                                 const uchar* lle = cleft + yi * cimg_step + xi * channels;
                                 const uchar* lri = cright + yi * cimg_step + xr * channels;
 
-                                val += DataCostPerPixel<channels>::compute(lle, lri);
+                                val += pixeldiff<channels>(lle, lri);
                             }
                         }
                     }


                        for(int y = 0; y < len; ++y)
                        {
                            val += DataCostPerPixel<channels>::compute(lle, lri);

                            lle += cimg_step;
                            lri += cimg_step;

        /////////////////////// init data cost ////////////////////////
        ///////////////////////////////////////////////////////////////

        template <int channels> float __device__ pixeldiff(const uchar* left, const uchar* right);
        template<> float __device__ __forceinline__ pixeldiff<1>(const uchar* left, const uchar* right)
        {
            return cdata_weight * fmin( ::abs((int)*left - *right), cmax_data_term);
        }
        template <> float __device__ __forceinline__ pixeldiff<3>(const uchar* left, const uchar* right)
        {
            float tb = 0.114f * ::abs((int)left[0] - right[0]);
            float tg = 0.587f * ::abs((int)left[1] - right[1]);
            float tr = 0.299f * ::abs((int)left[2] - right[2]);

            return cdata_weight * fmin(tr + tg + tb, cmax_data_term);
        }
        template <> float __device__ __forceinline__ pixeldiff<4>(const uchar* left, const uchar* right)
        {
            uchar4 l = *((const uchar4*)left);
            uchar4 r = *((const uchar4*)right);

            float tb = 0.114f * ::abs((int)l.x - r.x);
            float tg = 0.587f * ::abs((int)l.y - r.y);
            float tr = 0.299f * ::abs((int)l.z - r.z);

            return cdata_weight * fmin(tr + tg + tb, cmax_data_term);
        }

        template <typename T>
        __global__ void get_first_k_initial_global(uchar *ctemp, T* data_cost_selected_, T *selected_disp_pyr, int h, int w, int nr_plane, int ndisp)
