Robot NXT brick collector

This robot collects the bricks in the green field autonomously.
It recognizes the red bricks with the help of a webcam and it commands the arm to pick them up.
It works well in any condition of light thanks to a transformation of the color space.
Once all the bricks have been collected, they are thrown back into the field. The process starts then again.
The cycle can go on for ever
The robot is built all with original LEGO pieces, except the webcam.
It is built with 2 LEGO Mindstorms NXT units, 4 nxt motors, 2 touch sensors.