how to code simple motion tracking?

I am making a sentry turret with servos and a paintball gun and need to implement real time motion tracing to make the gun shoot anything that moves. how can I code this(any good algorithms, boo开发者_运维问答ks, tutorials)? I want to make it myself and not use premade solutions.

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Lucas-Kanade with Kalman filtering is the bread and butter motion tracking algorithm. However, it's a bit outdated.

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We (Success Labs) just published a Lucas-Kanade app for the iPhone. You can read about it here - http://www.success-ware.com/150842/Lucas-Kanade-Detection-for-the-iPhone

There's a link to the AppStore, and source code as well.

HTH, Oded.