how can I plot cross-correlate two 2-D functions

 How can integrate and plot |X(tau,f)|
 Where X(tau,f)= Int {s(t).s(t-tau).exp(j*2*pi*f*t)} dt

 for s(t)=rect(t/T)

 -2T<tau<2T
-2.5/T<f<2.5/T