%the 'other' gradient
function out = o_grad(img)
    img = rgb2gray(img);
    img = medfilt2(img,[7,7]);
    out = gradient(img);
%    out = mat2gray(out);
    
    
    thres = prctile(out(:), 99.78);
    %out = dialate(out, thres);
    
    se = strel('disk',30);
    out = imdilate(out, se);
    
    out = out .* (out >= thres);