std::vector<unsigned> hei_line(COLS);
    std::vector<unsigned> hei_prev(COLS);
    std::vector<unsigned> col_y(COLS);

    for(unsigned l=0; l<LINES; ++l) {
        // calcul de h_l
        for(unsigned c=0; c<COLS; ++c) {
            if(im({c,l}) == od::Color::White) {
                hei_line[c] = 0;
            } else {
                if(l > 0) {
                    hei_line[c] = hei_prev[c]+1;
                }
                else {
                    hei_line[c] = 1;
                }
            }
        }
        hei_prev = hei_line;
        // Enumération de tous les bords gauche et droit
        for(unsigned c1=0; c1<COLS; ++c1) {
            unsigned h = 0xFFFFFFFF;
            for(unsigned c2=c1; c2<COLS; ++c2) {
                h = std::min(h, hei_line[c2]);

                unsigned wid = c2 - c1 + 1;
                unsigned hei = h;
                unsigned area = wid * hei;

                if(max.area < area) {
                    max.pos.x = c1;
                    max.pos.y = l - hei + 1;
                    max.size.wid = wid;
                    max.size.hei = hei;
                    max.area = area;
                }
            }
        }
    }