diff --git a/modules/imgproc/src/opencl/match_template.cl b/modules/imgproc/src/opencl/match_template.cl
index 1919e8edd2..c6c9468e88 100644
--- a/modules/imgproc/src/opencl/match_template.cl
+++ b/modules/imgproc/src/opencl/match_template.cl
@@ -90,11 +90,8 @@ __kernel void calcSum(__global const uchar * srcptr, int src_step, int src_offse
         T src = loadpix(srcptr + src_index);
 
         tmp = convertToWT(src);
-#if wdepth == 4
-        accumulator = mad24(tmp, tmp, accumulator);
-#else
+
         accumulator = mad(tmp, tmp, accumulator);
-#endif
     }
 
     if (lid < WGS2_ALIGNED)
@@ -165,11 +162,9 @@ __kernel void matchTemplate_Naive_CCORR(__global const uchar * srcptr, int src_s
                 {
                     T temp = (T)(template[j]);
                     T src = *(__global const T*)(srcptr + ind + j*(int)sizeof(T1));
-#if wdepth == 4
-                        sum = mad24(convertToWT(src), convertToWT(temp), sum);
-#else
-                        sum = mad(convertToWT(src), convertToWT(temp), sum);
-#endif
+
+                    sum = mad(convertToWT(src), convertToWT(temp), sum);
+
                 }
             ind += src_step;
             template = (__global const T1 *)((__global const uchar *)template + template_step);
@@ -195,12 +190,7 @@ __kernel void matchTemplate_Naive_CCORR(__global const uchar * srcptr, int src_s
                     #pragma unroll
                     for (int cx=0, x = x0; cx < PIX_PER_WI_X && x < dst_cols; ++cx, ++x)
                     {
-
-#if wdepth == 4
-                        sum[cx] = mad24(convertToWT1(src[j+cx]), convertToWT1(template[j]), sum[cx]);
-#else
                         sum[cx] = mad(convertToWT1(src[j+cx]), convertToWT1(template[j]), sum[cx]);
-#endif
                     }
                 }
 
@@ -237,11 +227,8 @@ __kernel void matchTemplate_Naive_CCORR(__global const uchar * srcptr, int src_s
             {
                 T src      = loadpix(srcptr      + mad24(y+i, src_step,    mad24(x+j, TSIZE, src_offset)));
                 T template = loadpix(templateptr + mad24(i, template_step, mad24(j, TSIZE, template_offset)));
-#if wdepth == 4
-                sum = mad24(convertToWT(src), convertToWT(template), sum);
-#else
+
                 sum = mad(convertToWT(src), convertToWT(template), sum);
-#endif
             }
         }
 
@@ -296,11 +283,8 @@ __kernel void matchTemplate_Naive_SQDIFF(__global const uchar * srcptr, int src_
                 T template = loadpix(templateptr + mad24(i, template_step, mad24(j, TSIZE, template_offset)));
 
                 value = convertToWT(src) - convertToWT(template);
-#if wdepth == 4
-                sum = mad24(value, value, sum);
-#else
+
                 sum = mad(value, value, sum);
-#endif
             }
         }
 
diff --git a/modules/imgproc/src/templmatch.cpp b/modules/imgproc/src/templmatch.cpp
index 164af425e3..45f2529f7a 100644
--- a/modules/imgproc/src/templmatch.cpp
+++ b/modules/imgproc/src/templmatch.cpp
@@ -79,7 +79,7 @@ static bool extractFirstChannel_32F(InputArray _image, OutputArray _result, int
 static bool sumTemplate(InputArray _src, UMat & result)
 {
     int type = _src.type(), depth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type);
-    int wdepth = std::max(CV_32S, depth), wtype = CV_MAKE_TYPE(wdepth, cn);
+    int wdepth = CV_32F, wtype = CV_MAKE_TYPE(wdepth, cn);
     size_t wgs = ocl::Device::getDefault().maxWorkGroupSize();
 
     int wgs2_aligned = 1;
@@ -89,10 +89,10 @@ static bool sumTemplate(InputArray _src, UMat & result)
 
     char cvt[40];
     ocl::Kernel k("calcSum", ocl::imgproc::match_template_oclsrc,
-                  format("-D CALC_SUM -D T=%s -D T1=%s -D WT=%s -D cn=%d -D convertToWT=%s -D WGS=%d -D WGS2_ALIGNED=%d -D wdepth=%d",
+                  format("-D CALC_SUM -D T=%s -D T1=%s -D WT=%s -D cn=%d -D convertToWT=%s -D WGS=%d -D WGS2_ALIGNED=%d",
                          ocl::typeToStr(type), ocl::typeToStr(depth), ocl::typeToStr(wtype), cn,
                          ocl::convertTypeStr(depth, wdepth, cn, cvt),
-                         (int)wgs, wgs2_aligned, wdepth));
+                         (int)wgs, wgs2_aligned));
     if (k.empty())
         return false;
 
@@ -110,12 +110,8 @@ static bool sumTemplate(InputArray _src, UMat & result)
 
 static bool useNaive(Size size)
 {
-    if (!ocl::Device::getDefault().isIntel())
-        return true;
-
     int dft_size = 18;
     return size.height < dft_size && size.width < dft_size;
-
 }
 
 struct ConvolveBuf
@@ -129,7 +125,6 @@ struct ConvolveBuf
     UMat image_block, templ_block, result_data;
 
     void create(Size image_size, Size templ_size);
-    static Size estimateBlockSize(Size result_size);
 };
 
 void ConvolveBuf::create(Size image_size, Size templ_size)
@@ -137,19 +132,26 @@ void ConvolveBuf::create(Size image_size, Size templ_size)
     result_size = Size(image_size.width - templ_size.width + 1,
                        image_size.height - templ_size.height + 1);
 
-    block_size = user_block_size;
-    if (user_block_size.width == 0 || user_block_size.height == 0)
-        block_size = estimateBlockSize(result_size);
+    const double blockScale = 4.5;
+    const int minBlockSize = 256;
 
-    dft_size.width  = 1 << int(ceil(std::log(block_size.width + templ_size.width - 1.) / std::log(2.)));
-    dft_size.height = 1 << int(ceil(std::log(block_size.height + templ_size.height - 1.) / std::log(2.)));
+    block_size.width = cvRound(result_size.width*blockScale);
+    block_size.width = std::max( block_size.width, minBlockSize - templ_size.width + 1 );
+    block_size.width = std::min( block_size.width, result_size.width );
+    block_size.height = cvRound(templ_size.height*blockScale);
+    block_size.height = std::max( block_size.height, minBlockSize - templ_size.height + 1 );
+    block_size.height = std::min( block_size.height, result_size.height );
 
-    dft_size.width = getOptimalDFTSize(block_size.width + templ_size.width - 1);
+    dft_size.width = std::max(getOptimalDFTSize(block_size.width + templ_size.width - 1), 2);
     dft_size.height = getOptimalDFTSize(block_size.height + templ_size.height - 1);
+    if( dft_size.width <= 0 || dft_size.height <= 0 )
+        CV_Error( CV_StsOutOfRange, "the input arrays are too big" );
 
-    // To avoid wasting time doing small DFTs
-    dft_size.width = std::max(dft_size.width, 512);
-    dft_size.height = std::max(dft_size.height, 512);
+    // recompute block size
+    block_size.width = dft_size.width - templ_size.width + 1;
+    block_size.width = std::min( block_size.width, result_size.width);
+    block_size.height = dft_size.height - templ_size.height + 1;
+    block_size.height = std::min( block_size.height, result_size.height );
 
     image_block.create(dft_size, CV_32F);
     templ_block.create(dft_size, CV_32F);
@@ -164,15 +166,6 @@ void ConvolveBuf::create(Size image_size, Size templ_size)
     block_size.height = std::min(dft_size.height - templ_size.height + 1, result_size.height);
 }
 
-Size ConvolveBuf::estimateBlockSize(Size result_size)
-{
-    int width = (result_size.width + 2) / 3;
-    int height = (result_size.height + 2) / 3;
-    width = std::min(width, result_size.width);
-    height = std::min(height, result_size.height);
-    return Size(width, height);
-}
-
 static bool convolve_dft(InputArray _image, InputArray _templ, OutputArray _result)
 {
     ConvolveBuf buf;
@@ -202,7 +195,7 @@ static bool convolve_dft(InputArray _image, InputArray _templ, OutputArray _resu
     copyMakeBorder(templ_roi, templ_block, 0, templ_block.rows - templ_roi.rows, 0,
                    templ_block.cols - templ_roi.cols, BORDER_ISOLATED);
 
-    dft(templ_block, templ_spect, 0);
+    dft(templ_block, templ_spect, 0, templ.rows);
 
     // Process all blocks of the result matrix
     for (int y = 0; y < result.rows; y += block_size.height)
@@ -281,8 +274,8 @@ static bool matchTemplateNaive_CCORR(InputArray _image, InputArray _templ, Outpu
     const char* convertToWT = ocl::convertTypeStr(depth, wdepth, rated_cn, cvt1);
 
     ocl::Kernel k("matchTemplate_Naive_CCORR", ocl::imgproc::match_template_oclsrc,
-                  format("-D CCORR -D T=%s -D T1=%s -D WT=%s -D WT1=%s -D convertToWT=%s -D convertToWT1=%s -D cn=%d -D wdepth=%d -D PIX_PER_WI_X=%d", ocl::typeToStr(type), ocl::typeToStr(depth), ocl::typeToStr(wtype1), ocl::typeToStr(wtype),
-                         convertToWT, convertToWT1, cn, wdepth, pxPerWIx));
+                  format("-D CCORR -D T=%s -D T1=%s -D WT=%s -D WT1=%s -D convertToWT=%s -D convertToWT1=%s -D cn=%d -D PIX_PER_WI_X=%d", ocl::typeToStr(type), ocl::typeToStr(depth), ocl::typeToStr(wtype1), ocl::typeToStr(wtype),
+                         convertToWT, convertToWT1, cn, pxPerWIx));
     if (k.empty())
         return false;
 
@@ -358,8 +351,8 @@ static bool matchTemplateNaive_SQDIFF(InputArray _image, InputArray _templ, Outp
 
     char cvt[40];
     ocl::Kernel k("matchTemplate_Naive_SQDIFF", ocl::imgproc::match_template_oclsrc,
-                  format("-D SQDIFF -D T=%s -D T1=%s -D WT=%s -D convertToWT=%s -D cn=%d -D wdepth=%d", ocl::typeToStr(type), ocl::typeToStr(depth),
-                         ocl::typeToStr(wtype), ocl::convertTypeStr(depth, wdepth, cn, cvt), cn, wdepth));
+                  format("-D SQDIFF -D T=%s -D T1=%s -D WT=%s -D convertToWT=%s -D cn=%d", ocl::typeToStr(type), ocl::typeToStr(depth),
+                         ocl::typeToStr(wtype), ocl::convertTypeStr(depth, wdepth, cn, cvt), cn));
     if (k.empty())
         return false;