[hackerspaces] Laser "touch" screen?

[Lokkju Brennr]

It's relatively easy to do, and in fact has even been done on a *huge*
scale.  Check out the L.A.S.E.R. Tag project from Graffiti Research
Labs, for instance - 6000 lumen projector, webcam with an extra lens
or two, and the entire side of a building.
Probably the best starting point currently is either Myron
(http://webcamxtra.sourceforge.net/) or else OpenCV.

Loki

On Sat, Dec 17, 2011 at 12:51 PM, B F <bakmthiscl at gmail.com> wrote:
> It occurred to me that we have touch screens and we have laser
> pointers, but can we combine the two concepts and have a laser pointer
> that works on a projected image from a freehand-held pointer?  I.e.,
> you could easily implement what appears to be this if working at the
> computer screen, but can it be done (easily) while standing at the
> lectern beside the projector screen?
>
> I figure someone has probably invented this.  But if not, then a
> simple camera specifically sensitive to the reflected red (or red+IR)
> dot could be
> coordinated with a few projected marks on the screen to initialize
> the system.  After that the camera would simply see where the pointer
> was and would respond, perhaps, to a coded strobe signal from the
> pointer to actuate
> whatever feature (URL link or whatever) was projected at that spot.
>
> Any feedback?
>
> Bruce Freeman
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