Hack-a-Day article: Quantifying Cloudiness with OpenCV (Home built sensor)

Here is an article from Hack-a-Day about a project that quantifies visibility by examining an image of a distant tall building. From my office hear in Phoenix you can see a mountain in the distance almost at the horizon. The contrast between the mountain and the sky varies considerably depending on the visibility, at least during the day, and I have been thinking about fixing up some kind of sensor to measure the contrast, assuming I can find my roundtuit.

http://hackaday.com/2013/02/07/quantifying-cloudiness-with-opencv/

Steve