As part of my final year design project, I designed a mobile robot that was capable of detecting obstacles using an on board webcam. The following code was running on a Raspberry Pi platform and was processing the incoming images in real-time. In order to make my code simple to use due to time constraint, I used blob detection which will allow the code to search for a black blob. Once a black blob was detected, the algorithm then make sure that the blobs forms a circle. In case of a circle, the algorithm then measures the size of the circle to determine the distance of the circular blob from the mobile robot. The setup of the mobile robot can be found in my blog: http://chocolateamplifier.tumblr.com/post/113655961020/a-mobile-robot-with-vision-based-obstacle