function [z,mu,sigma] = gen_pat(n,m)

delta = 20;
sigma = 32;

[x,y] = meshgrid(1:n,1:m);

z = sqrt((x-round(n/2)).^2+(y-round(m/2)).^2)<round((n+m)/8);
z = z+1;

mu(1) = 127 - delta/2;
mu(2) = 127 + delta/2;

sigma(1) = sigma;
sigma(2) = sigma;

