt-6/qimage.html to read the image files, so it would support whatever formats that supports. I'd say .jpg is your best bet.