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ToxMan
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Reference Frame Selection - AutoStakkert2 new
      #5830277 - 04/29/13 01:56 PM

I must have missed something in one of the tutorials...

Like Registax, I scan the video frames for a good quality reference frame for alignment points. But, in Registax 6, you can look at your reference frame in comparison with the frames that show up in the stack, having a better quality. (The first one in the order.) It's an extra step. But, I take the best quality frame from the stack, and re-run the video for a new stack and align.

With AS, I'm moving the slider, looking and scanning frames. Does AS do something similar to R6 that makes it easy to find best frame? If not, I suppose I can use R6 to find it and then run the AVI thru AS2. Any short cuts?

Thanks,

Paul


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astrovienna
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Re: Reference Frame Selection - AutoStakkert2 new [Re: ToxMan]
      #5830475 - 04/29/13 03:10 PM

Paul, I don't think it's really important to have a good frame for the APs. Selecting a good reference frame used to be important for registration, since early Registax versions used the frame you selected as the reference frame. (Now both R6 and AS2 assemble a reference frame for you from your best images.) But for align points, the difference between an average frame and an excellent frame probably doesn't make any difference. Hopefully Emil will chime in here.

Kevin


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RedLionNJ
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Re: Reference Frame Selection - AutoStakkert2 new [Re: astrovienna]
      #5830572 - 04/29/13 03:49 PM

Maybe I'm misunderstanding something in the process here, but when I fire up AutoStakkert and ask it to analyze my video, once it has completed the analysis, the frame it displays is the one with what it considers to be the highest 'quality'. That's then the one I place my APs on.

The positioning of the APs seems to matter a bit more in AutoStakkert than it ever did in Registax, but perhaps that's just due to me not really getting a good grasp on Registax before I switched to (the much faster and more intuitive, at least for me) AutoStakkert.

Grant


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ToxMan
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Re: Reference Frame Selection - AutoStakkert2 new [Re: RedLionNJ]
      #5831332 - 04/29/13 11:21 PM

Great! Thanks for the response, Kevin. I was puzzled and didn't understand the difference between R5 and R6. That helps. I was trying different reference frames for AS2 and not seeing a difference. Now I know why. Cool.

Ya, I have analyzed before APs are applied too, Grant. But, I've tried placing APs and analyzing after. I'm not sure which procedure is correct or better. I am confused by the "analyze" button and it's purpose. Darryl suggested a particular layout of the APs. He uses different sized boxes and multi-APs that spread over the planet in a consistent pattern. And, it totally works. And, I like it. It's repeatable rather than random.

Hope you guys get some great imaging opportunities, soon. Real soon!

Paul


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Kokatha man
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Re: Reference Frame Selection - AutoStakkert2 new [Re: ToxMan]
      #5831601 - 04/30/13 05:42 AM

"Analyse" sorts the frames and orders them using algorithms/methodologies that make contrast etc comparisons of the pixel dispersions etc from the various MAPs regions which is my (very!)bare appreciation Paul: if you run "Analyse" before placing any AP's it will still do a grading/sorting and if I'm cautious of rings artifacts through certain seeing conditions etc I either run "Analyse" with just a few larger MAPs boxes initially to get that frame gradation and then employ my actual MAPs layout/pattern with this much more clearly defined image (good for nailing the Cassini apropos MAPs boxes).....that or just making adjustments to the MAPs on the cleaner image after "Analyse"...

If you do either it's surprising how little is changed re the % quality of the poorest image in whatever stacksize number you select, but of course there might be somewhat different stack permutations - but you'd have to quizz Emil re this...

Of course if you're presented with a particularly "dud" image when you drag & drop the avi into AS!2 it makes sense to do an initial "Analyse" to get something decent to use for your MAPs selections imho...Emil consistently makes a point about keeping in from the edges and lately I've found some MAPs selections can be double-edged swords: they can assist with the aforesaid Cassini as I demo'd in a recent animation here on CN, and I have also placed them around the NPZ's hex outline - but sometimes this causes nicks or splits in the NPZ and edge artifacts on Ring "A" which, by removing said MAPs boxes fixes the problem...


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RedLionNJ
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Re: Reference Frame Selection - AutoStakkert2 new [Re: Kokatha man]
      #5831761 - 04/30/13 08:25 AM

Totally with you guys. Emil posted a "best places to put APs for Saturn" somewhere (I can't locate it on CN, so it may have been on FB). I do hope he chimes in here, as I would *hope* he's the authority on AS!2

I wish I had more time to experiment on GOOD data, as opposed to the mush I've been handed so far this apparition...

Emil? Please?

Grant


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rkayakr
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Re: Reference Frame Selection - AutoStakkert2 new [Re: RedLionNJ]
      #5834118 - 05/01/13 11:14 AM

From:
http://www.astrokraai.nl/software/manual/as2_planet.html

"For Saturn, use manual alignment point placement. Diagonal lines on the rings are not good places for alignment points. Place the alignment point on the rings to include a perpendicular feature like the edge of the planet, or the black space at the tips of the rings."

Bob


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ToxMan
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Re: Reference Frame Selection - AutoStakkert2 new [Re: rkayakr]
      #5834225 - 05/01/13 12:10 PM

Thanks, Bob. Maybe it was serendipitous, but I managed to select APs like the link suggests. The only difference being I use some different sizes on the AP boxes. Got that from Darryl.

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MvZ
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Re: Reference Frame Selection - AutoStakkert2 new [Re: ToxMan]
      #5835826 - 05/02/13 08:57 AM

> But for align points, the difference between an average frame and an excellent frame probably doesn't make any difference. Hopefully Emil will chime in here.

No difference at all. You could select the worst frame and place the APs there, and it will give the exact same result (if the APs are placed in the same location).

The reference frame in AS!2 is actually a stack made from the best frames. The bigger the stack, the better the general shape of the object is (just one frame is always a bit distorted, but averaging many frames gives you a good shape of the target and reduce noise both of which are important). A bit blurry reference stack is usually no problem.

>
Ya, I have analyzed before APs are applied too, Grant. But, I've tried placing APs and analyzing after. I'm not sure which procedure is correct or better. I am confused by the "analyze" button and it's purpose.

For planetary images it doesn't really have a purpose but calculate the quality of the frames and give you an indication about this quality (it generates the quality graph, and orders the frames from high to low). If you switch quality settings, you can analyse again to see if that changes anything (usually the quality graphs are similar between different scales, but especially the smallest gradient 2 can pick up on noise instead of actual details easily).

The order of the frames after analyzing does NOT depend on APs that you might have set, it just shows the overall quality of the frame (as if the entire frame had a huge AP placed onto it!). Each AP actually uses it's own subset of frames anyways, so I decided to just show the global frame quality here (which still gives a decent indication of how many frames you might want to stack).

But for placing APs for planetary recordings it doesn't matter if you do that before or after analyse. If I know I want to stack 50% of the frames with gradient 4 and I'm not interested in checking the ordered frames, I just press stack right away and it takes care of the analysis phase 'behind the scenes'.

For Surface recordings you can only place the APs AFTER analyzing. This is because it will also calculate the maximum area of the recording where the APs can be placed without a problem (it depends on the motion in the recording, if there is a lot of motion, only a small FOV is available to place APs on!)

About the APs on Saturn: try to avoid too small APs placed on the rings EXCEPT on stable locations (right at the edge of the Cassini division for example, or where the rings intersect the planet).


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bunyon
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Re: Reference Frame Selection - AutoStakkert2 [Re: MvZ]
      #5835896 - 05/02/13 09:48 AM

What does the gradient do? I've never looked into that.

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MvZ
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Re: Reference Frame Selection - AutoStakkert2 new [Re: bunyon]
      #5835980 - 05/02/13 10:34 AM

It basically influences the scale of the quality estimator. It ranges from 2 (high quality, low noise, fine details) to 6 (very noisy, coarse scale, details barely visible). 4 usually works just fine. I would use 2 for low magnification and very high quality solar or lunar images, 6 for very noisy images of Saturn in blue light at high magnification.

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Sunspot
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Re: Reference Frame Selection - AutoStakkert2 new [Re: MvZ]
      #5836120 - 05/02/13 11:48 AM Attachment (26 downloads)

Just for my visualization, how does this capture look for placing AP's? Any suggestions for better placed AP's?

Thanks!
Paul


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MvZ
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Re: Reference Frame Selection - AutoStakkert2 new [Re: Sunspot]
      #5836147 - 05/02/13 12:05 PM

Too small, too many, and the gaps in the center is not a good idea at all.

The AP size might be good around the strongest locations (intersection of the rings with planet, and right at the edge of the rings where the Cassini division can be best seen), but the planet definitely needs a few large APs.

For Saturn I use something like this: http://www.astrokraai.nl/software/as2_info/sat_ap.jpg

But just try out different settings, and CAREFULLY compare the results by applying exact same processing settings. Choose APs that are obviously too small or really large, and you get a sense of the effects are.


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ToxMan
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Re: Reference Frame Selection - AutoStakkert2 new [Re: Sunspot]
      #5836167 - 05/02/13 12:16 PM Attachment (22 downloads)

Thanks, Emil. I had a general understanding of the quality graph. Now, I see how I can use it better. And, it is very helpful to me knowing how the gradient function works and it's influence on noise levels.

Your AP selection pattern is similar to what I used to do, Paul. I changed to a different pattern after corresponding with Darryl. But, a slight variation of my own. (I have a feeling we are opening flood gate for screenshots of APs )


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sfugardi
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Re: Reference Frame Selection - AutoStakkert2 new [Re: ToxMan]
      #5836241 - 05/02/13 12:59 PM Attachment (16 downloads)

Guys, I go 65px covering all interesting features, for example this one is 36 points. A lot of overlap and it take awhile to stack 2000 of 7-8000.

Regards,
Steve

PS: I finally stop pre-castrating the videos before AS2


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Sunspot
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Re: Reference Frame Selection - AutoStakkert2 new [Re: MvZ]
      #5836463 - 05/02/13 02:29 PM

Thanks. I'm going to have to try the larger AP's. The attached in that message is not how I normally apply AP's...you would totally freak out if you saw. However, comparing my normal method to that attached image of mine, my normal method produced a much better image. I'll test your suggestion and see how it compares. I hate to hijack the thread, but this line of discussion is very valuable.

Thanks!
Paul


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bunyon
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Re: Reference Frame Selection - AutoStakkert2 new [Re: MvZ]
      #5836496 - 05/02/13 02:42 PM

Thanks, Emil. When I'm back home I'll play with that. You've given some nice tips on alignment boxes, as well.

Quote:

It basically influences the scale of the quality estimator. It ranges from 2 (high quality, low noise, fine details) to 6 (very noisy, coarse scale, details barely visible). 4 usually works just fine. I would use 2 for low magnification and very high quality solar or lunar images, 6 for very noisy images of Saturn in blue light at high magnification.




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ToxMan
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Re: Reference Frame Selection - AutoStakkert2 new [Re: bunyon]
      #5837127 - 05/02/13 07:55 PM

No worries, Paul. This is really helpful...hijack all you want! I've already picked up a few pointers. My screen shot shows 7 APs. But I sometimes throw in a few more that makes 11 or 12 APs total.

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zAmbonii
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Re: Reference Frame Selection - AutoStakkert2 new [Re: ToxMan]
      #5841895 - 05/05/13 03:39 PM Attachment (18 downloads)

Interesting.

I just did a little test to compare between alignment point selections.

I have recently been doing something similar to what Steve had above, using about 30 alignment points, but at 50px size. I just did a stack of the same image using a total of 10 APs. They were similar to what Emil has in his link. The APs at the end of the rings were 100px and the rest were 70px.

Below is the result. The processing was the same on the two (4000 frames stacked out of 9000) and the same wavelets. The wavelets are a bit harsh and I dont like the way the rings look, but the settings show some of the cloud structures a little better.

It may be a little tough to see in this animated .gif, but the run with only 10APs, it looks like the cloud structres are a slight bit more well defined and brighter (look at the bright clouds at meridian about 2/3 the way up)


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