New Feature : Planetary Live Stacking

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New Feature : Planetary Live Stacking

#1

Post by admin »

Planetary imaging has always been a two stage or even three stage process - first capture videos of thousands of frames, then process those videos through your favourite stacking program, and then quite likely take the resulting image into yet another application for sharpening. This new update to SharpCap lets all of that happen live while you are observing!

Here's what a typical video frame might look like when capturing Jupiter
Capture_00001_WithDisplayStretch.jpg
Capture_00001_WithDisplayStretch.jpg (54.32 KiB) Viewed 531423 times
And this is what you might get if you let SharpCap stack about 1000 similar frames and then apply sharpening and a bit of a saturation boost (all done in SharpCap)
processed.jpg
processed.jpg (107.65 KiB) Viewed 531423 times
Getting Started

Getting started is really simple - once you have your planet in view, activate the new 'Live Planetary Stacking/Enhancement' tool. The important things to adjust are:
  • Camera ROI - to keep things from being slow, put the camera into ROI mode with not much more than the planet in the ROI area. Alternatively, you can use the Selection Area tool in the toolbar to draw a selection box around the part of a larger image to process
  • The 'Target Stack Length' - this is how many frames SharpCap will try to stack together - obviously the stack will start much shorter and be noisy, but the noise will drop as more frames are added
  • The Wavelet Sharpening sliders and colour adjustments - increasing wavelet levels 1, 2 and 3 is a good start for sharpening the image.
Capture.JPG
Capture.JPG (54.27 KiB) Viewed 531423 times
Saving your Images

You can save the current processed image as a PNG file (there's also a timelapse option to save a processed frame every second to a video file), however there are other possible uses of this tool from outreach events to making fine focus adjustments while watching the stacked, sharpened image to see what effect they are having. There is also a basic filtering option to only include the best 25% of frames received from the camera in the stack.

Testing on existing saved SER files

If the weather is not co-operating for trying this feature out, you can use 'Test Camera 2 (High Speed)', then choose the 'Browse' button to browse for a sample image in the 'Testing Controls' area. As well as choosing still images, you can select an existing SER file to make SharpCap load and play that file (on repeat) in the test camera. Any existing SER video of one of the planets should be good for testing.

Will it be as good as AutoStakkert!/Registax/PlanetarySystemStacker?

It's obvious to ask the question 'Is this going to be as good as stacking a video in AS!3 or PlanetarySystemStacker or Registax?' The simple answer is no - it's not going to be quite as good as a separate stacking program for reasons including:
  • Only a single alignment point is used to stabilize the video, rather than multiple alignment points with most stacking applications
  • Filtering on frame quality is not as effective when working on a frame-by-frame basis rather than being able to read all the frames at once and then decide which to choose
  • Some calculations have been designed for high speed rather than to get the very best final quality to allow the process to run on a live video stream
  • The technique uses a simplified (exponential decay) stacking system to avoid holding hundreds or thousands of frames in memory
Hopefully further updates will improve some of the limitations, but some are fundamental to the live processing approach. So, the best thing to do is to use this tool but to also capture videos for later processing for the very best image quality. Note that you can capture videos while using this tool and you will get the individual frames from the camera saved, not the processed images you see on screen.

Other things to know...
  • You will need a fairly fast PC to get the best results from this tool - performance is faster when working on smaller images, so use ROI or selection area too
  • This is a SharpCap Pro feature - if you don't have a SharpCap Pro license then you can try it out without being able to save (you will also get a watermark across the on-screen image)
  • A longer stack length will give less noise and allow stronger sharpening to be used. However, long stack lengths will respond less quickly to changes (focus, seeing changes, rotation).
  • The exponential decay stacking being used means that older frames have a weaker contribution to the stack than newer ones. A 900 frame stack at 30fps will have about 63% of the data coming from the last 30 second, about 23% from between 30s and 60s ago, about 8.5% from between 60s and 90s ago and about 5% from longer ago than 90s.
One last thing...

Finally, I need to say a massive thank you to Mike (@Borodog) who persuaded me to give this a try and who has been chief tester and feedback generator over the last week or so :)

cheers,

Robin
Borodog
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Re: New Feature : Planetary Live Stacking

#2

Post by Borodog »

Cannot thank you enough Robin for implementing this. It is amazing. For the first time my wife was actually impressed with Jupiter as it appeared live on the screen during capture.
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Re: New Feature : Planetary Live Stacking

#3

Post by Borodog »

I have some videos of the tool in action last night but it may be a while before I get them uploaded the Youtube and posted here.
kaymann
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Re: New Feature : Planetary Live Stacking

#4

Post by kaymann »

Any plans to update the manual with SharpPlanet and SharpSolve and maybe even a section on SharpCone?

And I should have given you thanks for such a great feature as I was wondering lately if it was possible!!!
Last edited by kaymann on Mon Nov 20, 2023 6:11 pm, edited 1 time in total.
PeterC65
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Re: New Feature : Planetary Live Stacking

#5

Post by PeterC65 »

Excellent new! I've been hoping you might add a feature like this for ages. It should make observing planets via EAA possible at last.
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Re: New Feature : Planetary Live Stacking

#6

Post by PeterC65 »

I'm trying the new tool with a SER file of Mars captured early this year. Not the best planet to use I know, but unfortunately I haven't saved any captures of Jupiter or Saturn.
Anyway, the Live Planetary Stacking feature doesn't seem to be working for me. I'm just seeing the original SER file, albeit with the planet's disc stabilised. The Display Update Rate is showing 0.0. When I use the built in High Speed camera test image of Jupiter and add some offset, seeing, and noise, it seems to work fine, and the Display Update Rate equals the Frame Stacking Rate.
Any suggestions? Or do I just need to wait for a clear night to get a proper look at Jupiter or Saturn?
Borodog
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Re: New Feature : Planetary Live Stacking

#7

Post by Borodog »

Anybody who want to test this without waiting for clear dark skies is welcome to use these SERs. These are the ones I sent to Dr. Glover for development. 1100 Edge HD, one is 640 square at f/10, one 800 square at f/13.8.

https://drive.google.com/file/d/1xrHFaR ... drive_link

Just set your camera to Test Camera 2 (High Speed) and Browse to the SER file in the panel at the right.

Screenshot of live testing last night. Seeing was mediocre. Note that the interface has already changed a bit from this prototype.
Planet Stacking 2_small.png
Planet Stacking 2_small.png (220.35 KiB) Viewed 531074 times
Thanks again, Dr. Glover!
Last edited by Borodog on Mon Nov 20, 2023 6:53 pm, edited 1 time in total.
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Re: New Feature : Planetary Live Stacking

#8

Post by admin »

PeterC65 wrote: Mon Nov 20, 2023 5:58 pm I'm trying the new tool with a SER file of Mars captured early this year. Not the best planet to use I know, but unfortunately I haven't saved any captures of Jupiter or Saturn.
Anyway, the Live Planetary Stacking feature doesn't seem to be working for me. I'm just seeing the original SER file, albeit with the planet's disc stabilised. The Display Update Rate is showing 0.0. When I use the built in High Speed camera test image of Jupiter and add some offset, seeing, and noise, it seems to work fine, and the Display Update Rate equals the Frame Stacking Rate.
Any suggestions? Or do I just need to wait for a clear night to get a proper look at Jupiter or Saturn?
Did you turn up some of the levels in the wavelet sharpening section? They start at default (no sharpening).

cheers,

Robin
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Re: New Feature : Planetary Live Stacking

#9

Post by PeterC65 »

[quote=admin post_id=39496 time=1700505278 user_id=2]
Did you turn up some of the levels in the wavelet sharpening section? They start at default (no sharpening).
[/quote]
I've tried moving the sharpening controls and they have no effect on what I see. I set them over to the right which should completely mess up the image but nothing happened. It looks like I'm just seeing the original SER file but with disc stabilisation. I'm downloading the sample file that Borodog posted but that will take a while with my broadband!
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Re: New Feature : Planetary Live Stacking

#10

Post by Borodog »

Video of the tool in action last night in mediocre seeing:

https://youtu.be/7tPfolaIVGU

Again, the interface has already changed a little bit from the prototype you see here.
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