Word got out that I know programming in python and someone came to ask me about image processing - counting cars passing in a higway using algorithm. :-o .
since I am an electrical engineer pretending to know everything else, I did try to help, though I repeatedly mentioned that I would be of little help and the best I could do is to offer bits and pieces of info.

But then it was an interesting experience as now I got to know a bit about how image processing is done. The person had looked up some code in the internet. It involved using openCV library and then feeding an xml file called 'cars.xml' to it to the function in openCV. The challenge lies in finding/generating the cars.xml files that detects cars properly. This person's program was awry, was not only detecting cars, but randomly tagging road as car. I assume that it uses some sort of colour threshold to detect.