load FacesBW

% This loads the data, H, which is (1204 x 1076) x 15.  We'll only use 4 vectors.


idx=[6 3 15 1];  % Which faces do we want to use?
H=H(:,idx);  

[Q,R]=qr(H,0);   % The columns of Q form the orthonormal basis for our face space.

m=1204; n=1076;

% NOTES:  
% To see the negative of any of the images, replace Q(:,i) by -Q(:,i)
%
% To see the original vector, replace Q(:,i) by H(:,i)
%

figure(1)
imagesc(reshape(Q(:,1),m,n));
colormap(gray); axis equal; axis off;

figure(2)
imagesc(reshape(Q(:,2),m,n));
colormap(gray); axis equal; axis off;

figure(3)
   imagesc(reshape(Q(:,3),m,n));
   colormap(gray); axis equal; axis off;

figure(4)
   imagesc(reshape(Q(:,4),m,n));
   colormap(gray); axis equal; axis off;