Uploaded on 2016-07-31 by Flora Bugan

This picture isn't mine (original source is Wikipedia), I couldn't take one. You can see where the main public transportation is based - there're two city trains in downtown Debrecen. Using Chen Zhong's first example, I would like to introduce you an invisible information that is extracted from the picture's visible data. Analyzing people's traveling habits, we can have a better transportation system.