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11th January 2020, 17:05 | #41 | Link |
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I'm referencing an idea of redfordxx
https://forum.doom9.org/showthread.p...61#post1894961 to enhance analysis phase of orig Deshaker. On my attempts to understand the projection shekh uses in his filter for accounting FOV... and with my idea that it would be better to account FOV BEFORE analysing phase... https://forum.doom9.org/showthread.php?t=177335 ... I would like to propose to use exactly the "simple trig" that shekh is using for his phase two for pre analysis. Example If you have a movie with large FOV (say 90++) project it "flat" (simple trig). ==> Will make it a pincushion und use that for analysis phase. Both ideas should give more and better (wrt FOV) matchings. RFC Last edited by nji; 11th January 2020 at 17:11. Reason: Typo, ortho, otto |
13th January 2020, 08:55 | #42 | Link |
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I looked at LensTransform. It uses deshaker data gathered before transform and aplies them to video after transform? Is that correct?
EDIT: sorry, I missed thde point that log is bare guidance. Last edited by redfordxx; 13th January 2020 at 09:14. |
13th January 2020, 10:30 | #43 | Link |
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I'll try to explain better:
given: log data describes movement assume movement applies to image center exactly find 3d rotation for entire projection which results in given movement of the center pixel. Hope it makes sense now edit: Again, more precise way which I did not finish: given: array of motion vectors find 3d rotation which minimizes all(most) vectors
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14th January 2020, 08:33 | #44 | Link |
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I again gave try to the lens profile and handedited it until I saw any change in the frame.
I ended up with two findings: If I have perspectivemodel...no change...only fisheyemodel. If I change the profile, I have to close the the VDub for changes to take effect. Can you please confirm/explain/deny it? |
14th January 2020, 13:41 | #45 | Link |
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Yes, I wrote in first posts that only fisheye adobe profile is implemented.
Restart vdub: not really, it should reload presets every now and then. Open/close filter dialog, open/close Video->Filters dialog.
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14th January 2020, 14:24 | #46 | Link | |
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Quote:
https://forum.doom9.org/showthread.p...32#post1895232 Does this hold only for fisheye lenses? Or will it be an improvement for "normal" (rectingular) lenses too (in comparison to orig Deshaker)? EDIT Might there be an enchancement to Lens Transform so it does better for "normal" lenses? Last edited by nji; 14th January 2020 at 17:06. Reason: see EDIT |
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14th January 2020, 17:53 | #47 | Link |
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For perfect rectilinear lens all you need to know is just fov parameter, there is nothing else to describe it.
Adobe profile creator defined 2 lens models but I implemented only "fisheye" because this is the one that fits hero etc. Perspective model can be implemented too in theory, also profiles from other software can be implemented (like ptgui), or embedded gopro profiles, and so on.. as long as diagonal fov does not approach 180deg, at which point it is impossible to project it in rectilinear way. In my filter I actually don't use any formula (like polinomial) but instead I use lookup table for distortion so it is basically profile/formula independent (but applying some 'standard' profiles requires knowledge how to interpret it and test samples - this is quite some work ). Difference between Adobe "fisheye" model and "perspective" model is subtle, it is just the curvature formula which tighter fits actual lens. Same lens can be described by both models but you'll see more curvature errors in corners. "Perspective" model assumes very little radial distortion. Small distortion is more difficult to test because, well, you dont see it If you have it and want support, lets do this: post your 9 grid shots (full sensor) as required by lens creator and some exterior shots of very straight objects.
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15th January 2020, 22:35 | #48 | Link | |
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FoV, a, b, c I will defish.dll with a,b,c... Then I use lens transform with FoV value, it sould be correct? |
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16th January 2020, 11:40 | #49 | Link | |
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I dont understand how defish uses fov parameter. It cant be both the angle and control distortion... Well, with a b c the fov is not used at all. Similarly, defish does not tell you the new fov for resulting image. So you should crop or scale the result in such way that pixels at positions (0,h/2) and (w,h/2) remain in same place. Otherwise you need to calculate the new fov yourself. Link to defish for convenience https://forum.doom9.org/showthread.p...26#post1375626
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16th January 2020, 13:11 | #50 | Link | |
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Quote:
Having vaguely followed this rather meandering thread, I feel it's worth pointing out again that if the aim is to find a projection where 3D rotation can be eliminated by changing the projection, translating the image in 2D, and then changing the projection back, then no such projection exists. |
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16th January 2020, 13:41 | #51 | Link | |||
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Quote:
Quote:
So the resulting fov will be pretty much the same...or 1% change of the PTGui FoV. Quote:
I thought (w/2, h/2) should remain in the center. |
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16th January 2020, 13:42 | #52 | Link | |
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Quote:
Just for fun: what if we allow 3 passes (one for each axis)
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16th January 2020, 13:51 | #53 | Link |
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This is not what I wrote.
In this example fov is reduced (and no way to know how much).
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16th January 2020, 14:31 | #56 | Link |
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... yes, that's pretty true :-)
I can only speak for myself ... of course. And I used orig Deshaker since some time to my very satisfaction. Actually get kind of "addicted" to it ... as a calm camera is a relieve when watching. However I made the observation that if the movie has been taken by a lens with large fov then the result of orig Deshaker sometimes is worse than the shaky original movie (like on LSD etc. ) Clearly that is because Deshaker assumes/ works 2D only. So the simple question was if it would be possible to take into account the 3D origin of the movie somehow for large fovs. Your DeShaker3D obviously does it although it has some severe drawbacks (if I get it right) https://forum.doom9.org/showthread.p...58#post1895158 I thought that Lens Transform would do better. Lens Transform is also for the specific distortions of lenses, but personally I'm not about enhancing of a device I own, but about older movies where I only can tell roughly fov. And with that indoor movies (family feasts etc.) obviously taken with larger fov (but not fisheye), Lens Transform does't do good either. It does good for fisheye ... to my experience. I cannot tell what's the reason for that. Is it "by design" as to the fisheye projection? (And if ... could it be improved by offering for "normal lenses" too?) Or is it because panning and tilting (redfordxx called it rotation x and y) have more effects the larger the fov? All in all ... just a simple question from my side: How do I deshake large fov (not fisheye) movies? If not possible with up to now: Which improvements could be done ... (at Lens Transform ... as the alternatives do not do (?)) |
16th January 2020, 16:16 | #57 | Link |
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nji
"doesn't do good" is void discussion unless you demonstrate specific shots and results. In pure math adding fisheye is more complex so "flat" lens can't be worse. But the perceived quality can be ruined by many factors which are subject to research. Are you trying to find real software for the job? Have you tried Mercalli or anything else?
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16th January 2020, 16:41 | #58 | Link | ||||
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Quote:
Quote:
It is not: The more complex the better. It is: The more suitable the better, Quote:
I'm pretty sure it's simple projection math (I sadly am not able to). Research ... in the 17th century perhaps Quote:
Only software that costs LOTS of money shall be taken serious? |
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16th January 2020, 16:45 | #59 | Link | |
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Or that the "wobbling" was introduced by the compensatory stabilization method ? What kind of "wobbling?" exactly ? There are different types . Or some combination? |
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16th January 2020, 17:17 | #60 | Link | |
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Quote:
to see what this thread is about. |
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