Vision is a process that produces from images of the external world a description that is useful to the viewer and not cluttered with irrelevant info… - David Marr

Vision is the process of discovering from images what is present in the world, and where it is.

Vision is the process of discovering from images what is present in the world, and where it is.

The critical act in formulating computational theories turns out to be the discovery of valid constraints on the way the world is structured -- constraints that provide sufficient information to allow the processing to succeed.

[If] we can experimentally isolate a process and show that it can still work well, then it cannot require complex interaction with other parts of vision and can therefore be understood relatively well on its own.