two pass split window filter

i have spectrogram time X frequency matrix ,with peaks that i want, and noise that i dont want, so, how to use two pass split window filter on the signal to make it more clean.

Answer 1

[Mohammad Khishe]

you can use following commands:

%# some random data resembling yours

x = randn(100,1);

x(75) = -14; x(25) = 20;

subplot(211), plot(x)

%# zero out everything but the high peaks

mu = mean(x); sd = std(x); Z = 3;

x( abs(x-mu) < Z*sd ) = 0;

subplot(212), plot(x)