The range of topics considered in graph drawing includes graph algorithms, graph theory, geometry, topology, visual languages, visual perception, information visualization, computer-human interaction, and graphic design.
The Contrast Sensitivity Function
Prepared by Peter Wenderoth
Imagine that you are driving a car in a very thick fog. Objects which are normally easily seen, like black writing on a white billboard, will be hard to see because the black writing and the white background will both be greyish. That is the difference between whites and blacks - contrast - will be reduced