Daniel@0: function d = histCmpChi2(h1, h2)
Daniel@0: % Compare two histograms using chi-squared
Daniel@0: % function d = histCmpChi2(h1, h2)
Daniel@0: %
Daniel@0: % d(i,j) = chi^2(h1(i,:), h2(j,:)) = sum_b  (h1(i,b)-h2(j,b)^2 / (h1(i,b) + h2(j,b))
Daniel@0: 
Daniel@0: [N B] = size(h1);
Daniel@0: d = zeros(N,N);
Daniel@0: for i=1:N
Daniel@0:   h1i = repmat(h1(i,:), N, 1);
Daniel@0:   numer = (h1i - h2).^2;
Daniel@0:   denom = h1i + h2 + eps; % if denom=0, then numer=0
Daniel@0:   d(i,:) = sum(numer ./ denom, 2);
Daniel@0: end
Daniel@0: