function [mc_val] = cal_mutual_coherence(dic_mat, plot_flag)

[~, N] = size(dic_mat);

for idx = 1 : N
    for jdx = 1 : N
        if idx ~= jdx
            mc(idx, jdx) = abs(dic_mat(:, idx)' * dic_mat(:, jdx)) / norm(dic_mat(:, idx))^2;
        else
            mc(idx, jdx) = 0;
        end
    end
end

if plot_flag == 1
    figure
    imagesc(mc)
end

mc_val = max(max(mc));


end