How would one segment large area's of gray (ranging from white to black) from an image ? (If you know this in opencv, you may answer by saying what you would do in opencv). For example given this picture:
You see that this is a large area of gray and it is clearly distinguishable from the rest. How can you segment this if this area can have any shade of gray and it has to work in real-time.
Thx in advance.