Hi Dragan,

Thanks again for another excellent reply.

I have successfully implemented a C# program using this algorithm. The program uses 3 test photos. The first image contains a single obstacle which is positioned centrally at a distance of 30cms. The second is positioned at 60cms and the third at 90cms. I had to play around with the camera angle and found that 45 degrees gives me near 100% accuracy which I suppose is correct as I am currently using a 3G phone?

Do you know how to approximate the angle of the obstacle from the camera? This data would enable me to create a 2D (birds-eye-view) local map for the robot. I am guessing that the algorithm would require some existing arguments and perhaps the coordinates of the obstacle's centre point? (I can work out these coordinates)

Your continued assistance is greatly appreciated.

Best