OpenCL version of cv::buildPyramid

modules/core/include/opencv2/core/mat.hpp

@@ -207,6 +207,7 @@ public:
     virtual bool fixedType() const;
     virtual bool needed() const;
     virtual Mat& getMatRef(int i=-1) const;
+    virtual UMat& getUMatRef(int i=-1) const;
     virtual cuda::GpuMat& getGpuMatRef() const;
     virtual ogl::Buffer& getOGlBufferRef() const;
     virtual cuda::CudaMem& getCudaMemRef() const;

modules/core/src/matrix.cpp

@@ -2484,6 +2484,23 @@ Mat& _OutputArray::getMatRef(int i) const
     }
 }
 
+UMat& _OutputArray::getUMatRef(int i) const
+{
+    int k = kind();
+    if( i < 0 )
+    {
+        CV_Assert( k == UMAT );
+        return *(UMat*)obj;
+    }
+    else
+    {
+        CV_Assert( k == STD_VECTOR_UMAT );
+        std::vector<UMat>& v = *(std::vector<UMat>*)obj;
+        CV_Assert( i < (int)v.size() );
+        return v[i];
+    }
+}
+
 cuda::GpuMat& _OutputArray::getGpuMatRef() const
 {
     int k = kind();

modules/imgproc/perf/opencl/perf_pyramid.cpp

@@ -100,6 +100,35 @@ OCL_PERF_TEST_P(PyrUpFixture, PyrUp,
     SANITY_CHECK(dst, eps);
 }
 
+///////////// buildPyramid ////////////////////////
+
+typedef Size_MatType BuildPyramidFixture;
+
+OCL_PERF_TEST_P(BuildPyramidFixture, BuildPyramid,
+                ::testing::Combine(OCL_TEST_SIZES, OCL_TEST_TYPES))
+{
+    const Size_MatType_t params = GetParam();
+    const Size srcSize = get<0>(params);
+    const int type = get<1>(params), maxLevel = 5;
+    const double eps = CV_MAT_DEPTH(type) <= CV_32S ? 1 : 1e-5;
+
+    checkDeviceMaxMemoryAllocSize(srcSize, type);
+
+    std::vector<UMat> dst(maxLevel);
+    UMat src(srcSize, type);
+    declare.in(src, WARMUP_RNG);
+
+    OCL_TEST_CYCLE() cv::buildPyramid(src, dst, maxLevel);
+
+    UMat dst0 = dst[0], dst1 = dst[1], dst2 = dst[2], dst3 = dst[3], dst4 = dst[4];
+
+    SANITY_CHECK(dst0, eps);
+    SANITY_CHECK(dst1, eps);
+    SANITY_CHECK(dst2, eps);
+    SANITY_CHECK(dst3, eps);
+    SANITY_CHECK(dst4, eps);
+}
+
 } } // namespace cvtest::ocl
 
 #endif // HAVE_OPENCL

modules/imgproc/src/pyramids.cpp

@@ -556,6 +556,16 @@ void cv::pyrUp( InputArray _src, OutputArray _dst, const Size& _dsz, int borderT
 
 void cv::buildPyramid( InputArray _src, OutputArrayOfArrays _dst, int maxlevel, int borderType )
 {
+    if (_src.dims() <= 2 && _dst.isUMatVector())
+    {
+        UMat src = _src.getUMat();
+        _dst.create( maxlevel + 1, 1, 0 );
+        _dst.getUMatRef(0) = src;
+        for( int i = 1; i <= maxlevel; i++ )
+            pyrDown( _dst.getUMatRef(i-1), _dst.getUMatRef(i), Size(), borderType );
+        return;
+    }
+
     Mat src = _src.getMat();
     _dst.create( maxlevel + 1, 1, 0 );
     _dst.getMatRef(0) = src;