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Old 16th January 2020, 22:33   #61  |  Link
poisondeathray
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Quote:
Originally Posted by nji View Post
Try to deshake a global shutter large fov movie...
to see what this thread is about.

This thread is about lens correction.

After you "undo" the lens distortion - how is this any different than other scenarios?

I'm simply asking you to clarify what you mean by "wobbling"
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Old 16th January 2020, 23:45   #62  |  Link
nji
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Yes, you are right, the thread is about lens correction (tool).

And we're discussing how to make it useable not only
for well known lenses but also if only known of a large fov.
For in that case all deshaker do bad.

It's difficult for me to describe what the effect looks like
that I called "wobbling".
Actually "wobbling" seems not to be the right English word for it.
(I don't know a fitting word).
It's more like "kneads".
And it seems to be caused when tilting and panning
a large fov movie.
Why don't you have a look for yourself as I suggested?

Last edited by nji; 16th January 2020 at 23:48.
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Old 17th January 2020, 00:24   #63  |  Link
redfordxx
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Concerning wobbling...

If the wobbling is panning and tilting the camera... or as I said rotation around x and y axis...

Can someone stronger than me in math help me?

When I rotate camera precisely around x axis...
...does quad help me with symetric transform (zoom bottom or top of the image) to compensate completely...or there is some curve involved?
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Old 17th January 2020, 00:32   #64  |  Link
redfordxx
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Quote:
Originally Posted by shekh View Post
In this example fov is reduced (and no way to know how much).
I guess PTGui would tell you... there is final FoV of your panorama ... and your panorama can be only one image.
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Old 17th January 2020, 03:19   #65  |  Link
poisondeathray
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Quote:
Originally Posted by nji View Post
Yes, you are right, the thread is about lens correction (tool).

And we're discussing how to make it useable not only
for well known lenses but also if only known of a large fov.
For in that case all deshaker do bad.

It's difficult for me to describe what the effect looks like
that I called "wobbling".
Actually "wobbling" seems not to be the right English word for it.
(I don't know a fitting word).
It's more like "kneads".
And it seems to be caused when tilting and panning
a large fov movie.
Why don't you have a look for yourself as I suggested?

I would, but I don't have any of those types of cameras anymore. I'm trying to think back - maybe DV, wide angle lens. Maybe you have something different, because I don't remember having any "wobbling" problem with those. But like you say maybe that was the wrong wording or description.

It doesn't make logical sense that you say it "works" with something more extreme like fisheye, but not something less extreme like a wide angle lens. If what you're describing is related to the lens distortion, shouldn't a more extreme distortion cause more problems ?


How do you expect shekh or any developer to improve any of these tools , or make them "more useable" - without any footage, settings, or at the very least an accurate description?

A video is worth a thousand words. Find some footage without people or personally identifiable elements. Or find footage from same or similar camera / lens somewhere else that demonstrates the issue clearly

When I want something fixed or improved, I go out of my way to provide footage, description, upload everything in a neat package. I want the developer to do as less work as possible, so that he or she would be more inclined to help, instead of having to do the "legwork" themselves.
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Old 18th January 2020, 10:37   #66  |  Link
nji
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Quote:
Originally Posted by redfordxx View Post
If the wobbling is panning and tilting the camera... or as I said rotation around x and y axis...
Slowly please!
That's my concretization of the effect I am adressing here.
(I'm no native speaker so my words my not always hit.
And "wobbling" maybe was even wrong, as "wobbling" seems to be the same than "shaking".
I tried to find a better fitting word, it that was (see above) "kneads within".)
This effect occurs - to my observation - allways if you 2D deshake a large fov movie. (I wonder how often I wrote this expression in this thread)

Quote:
Originally Posted by redfordxx View Post
Can someone stronger than me in math help me?
To say it explicitly: That won't be me.
As I don't know enough either.
And the answers (kindly by shekh and wonkey_monkey) gave me ever more questions.

Quote:
Originally Posted by redfordxx View Post
When I rotate camera precisely around x axis...
...does quad help me with symetric transform (zoom bottom or top of the image) to compensate completely...or there is some curve involved?
quad is Avisynth I don't know anything about (& different sub forum).
But if it does simply resize lines wrt to a reference line, then it will be correct only for fov = 0.
(No math, but just simple imagination )

Sorry, but I'm at a loss like you. Can't help any better.
Tried to contribute by describing an effect that possibly could be enhanced.
Ran against walls.
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Old 18th January 2020, 12:57   #67  |  Link
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A transformation with quad is equivalent to the 3D rotation which would put the corners in the same positions (for a rectilinear view, anyway).
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Old 24th January 2020, 15:18   #68  |  Link
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Quote:
Originally Posted by wonkey_monkey View Post
A transformation with quad is equivalent to the 3D rotation which would put the corners in the same positions (for a rectilinear view, anyway).
Thank you.

Can you help me please one more?

When I want to simulate rotation around x and y...not z axis.

I have
d ...direction of combined rotation (0..360) degrees
a ...amount of rotation > 0 degrees
w,h ...dimension of video.

How will I calculate the 4 points for quad?
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Old 25th January 2020, 02:32   #69  |  Link
poisondeathray
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Quote:
Originally Posted by redfordxx View Post

When I want to simulate rotation around x and y...not z axis.

I have
d ...direction of combined rotation (0..360) degrees
a ...amount of rotation > 0 degrees
w,h ...dimension of video.

How will I calculate the 4 points for quad?
maybe this old post will help or get you started ? the math is there with cosine , sine
https://forum.doom9.org/showthread.php?t=167797

the avisynth part was taken from that post (but the older version, not the revised version)
https://stackoverflow.com/questions/...und-its-x-axis
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Old 25th January 2020, 13:02   #70  |  Link
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Quote:
Originally Posted by poisondeathray View Post
maybe this old post will help or get you started ? the math is there with cosine , sine
https://forum.doom9.org/showthread.php?t=167797

the avisynth part was taken from that post (but the older version, not the revised version)
https://stackoverflow.com/questions/...und-its-x-axis
This seem to be rotation around the objects axis.
I need rotation around camera axis.
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Old 25th January 2020, 17:04   #71  |  Link
poisondeathray
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Originally Posted by redfordxx View Post
This seem to be rotation around the objects axis.
I need rotation around camera axis.
Maybe you can make some rough assumptions like focal length, etc... just to make the representation work ?


Camera rotation is really pan (camera y-axis rot) and tilt (camera x-axis rotation) .

It will also depend on the camera and lens characteristics, focal length, sensor size to determine the camera rotation axis of your particular shot. In short, you need to do a 3d camera solve to determine the relationship of the camera to the scene contents.

A single set of variables like r,a,w,h won't be able to manipulate this for all types of cameras setups, lens and shots ; or it won't give you similar results across different cameras.

You have a single 2D "plane" representation with all objects, far and close on that 2D plane. You're going to get problem with parallax and perspective in many types of shots and camera movements

The proper way to do it is 3d camera mapping. You track the shot with a 3d tracker and create a virtual projection camera. You can project your video onto geometry and use a 2nd camera to adjust the camera move. There are free ways to do this in blender (not as good as commercial methods) . And there are old free 3d trackers like voodoo. The benefit of voodoo is it fires a bunch of trackpoints like hundreds (in native blender you have to set the point locations manually), but it's quite a dated program and 32bit.

You might be able to look at the export data and coordinates an "massage" it to plug into deshaker, deshaker3d or quad (it can export blender scripts and plain text files) . It gives camera position (x,y,z) , axis (3 coordinate , 3 axis = 9 values) , focal length, field of view data
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Old 26th January 2020, 11:16   #72  |  Link
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OK, I see it is much more complex than I thought.

Now, I spent few hour on rotation clip, but it is notworking as it is supposed to, I think.
I post it probably later somewhere, so maybe someone finds the problem.
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Old 26th January 2020, 16:17   #73  |  Link
poisondeathray
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Originally Posted by redfordxx View Post
OK, I see it is much more complex than I thought.

Now, I spent few hour on rotation clip, but it is notworking as it is supposed to, I think.
I post it probably later somewhere, so maybe someone finds the problem.
You would have to make some assumptions about camera distance to a "target" plane ; the effect of camera rotation on the "2.5d" plane would look quite different depending on different distances for a given camera/lens setup. Up close , the sheer effect on the 2.5d plane would be greater (greater angles for a given degree of rotation). A far shot would have less effect, the end result approaches something closer to translation x,y

But you're not necessarily looking for mathematically correct optics, are you ? You're only looking for a closer "match" as determined by deshaker %ok blocks . ie. It's not necessary that your "label" of "x,y" degree rotation is accurate, only that it "looks" more similar to the previous frame
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Old 26th January 2020, 16:54   #74  |  Link
redfordxx
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As I presented i the warp thread, I calculated focal distance from FoV which I know.

I don't know what is "2.5d"...
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Old 26th January 2020, 22:28   #75  |  Link
poisondeathray
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Originally Posted by redfordxx View Post
I don't know what is "2.5d"...

"2.5D" is the term used to describe "flat" 2D planes in 3D space. It's not "2D" , but not quite "3D" either... hence the name "2.5D"
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