function rgb = bipolar_image(im,style)
%

if nargin<2
    style = 2;
end

switch (style)
    case {0}
        rgb = (im+1)/2;
    case {1}
        r = zeros(size(im));
        g = r;
        b = r;
        idx = find(im>0);
        r(idx) = im(idx);
        idx = find(im<0);
        b(idx) = -im(idx);
        rgb = cat(3,r,g,b);
    otherwise
        r = ones(size(im));
        g = r;
        b = r;
        idx = find(im>0);
        g(idx) = 1 - im(idx);
        b(idx) = g(idx);
        idx = find(im<0);
        g(idx) = 1 + im(idx);
        r(idx) = g(idx);
        rgb = cat(3,r,g,b);
end
if nargout<1
    imshow(rgb);
end