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Demo SpiderZoom SBS:
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Le 26/11/2020 à 11:41, Etienne Monneret
(Perso) a écrit :
26/11/2020 à 11:14, Antonio F.G. via groups.io a écrit :
I have played a little with 3Denlive, and
followed the discussion on the 3D Spider-Man.
I am not fully on grips of the application but I feel it is
extremely interesting to produce videos out of a sequence of
stereo images, including zoom-in/out effects, and overlaying two
or more stereo images.
In my opinion 3Denlive as a video editor would work best if the
input SBS images are already well aligned for the main angular
parameters (visual axis rotation, h-perspective, v-perspective,
and nominal focus correction). The only alignment parameter that
makes sense for zooming in-out is the h-disparity (displacement
in the X direction).
As an example of this take one stereo image that has a 3.3%
horizontal disparity. If we make a video sequence that ends in
5x zoom-in, the disparity would become 16.5% which is obviously
too much. This is were it makes sense to displace in the X
direction trying to reduce the disparity in the zoomed-in area,
or possibly masking some area of the image that creates
As shown in this tutorial about how to use keyframes, you can
control all alignment and placement/zoom parameters to make them
adapted at each time position of the video.
You are speaking about horizontal disparity. But, on some stereos,
you may have a well-aligned whole image having some local
deformations. When zooming on these details, you may need to
completely re-align the zoomed sub-part. This is here where the
"Automatic alignment" button takes a great part of its interest!
For example, in the Spider-Man case, you may have a well-align
whole video, but it's very hard to get it properly with a
well-aligned Spider-Man (in fact, the background seems to be a
simple flat wall-paper!). You would certainly like to have a
better alignment on it when zooming.
In the tutorial, see the first screen copy point 7, and third
screen copy point 3 and 4.
Your explanations may be a bit confusing because there are two X
- the horizontal stereo shift in the Alignment configuration
- the horizontal position in the Placement configuration
In the same idea, there are two parameters that may change the
- the horizontal and vertical adaptation in the Alignment
- the zoom factor in the Placement configuration