Panorama activity

[Eben Eliason]

Ben -
That's a lot of shots.  Can you do some tests to determine the minimal
required number that still produces decent stitches?  Would 25% overlap be
sufficient?  We could try to indicate the angle for the next photo with
icons, but I feel like 8 shots or so is the maximum we could require before
the icons looked nearly the same in any 3 adjacent positions.

Here's another thought....I know this is probably pushing things a lot on
our little machine, but how long would a single diff take to determine the
angle between a previously taken photo and a newly taken one.  I envision
snapping the first photo 'A' in the sequence, and then having onscreen
instructions tell the kid to 'swivel to the right'.  Then, if you could grab
a still every second in the background while she swivels, lets say, and
determine its overlap with the previous photo A, we could switch the
onscreen controls to indicate 'stop here and take photo B' and so on, with
live feedback.  If they move too fast and you can't find any overlap, we can
switch and say 'swivel back to the left.'

Depending on the speed you can do this at, we could even have a little
horizontal "meter" with a ball in it, and they just have to get the ball to
the center, like a level, to line up the next shot.  It wouldn't be smooth,
but at least it would be obvious.

What do you think?

- Eben



On 6/20/07, Benjamin M. Schwartz <bmschwar at fas.harvard.edu> wrote:
>
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> Samuel Klein wrote:
> > do we have a way of telling or
> > estimating the XO's swivel angle from hardware?
>
> The stitcher determines the angle from the images themselves.
> I'm not aware of any helpful hardware.
>
> Eben Eliason wrote:
> > Ben, what's the viewing
> > angle of the camera?  Is 6 shots sufficient?
>
> The horizontal viewing angle is about 45 degrees.  That means that 16
> shots are
> required if successive frames overlap by 50%.  I took 16 frames using the
> Capture activity in a minute or two.  Good interface design will be
> required to
> make this process painless.  Obviously, panoramas less than 360 degrees
> require
> fewer shots.
>
> - --Ben
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