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.

I overlaid a bunch of stuff.
From 950mm to 135mm.
All solved fine but I did enter coordinates for each and used 2-SingleThread.
My large 3x3 Sadr mosaic didn't solve so I had to overlay each panel separately.

Really like this new feature : )

In my experience the final images dont work too well when you attempt to platesolve; especially ones that have been compressed using a lossy algorithm like jpg. Hence was thinking that users could upload pre-stretched images and apply an autostretch (I know it may not be as pretty).