im = imread('PPLAG RUN3 FBELT5 L.jpg');
%f = load('mandrill');  im = ind2gray(f.X,f.map);
img = double(im(:,:,1));

figure; imagesc(img);  colormap(gray);  title('orig');

% Downsample by 5
figure; imagesc(img(1:5:end,1:5:end));  colormap(gray);  title('d5');
img5 = conv2(img,ones(5,5)/25,'same');
figure; imagesc(img5(1:5:end,1:5:end));  colormap(gray);  title('d5s');

% Downsample by 10
figure; imagesc(img(1:10:end,1:10:end));  colormap(gray);  title('d10');
img10 = conv2(img,ones(10,10)/100,'same');
figure; imagesc(img10(1:10:end,1:10:end));  colormap(gray);  title('d10s');
