difficult image drift stabilization challenge

[Florin Andrei]

Take a look at this short video:

https://www.youtube.com/watch?v=QcTmFkEIV0s

It is the Sun, captured with a telescope on a tracking mount. It was originally taken as one frame every 1 second over 2.5 hours (nearly 10k frames total) and then sped up to 60 fps - hence the approx 2.5 minutes duration of the video.

The mount was setup during the day. Because of that, polar alignment could not be done accurately (no stars were visible). An approximate alignment was done - as a result, the image is slowly drifting across the frame. Every 30 minutes in real time (30 seconds in this video), I had to make manual corrections. At that point, the image of the Sun jumps suddenly back to center. Then it starts drifting again. I have no idea how to keep the Sun centered for the whole duration of the video.

The telescope tracking software, in theory, could determine the approximate center of the bright disk, and issue corrections to the telescope if the disk center does not coincide with the frame center, and this way it would keep the Sun in the center. However, this technique would not work during an eclipse, because the shape of the disk would change a lot (and it would eventually disappear altogether). So, any software method that does the same (compute the center of the disk, etc) would not work either.

I am somewhat familiar with open source tools such as Avidemux, MeGUI, VirtualDub, etc. I also use Sony Vegas (the cheap version for amateurs, not the pro version). But regular camera shake removal plugins don't seem to work. Youtube's own camera deshaker doesn't work either.

I should add that the original video is roughly at 5k resolution. It's an APS-C sensor in 3:2 format, I've done a little cropping to make it 16:9, but the original MP4 is still more or less 5k. So any processing technique used to stabilize the image must be able to handle such resolutions.

The video comes out of the astronomy software in the SER format (like RAW, but video). I do an initial conversion, using PIPP, to AVI / FMP4; no processing at this step other than format conversion. From there, MeGUI and x264 generate a standard MP4 / AVC video; I also do cropping, white balance, etc in MeGUI (using Avisynth).

Any suggestions are welcome.

[poisondeathray]

Take a look at this short video:

https://www.youtube.com/watch?v=QcTmFkEIV0s

It is the Sun, captured with a telescope on a tracking mount. It was originally taken as one frame every 1 second over 2.5 hours (nearly 10k frames total) and then sped up to 60 fps - hence the approx 2.5 minutes duration of the video.

The mount was setup during the day. Because of that, polar alignment could not be done accurately (no stars were visible). An approximate alignment was done - as a result, the image is slowly drifting across the frame. Every 30 minutes in real time (30 seconds in this video), I had to make manual corrections. At that point, the image of the Sun jumps suddenly back to center. Then it starts drifting again. I have no idea how to keep the Sun centered for the whole duration of the video.

The telescope tracking software, in theory, could determine the approximate center of the bright disk, and issue corrections to the telescope if the disk center does not coincide with the frame center, and this way it would keep the Sun in the center. However, this technique would not work during an eclipse, because the shape of the disk would change a lot (and it would eventually disappear altogether). So, any software method that does the same (compute the center of the disk, etc) would not work either.

I am somewhat familiar with open source tools such as Avidemux, MeGUI, VirtualDub, etc. I also use Sony Vegas (the cheap version for amateurs, not the pro version). But regular camera shake removal plugins don't seem to work. Youtube's own camera deshaker doesn't work either.

I should add that the original video is roughly at 5k resolution. It's an APS-C sensor in 3:2 format, I've done a little cropping to make it 16:9, but the original MP4 is still more or less 5k. So any processing technique used to stabilize the image must be able to handle such resolutions.

The video comes out of the astronomy software in the SER format (like RAW, but video). I do an initial conversion, using PIPP, to AVI / FMP4; no processing at this step other than format conversion. From there, MeGUI and x264 generate a standard MP4 / AVC video; I also do cropping, white balance, etc in MeGUI (using Avisynth).

Any suggestions are welcome.

Did you try deshaker in virtualdub?

If it's mostly like that video , or if that is the video - I would use mocha / after effects . 5K is not a problem if you have enough memory. There are things you can use to make processing for any stabilization go faster , such as crop to the region of interest. That also reduces memory requirements

Because it's mostly a "flat" looking disc - ie. it mostly stays the same appearance and shape (except at the end when sun gets obscured) , this would be an ideal tracker and stabilization method . There are workarounds for the obscured end, but everything else up to that point is pretty much a simple planar track and stabilize. But pretty much any method you choose will require a workaround for the end, because to any software, it will "look" like a different object (to human eyes it no longer looks like the same object either)