coordinates
r = [ 1 0 0; 1 1 0; 1 0 0.5]; g = [ 0 1 0; 1 1 0; 0 1 0.5]; b = [0 0 1; 0 1 0; 1 1 0.5]; im = cat(3,r,g,b); scl = 81; ims = imresize(im,scl,'nearest'); close all imshow(ims);
imshow(ims); xoff = linspace(-0.5,0.5,5); x = 1+xoff; y = 2+zeros(size(xoff)); hold on plot((x-0.5)*scl+0.5,(y-0.5)*scl+0.5,'kx'); hold off
imb = ones(256,256,3); imb(101:103,101:103,:) = im; imshow(imb); xoff = linspace(-0.5,0.5,5); x = 101+xoff; y = 102+zeros(size(xoff)); hold on plot(x,y,'kx'); hold off % use magnifying tool to zoom into pixel image