function m = makeMap
%===================================================================
%  function m = makeMap
%
%  Returns a binary map m, where m(i,j)==0 when (i,j)
%  corresponds to a wall pixel, and 255 otherwise.
%===================================================================

m = 255*ones(300,400);
m(21:280,21:25)=0;
m(21:280,375:380)=0;
m(21:25,21:375)=0;
m(275:280,21:375)=0;
m(100:105,21:380)=0;
m(191:195,21:380)=0;
m(191:195,61:110)=255;
m(191:195,161:240)=255;
m(191:280,156:160)=0;
m(191:280,241:245)=0;
m(216:255,241:245)=255;
m(100:105,176:225)=255;
m(100:105,281:321)=255;
m(21:45,21:60)=0;
m(21:105,251:255)=0;
m(51:75,251:255)=255;

close all;
imagesc(m);
colormap gray;