[ale] OT: Video Motion Sensor

[Jeff Hubbs]

Geoffrey wrote:

>Makes you realize how advanced the human brain 
>and eye coordination really is.
>
Especially when you consider how few different parts are involved and 
how they can be manufactured in high quantities by unskilled labor. :)

>A single camera is only going to deal 
>with, for the most part, 2 dimensions.  It's a lot easier to detect a 
>vehicle traveling perpendicular to your direction, but consider one 
>coming straight at you.  They change in the image is substantially less 
>apparent.  Add another camera at a fair distance away from the other, 
>and you've got better data to make the decisions, but very complicated 
>calculations.
>  
>
One possible approach would be to detect left-right-symmetrical objects 
(nearly all road vehicles would have this symmetry), establish bounding 
rectangles around them, and then secondarily look for rectangles that 
are growing.  The rate of the growth is and the overall movement of the 
rectangle could be used to form a prediction cone in space and time.  I 
don't know if you'd be able to compensate for the difference between a 
Toyota Echo and a '61 Caddy, but maybe you could; sounds like a real 
teeth-grinder.