diff --git a/modules/core/src/sum.simd.hpp b/modules/core/src/sum.simd.hpp
new file mode 100644
index 0000000000..30cee85b4c
--- /dev/null
+++ b/modules/core/src/sum.simd.hpp
@@ -0,0 +1,662 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html
+
+
+#include "precomp.hpp"
+#include "opencl_kernels_core.hpp"
+#include "stat.hpp"
+
+namespace cv
+{
+
+template <typename T, typename ST>
+struct Sum_SIMD
+{
+    int operator () (const T *, const uchar *, ST *, int, int) const
+    {
+        return 0;
+    }
+};
+
+#if CV_SIMD
+
+template <>
+struct Sum_SIMD<uchar, int>
+{
+    int operator () (const uchar * src0, const uchar * mask, int * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_uint32 v_sum = vx_setzero_u32();
+
+        int len0 = len & -v_uint8::nlanes;
+        while (x < len0)
+        {
+            const int len_tmp = min(x + 256*v_uint16::nlanes, len0);
+            v_uint16 v_sum16 = vx_setzero_u16();
+            for (; x < len_tmp; x += v_uint8::nlanes)
+            {
+                v_uint16 v_src0, v_src1;
+                v_expand(vx_load(src0 + x), v_src0, v_src1);
+                v_sum16 += v_src0 + v_src1;
+            }
+            v_uint32 v_half0, v_half1;
+            v_expand(v_sum16, v_half0, v_half1);
+            v_sum += v_half0 + v_half1;
+        }
+        if (x <= len - v_uint16::nlanes)
+        {
+            v_uint32 v_half0, v_half1;
+            v_expand(vx_load_expand(src0 + x), v_half0, v_half1);
+            v_sum += v_half0 + v_half1;
+            x += v_uint16::nlanes;
+        }
+        if (x <= len - v_uint32::nlanes)
+        {
+            v_sum += vx_load_expand_q(src0 + x);
+            x += v_uint32::nlanes;
+        }
+
+        if (cn == 1)
+            *dst += v_reduce_sum(v_sum);
+        else
+        {
+            uint32_t CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_uint32::nlanes];
+            v_store_aligned(ar, v_sum);
+            for (int i = 0; i < v_uint32::nlanes; ++i)
+                dst[i % cn] += ar[i];
+        }
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+
+template <>
+struct Sum_SIMD<schar, int>
+{
+    int operator () (const schar * src0, const uchar * mask, int * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_int32 v_sum = vx_setzero_s32();
+
+        int len0 = len & -v_int8::nlanes;
+        while (x < len0)
+        {
+            const int len_tmp = min(x + 256*v_int16::nlanes, len0);
+            v_int16 v_sum16 = vx_setzero_s16();
+            for (; x < len_tmp; x += v_int8::nlanes)
+            {
+                v_int16 v_src0, v_src1;
+                v_expand(vx_load(src0 + x), v_src0, v_src1);
+                v_sum16 += v_src0 + v_src1;
+            }
+            v_int32 v_half0, v_half1;
+            v_expand(v_sum16, v_half0, v_half1);
+            v_sum += v_half0 + v_half1;
+        }
+        if (x <= len - v_int16::nlanes)
+        {
+            v_int32 v_half0, v_half1;
+            v_expand(vx_load_expand(src0 + x), v_half0, v_half1);
+            v_sum += v_half0 + v_half1;
+            x += v_int16::nlanes;
+        }
+        if (x <= len - v_int32::nlanes)
+        {
+            v_sum += vx_load_expand_q(src0 + x);
+            x += v_int32::nlanes;
+        }
+
+        if (cn == 1)
+            *dst += v_reduce_sum(v_sum);
+        else
+        {
+            int32_t CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_int32::nlanes];
+            v_store_aligned(ar, v_sum);
+            for (int i = 0; i < v_int32::nlanes; ++i)
+                dst[i % cn] += ar[i];
+        }
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+
+template <>
+struct Sum_SIMD<ushort, int>
+{
+    int operator () (const ushort * src0, const uchar * mask, int * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_uint32 v_sum = vx_setzero_u32();
+
+        for (; x <= len - v_uint16::nlanes; x += v_uint16::nlanes)
+        {
+            v_uint32 v_src0, v_src1;
+            v_expand(vx_load(src0 + x), v_src0, v_src1);
+            v_sum += v_src0 + v_src1;
+        }
+        if (x <= len - v_uint32::nlanes)
+        {
+            v_sum += vx_load_expand(src0 + x);
+            x += v_uint32::nlanes;
+        }
+
+        if (cn == 1)
+            *dst += v_reduce_sum(v_sum);
+        else
+        {
+            uint32_t CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_uint32::nlanes];
+            v_store_aligned(ar, v_sum);
+            for (int i = 0; i < v_uint32::nlanes; ++i)
+                dst[i % cn] += ar[i];
+        }
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+
+template <>
+struct Sum_SIMD<short, int>
+{
+    int operator () (const short * src0, const uchar * mask, int * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_int32 v_sum = vx_setzero_s32();
+
+        for (; x <= len - v_int16::nlanes; x += v_int16::nlanes)
+        {
+            v_int32 v_src0, v_src1;
+            v_expand(vx_load(src0 + x), v_src0, v_src1);
+            v_sum += v_src0 + v_src1;
+        }
+        if (x <= len - v_int32::nlanes)
+        {
+            v_sum += vx_load_expand(src0 + x);
+            x += v_int32::nlanes;
+        }
+
+        if (cn == 1)
+            *dst += v_reduce_sum(v_sum);
+        else
+        {
+            int32_t CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_int32::nlanes];
+            v_store_aligned(ar, v_sum);
+            for (int i = 0; i < v_int32::nlanes; ++i)
+                dst[i % cn] += ar[i];
+        }
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+
+#if CV_SIMD_64F
+template <>
+struct Sum_SIMD<int, double>
+{
+    int operator () (const int * src0, const uchar * mask, double * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_float64 v_sum0 = vx_setzero_f64();
+        v_float64 v_sum1 = vx_setzero_f64();
+
+        for (; x <= len - 2 * v_int32::nlanes; x += 2 * v_int32::nlanes)
+        {
+            v_int32 v_src0 = vx_load(src0 + x);
+            v_int32 v_src1 = vx_load(src0 + x + v_int32::nlanes);
+            v_sum0 += v_cvt_f64(v_src0) + v_cvt_f64(v_src1);
+            v_sum1 += v_cvt_f64_high(v_src0) + v_cvt_f64_high(v_src1);
+        }
+
+#if CV_SIMD256 || CV_SIMD512
+        double CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_float64::nlanes];
+        v_store_aligned(ar, v_sum0 + v_sum1);
+        for (int i = 0; i < v_float64::nlanes; ++i)
+            dst[i % cn] += ar[i];
+#else
+        double CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[2 * v_float64::nlanes];
+        v_store_aligned(ar, v_sum0);
+        v_store_aligned(ar + v_float64::nlanes, v_sum1);
+        for (int i = 0; i < 2 * v_float64::nlanes; ++i)
+            dst[i % cn] += ar[i];
+#endif
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+
+template <>
+struct Sum_SIMD<float, double>
+{
+    int operator () (const float * src0, const uchar * mask, double * dst, int len, int cn) const
+    {
+        if (mask || (cn != 1 && cn != 2 && cn != 4))
+            return 0;
+        len *= cn;
+
+        int x = 0;
+        v_float64 v_sum0 = vx_setzero_f64();
+        v_float64 v_sum1 = vx_setzero_f64();
+
+        for (; x <= len - 2 * v_float32::nlanes; x += 2 * v_float32::nlanes)
+        {
+            v_float32 v_src0 = vx_load(src0 + x);
+            v_float32 v_src1 = vx_load(src0 + x + v_float32::nlanes);
+            v_sum0 += v_cvt_f64(v_src0) + v_cvt_f64(v_src1);
+            v_sum1 += v_cvt_f64_high(v_src0) + v_cvt_f64_high(v_src1);
+        }
+
+#if CV_SIMD256 || CV_SIMD512
+        double CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[v_float64::nlanes];
+        v_store_aligned(ar, v_sum0 + v_sum1);
+        for (int i = 0; i < v_float64::nlanes; ++i)
+            dst[i % cn] += ar[i];
+#else
+        double CV_DECL_ALIGNED(CV_SIMD_WIDTH) ar[2 * v_float64::nlanes];
+        v_store_aligned(ar, v_sum0);
+        v_store_aligned(ar + v_float64::nlanes, v_sum1);
+        for (int i = 0; i < 2 * v_float64::nlanes; ++i)
+            dst[i % cn] += ar[i];
+#endif
+        v_cleanup();
+
+        return x / cn;
+    }
+};
+#endif
+#endif
+
+template<typename T, typename ST>
+static int sum_(const T* src0, const uchar* mask, ST* dst, int len, int cn )
+{
+    const T* src = src0;
+    if( !mask )
+    {
+        Sum_SIMD<T, ST> vop;
+        int i = vop(src0, mask, dst, len, cn), k = cn % 4;
+        src += i * cn;
+
+        if( k == 1 )
+        {
+            ST s0 = dst[0];
+
+            #if CV_ENABLE_UNROLLED
+            for(; i <= len - 4; i += 4, src += cn*4 )
+                s0 += src[0] + src[cn] + src[cn*2] + src[cn*3];
+            #endif
+            for( ; i < len; i++, src += cn )
+                s0 += src[0];
+            dst[0] = s0;
+        }
+        else if( k == 2 )
+        {
+            ST s0 = dst[0], s1 = dst[1];
+            for( ; i < len; i++, src += cn )
+            {
+                s0 += src[0];
+                s1 += src[1];
+            }
+            dst[0] = s0;
+            dst[1] = s1;
+        }
+        else if( k == 3 )
+        {
+            ST s0 = dst[0], s1 = dst[1], s2 = dst[2];
+            for( ; i < len; i++, src += cn )
+            {
+                s0 += src[0];
+                s1 += src[1];
+                s2 += src[2];
+            }
+            dst[0] = s0;
+            dst[1] = s1;
+            dst[2] = s2;
+        }
+
+        for( ; k < cn; k += 4 )
+        {
+            src = src0 + i*cn + k;
+            ST s0 = dst[k], s1 = dst[k+1], s2 = dst[k+2], s3 = dst[k+3];
+            for( ; i < len; i++, src += cn )
+            {
+                s0 += src[0]; s1 += src[1];
+                s2 += src[2]; s3 += src[3];
+            }
+            dst[k] = s0;
+            dst[k+1] = s1;
+            dst[k+2] = s2;
+            dst[k+3] = s3;
+        }
+        return len;
+    }
+
+    int i, nzm = 0;
+    if( cn == 1 )
+    {
+        ST s = dst[0];
+        for( i = 0; i < len; i++ )
+            if( mask[i] )
+            {
+                s += src[i];
+                nzm++;
+            }
+        dst[0] = s;
+    }
+    else if( cn == 3 )
+    {
+        ST s0 = dst[0], s1 = dst[1], s2 = dst[2];
+        for( i = 0; i < len; i++, src += 3 )
+            if( mask[i] )
+            {
+                s0 += src[0];
+                s1 += src[1];
+                s2 += src[2];
+                nzm++;
+            }
+        dst[0] = s0;
+        dst[1] = s1;
+        dst[2] = s2;
+    }
+    else
+    {
+        for( i = 0; i < len; i++, src += cn )
+            if( mask[i] )
+            {
+                int k = 0;
+                #if CV_ENABLE_UNROLLED
+                for( ; k <= cn - 4; k += 4 )
+                {
+                    ST s0, s1;
+                    s0 = dst[k] + src[k];
+                    s1 = dst[k+1] + src[k+1];
+                    dst[k] = s0; dst[k+1] = s1;
+                    s0 = dst[k+2] + src[k+2];
+                    s1 = dst[k+3] + src[k+3];
+                    dst[k+2] = s0; dst[k+3] = s1;
+                }
+                #endif
+                for( ; k < cn; k++ )
+                    dst[k] += src[k];
+                nzm++;
+            }
+    }
+    return nzm;
+}
+
+
+static int sum8u( const uchar* src, const uchar* mask, int* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum8s( const schar* src, const uchar* mask, int* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum16u( const ushort* src, const uchar* mask, int* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum16s( const short* src, const uchar* mask, int* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum32s( const int* src, const uchar* mask, double* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum32f( const float* src, const uchar* mask, double* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+static int sum64f( const double* src, const uchar* mask, double* dst, int len, int cn )
+{ return sum_(src, mask, dst, len, cn); }
+
+SumFunc getSumFunc(int depth)
+{
+    static SumFunc sumTab[] =
+    {
+        (SumFunc)GET_OPTIMIZED(sum8u), (SumFunc)sum8s,
+        (SumFunc)sum16u, (SumFunc)sum16s,
+        (SumFunc)sum32s,
+        (SumFunc)GET_OPTIMIZED(sum32f), (SumFunc)sum64f,
+        0
+    };
+
+    return sumTab[depth];
+}
+
+#ifdef HAVE_OPENCL
+
+bool ocl_sum( InputArray _src, Scalar & res, int sum_op, InputArray _mask,
+                     InputArray _src2, bool calc2, const Scalar & res2 )
+{
+    CV_Assert(sum_op == OCL_OP_SUM || sum_op == OCL_OP_SUM_ABS || sum_op == OCL_OP_SUM_SQR);
+
+    const ocl::Device & dev = ocl::Device::getDefault();
+    bool doubleSupport = dev.doubleFPConfig() > 0,
+        haveMask = _mask.kind() != _InputArray::NONE,
+        haveSrc2 = _src2.kind() != _InputArray::NONE;
+    int type = _src.type(), depth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type),
+            kercn = cn == 1 && !haveMask ? ocl::predictOptimalVectorWidth(_src, _src2) : 1,
+            mcn = std::max(cn, kercn);
+    CV_Assert(!haveSrc2 || _src2.type() == type);
+    int convert_cn = haveSrc2 ? mcn : cn;
+
+    if ( (!doubleSupport && depth == CV_64F) || cn > 4 )
+        return false;
+
+    int ngroups = dev.maxComputeUnits(), dbsize = ngroups * (calc2 ? 2 : 1);
+    size_t wgs = dev.maxWorkGroupSize();
+
+    int ddepth = std::max(sum_op == OCL_OP_SUM_SQR ? CV_32F : CV_32S, depth),
+            dtype = CV_MAKE_TYPE(ddepth, cn);
+    CV_Assert(!haveMask || _mask.type() == CV_8UC1);
+
+    int wgs2_aligned = 1;
+    while (wgs2_aligned < (int)wgs)
+        wgs2_aligned <<= 1;
+    wgs2_aligned >>= 1;
+
+    static const char * const opMap[3] = { "OP_SUM", "OP_SUM_ABS", "OP_SUM_SQR" };
+    char cvt[2][40];
+    String opts = format("-D srcT=%s -D srcT1=%s -D dstT=%s -D dstTK=%s -D dstT1=%s -D ddepth=%d -D cn=%d"
+                         " -D convertToDT=%s -D %s -D WGS=%d -D WGS2_ALIGNED=%d%s%s%s%s -D kercn=%d%s%s%s -D convertFromU=%s",
+                         ocl::typeToStr(CV_MAKE_TYPE(depth, mcn)), ocl::typeToStr(depth),
+                         ocl::typeToStr(dtype), ocl::typeToStr(CV_MAKE_TYPE(ddepth, mcn)),
+                         ocl::typeToStr(ddepth), ddepth, cn,
+                         ocl::convertTypeStr(depth, ddepth, mcn, cvt[0]),
+                         opMap[sum_op], (int)wgs, wgs2_aligned,
+                         doubleSupport ? " -D DOUBLE_SUPPORT" : "",
+                         haveMask ? " -D HAVE_MASK" : "",
+                         _src.isContinuous() ? " -D HAVE_SRC_CONT" : "",
+                         haveMask && _mask.isContinuous() ? " -D HAVE_MASK_CONT" : "", kercn,
+                         haveSrc2 ? " -D HAVE_SRC2" : "", calc2 ? " -D OP_CALC2" : "",
+                         haveSrc2 && _src2.isContinuous() ? " -D HAVE_SRC2_CONT" : "",
+                         depth <= CV_32S && ddepth == CV_32S ? ocl::convertTypeStr(CV_8U, ddepth, convert_cn, cvt[1]) : "noconvert");
+
+    ocl::Kernel k("reduce", ocl::core::reduce_oclsrc, opts);
+    if (k.empty())
+        return false;
+
+    UMat src = _src.getUMat(), src2 = _src2.getUMat(),
+        db(1, dbsize, dtype), mask = _mask.getUMat();
+
+    ocl::KernelArg srcarg = ocl::KernelArg::ReadOnlyNoSize(src),
+            dbarg = ocl::KernelArg::PtrWriteOnly(db),
+            maskarg = ocl::KernelArg::ReadOnlyNoSize(mask),
+            src2arg = ocl::KernelArg::ReadOnlyNoSize(src2);
+
+    if (haveMask)
+    {
+        if (haveSrc2)
+            k.args(srcarg, src.cols, (int)src.total(), ngroups, dbarg, maskarg, src2arg);
+        else
+            k.args(srcarg, src.cols, (int)src.total(), ngroups, dbarg, maskarg);
+    }
+    else
+    {
+        if (haveSrc2)
+            k.args(srcarg, src.cols, (int)src.total(), ngroups, dbarg, src2arg);
+        else
+            k.args(srcarg, src.cols, (int)src.total(), ngroups, dbarg);
+    }
+
+    size_t globalsize = ngroups * wgs;
+    if (k.run(1, &globalsize, &wgs, false))
+    {
+        typedef Scalar (*part_sum)(Mat m);
+        part_sum funcs[3] = { ocl_part_sum<int>, ocl_part_sum<float>, ocl_part_sum<double> },
+                func = funcs[ddepth - CV_32S];
+
+        Mat mres = db.getMat(ACCESS_READ);
+        if (calc2)
+            const_cast<Scalar &>(res2) = func(mres.colRange(ngroups, dbsize));
+
+        res = func(mres.colRange(0, ngroups));
+        return true;
+    }
+    return false;
+}
+
+#endif
+
+#ifdef HAVE_IPP
+static bool ipp_sum(Mat &src, Scalar &_res)
+{
+    CV_INSTRUMENT_REGION_IPP();
+
+#if IPP_VERSION_X100 >= 700
+    int cn = src.channels();
+    if (cn > 4)
+        return false;
+    size_t total_size = src.total();
+    int rows = src.size[0], cols = rows ? (int)(total_size/rows) : 0;
+    if( src.dims == 2 || (src.isContinuous() && cols > 0 && (size_t)rows*cols == total_size) )
+    {
+        IppiSize sz = { cols, rows };
+        int type = src.type();
+        typedef IppStatus (CV_STDCALL* ippiSumFuncHint)(const void*, int, IppiSize, double *, IppHintAlgorithm);
+        typedef IppStatus (CV_STDCALL* ippiSumFuncNoHint)(const void*, int, IppiSize, double *);
+        ippiSumFuncHint ippiSumHint =
+            type == CV_32FC1 ? (ippiSumFuncHint)ippiSum_32f_C1R :
+            type == CV_32FC3 ? (ippiSumFuncHint)ippiSum_32f_C3R :
+            type == CV_32FC4 ? (ippiSumFuncHint)ippiSum_32f_C4R :
+            0;
+        ippiSumFuncNoHint ippiSum =
+            type == CV_8UC1 ? (ippiSumFuncNoHint)ippiSum_8u_C1R :
+            type == CV_8UC3 ? (ippiSumFuncNoHint)ippiSum_8u_C3R :
+            type == CV_8UC4 ? (ippiSumFuncNoHint)ippiSum_8u_C4R :
+            type == CV_16UC1 ? (ippiSumFuncNoHint)ippiSum_16u_C1R :
+            type == CV_16UC3 ? (ippiSumFuncNoHint)ippiSum_16u_C3R :
+            type == CV_16UC4 ? (ippiSumFuncNoHint)ippiSum_16u_C4R :
+            type == CV_16SC1 ? (ippiSumFuncNoHint)ippiSum_16s_C1R :
+            type == CV_16SC3 ? (ippiSumFuncNoHint)ippiSum_16s_C3R :
+            type == CV_16SC4 ? (ippiSumFuncNoHint)ippiSum_16s_C4R :
+            0;
+        CV_Assert(!ippiSumHint || !ippiSum);
+        if( ippiSumHint || ippiSum )
+        {
+            Ipp64f res[4];
+            IppStatus ret = ippiSumHint ?
+                            CV_INSTRUMENT_FUN_IPP(ippiSumHint, src.ptr(), (int)src.step[0], sz, res, ippAlgHintAccurate) :
+                            CV_INSTRUMENT_FUN_IPP(ippiSum, src.ptr(), (int)src.step[0], sz, res);
+            if( ret >= 0 )
+            {
+                for( int i = 0; i < cn; i++ )
+                    _res[i] = res[i];
+                return true;
+            }
+        }
+    }
+#else
+    CV_UNUSED(src); CV_UNUSED(_res);
+#endif
+    return false;
+}
+#endif
+
+} // cv::
+
+cv::Scalar cv::sum( InputArray _src )
+{
+    CV_INSTRUMENT_REGION();
+
+#if defined HAVE_OPENCL || defined HAVE_IPP
+    Scalar _res;
+#endif
+
+#ifdef HAVE_OPENCL
+    CV_OCL_RUN_(OCL_PERFORMANCE_CHECK(_src.isUMat()) && _src.dims() <= 2,
+                ocl_sum(_src, _res, OCL_OP_SUM),
+                _res)
+#endif
+
+    Mat src = _src.getMat();
+    CV_IPP_RUN(IPP_VERSION_X100 >= 700, ipp_sum(src, _res), _res);
+
+    int k, cn = src.channels(), depth = src.depth();
+    SumFunc func = getSumFunc(depth);
+    CV_Assert( cn <= 4 && func != 0 );
+
+    const Mat* arrays[] = {&src, 0};
+    uchar* ptrs[1] = {};
+    NAryMatIterator it(arrays, ptrs);
+    Scalar s;
+    int total = (int)it.size, blockSize = total, intSumBlockSize = 0;
+    int j, count = 0;
+    AutoBuffer<int> _buf;
+    int* buf = (int*)&s[0];
+    size_t esz = 0;
+    bool blockSum = depth < CV_32S;
+
+    if( blockSum )
+    {
+        intSumBlockSize = depth <= CV_8S ? (1 << 23) : (1 << 15);
+        blockSize = std::min(blockSize, intSumBlockSize);
+        _buf.allocate(cn);
+        buf = _buf.data();
+
+        for( k = 0; k < cn; k++ )
+            buf[k] = 0;
+        esz = src.elemSize();
+    }
+
+    for( size_t i = 0; i < it.nplanes; i++, ++it )
+    {
+        for( j = 0; j < total; j += blockSize )
+        {
+            int bsz = std::min(total - j, blockSize);
+            func( ptrs[0], 0, (uchar*)buf, bsz, cn );
+            count += bsz;
+            if( blockSum && (count + blockSize >= intSumBlockSize || (i+1 >= it.nplanes && j+bsz >= total)) )
+            {
+                for( k = 0; k < cn; k++ )
+                {
+                    s[k] += buf[k];
+                    buf[k] = 0;
+                }
+                count = 0;
+            }
+            ptrs[0] += bsz*esz;
+        }
+    }
+    return s;
+}