Method blur

dep/agg/include/agg_blur.h:676–681

        //--------------------------------------------------------------------
        template <class Img>
        void blur(Img& img, unsigned radius)
        {
            blur_x(img, radius);
            pixfmt_transposer<Img> img2(img);
            blur_x(img2, radius);
        }

    private:
        pod_vector<color_type> m_buf;