 = r_sum = g_sum = b_sum = <span class="number">0</span>

        r_out_sum = radiusPlus1 * (pr = pixels[yi])
        g_out_sum = radiusPlus1 * (pg = pixels[yi + <span class="number">1</span>])
        b_out_sum = radiusPlus1 * (pb = pixels[yi + <span class="number">2</span>])

        r_sum += sumFactor * pr
        g_sum += sumFactor * pg
        b_sum += sumFactor * pb

        stack = stackStart
        
        <span class="keyword">for</span> i <span class="keyword">in</span> [<span class="number">0.<