Finding space coordinate points for a specific object in a video

[hamid159]

Hi Everyone,
Actually, i want to make quadcopter as my final year project which will do many functions like in this video https://www.ted.com/talks/raffaello...etic_power_of_quadcopters?language=en#t-21403 .. In this video, he says there are cameras on ceiling that detect the pointer and find out its position. I think this position is actually coordinate points. How can we find out these points from video. I think it involves video processing.. But give me idea how it is working??

 

[BradtheRad]

The simple way is to install an led on the craft. The led should be a unique color, different from every object in the field of view.

Your camera shoots frames of video, which it sends to your computer.

Have your algorithm examine each frame, looking for that specific color. This will give you the craft's location in the frame.

If you need to know the craft's orientation, install two led's. Each should be a unique color.

 

[hamid159]

Thanks BradtheRad for you suggestion...
but how is it going to give me the location by using just 1 LED. As the frame will be 2 dimensional.. but the space is 3 dimensional.. Computer will detect that color of LED in 2D and give me just 2D point. isn't it?

 

[BradtheRad]

Theoretically you could locate in 3 dimensions by installing 3 led's on the craft. It would create a triangle which will display as a unique shape, for every position and height. However it will not be easy to accurately gauge its perspective. Therefore I think 4 led's would be more useful.

Have you seen tv programs where the narrator seems to hold a virtual object in his hand? The object is created by computer graphics imaging. A band is wrapped around his hand, to which is attached 7 or 8 colored led's.

I suppose the computer reads the 2D camera video, detects the positions of the led's, and calculates a precise 3D position for the narrator's hand.