function [edges] = nonMaxSupress(G, labels)
  G = padarray(G, [1, 1], 'both');
  labels = padarray(labels, [1, 1], 'both');
  [R, C] = size(G);
  edges = zeros(size(G));
  for i = 2:R - 1
    for j = 2:C - 1
      label = labels(i, j);
      if (label == 0 && G(i, j) > G(i, j - 1) && G(i, j) > G(i, j + 1))
        edges(i, j) = G(i, j);
      endif

      if (label == 1 && G(i, j) > G(i + 1, j - 1) && G(i, j) > G(i - 1, j + 1))
        edges(i, j) = G(i, j);
      endif

      if (label == 2 && G(i, j) > G(i + 1, j) && G(i, j) > G(i - 1, j))
        edges(i, j) = G(i, j);
      endif

      if (label == 3 && G(i, j) > G(i - 1, j - 1) && G(i, j) > G(i + 1, j + 1))
        edges(i, j) = G(i, j);
      endif
    endfor
  endfor
endfunction