J, 15 chars
(-:>./"1<./>./)
Didn't expect this short solution.
Short explanation:
(input == ((max of rows of input) table with min of left and right (max in columns of input)))
( -: >./"1 <./ >./ )
If your function is 4 other function like in the solution: (f1 f2 f3 f4)
and an input J computes it like f1(input,f3(f2(input),f4(input)))
i.e. input f1 ((f2 input) f3 (f4 input))
.