diff --git a/modules/core/include/opencv2/core/mat.hpp b/modules/core/include/opencv2/core/mat.hpp
index 5c5284f8d..3133876e4 100644
--- a/modules/core/include/opencv2/core/mat.hpp
+++ b/modules/core/include/opencv2/core/mat.hpp
@@ -497,6 +497,7 @@ struct CV_EXPORTS UMatData
     void* userdata;
     int allocatorFlags_;
     int mapcount;
+    UMatData* originalUMatData;
 };
 
 
diff --git a/modules/core/src/matrix.cpp b/modules/core/src/matrix.cpp
index c0ad8c4ec..9d9dda329 100644
--- a/modules/core/src/matrix.cpp
+++ b/modules/core/src/matrix.cpp
@@ -208,17 +208,14 @@ public:
         if(!u)
             return;
 
-        CV_Assert(u->urefcount >= 0);
-        CV_Assert(u->refcount >= 0);
-        if(u->refcount == 0)
+        CV_Assert(u->urefcount == 0);
+        CV_Assert(u->refcount == 0);
+        if( !(u->flags & UMatData::USER_ALLOCATED) )
         {
-            if( !(u->flags & UMatData::USER_ALLOCATED) )
-            {
-                fastFree(u->origdata);
-                u->origdata = 0;
-            }
-            delete u;
+            fastFree(u->origdata);
+            u->origdata = 0;
         }
+        delete u;
     }
 };
 
diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index f6e27302f..1345c52e3 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -4453,8 +4453,11 @@ public:
 #endif
             {
                 tempUMatFlags = UMatData::TEMP_UMAT;
-                handle = clCreateBuffer(ctx_handle, CL_MEM_USE_HOST_PTR|createFlags,
-                                           u->size, u->origdata, &retval);
+                if (u->origdata == cv::alignPtr(u->origdata, 4)) // There are OpenCL runtime issues for less aligned data
+                {
+                    handle = clCreateBuffer(ctx_handle, CL_MEM_USE_HOST_PTR|createFlags,
+                                            u->size, u->origdata, &retval);
+                }
                 if((!handle || retval < 0) && !(accessFlags & ACCESS_FAST))
                 {
                     handle = clCreateBuffer(ctx_handle, CL_MEM_COPY_HOST_PTR|CL_MEM_READ_WRITE|createFlags,
@@ -4510,17 +4513,17 @@ public:
         if(!u)
             return;
 
-        CV_Assert(u->urefcount >= 0);
-        CV_Assert(u->refcount >= 0);
+        CV_Assert(u->urefcount == 0);
+        CV_Assert(u->refcount == 0 && "UMat deallocation error: some derived Mat is still alive");
 
-        CV_Assert(u->handle != 0 && u->urefcount == 0);
+        CV_Assert(u->handle != 0);
         CV_Assert(u->mapcount == 0);
         if(u->tempUMat())
         {
             CV_Assert(u->origdata);
 //            UMatDataAutoLock lock(u);
 
-            if( u->hostCopyObsolete() && u->refcount > 0 )
+            if (u->hostCopyObsolete())
             {
 #ifdef HAVE_OPENCL_SVM
                 if ((u->allocatorFlags_ & svm::OPENCL_SVM_BUFFER_MASK) != 0)
@@ -4579,7 +4582,12 @@ public:
                             void* data = clEnqueueMapBuffer(q, (cl_mem)u->handle, CL_TRUE,
                                 (CL_MAP_READ | CL_MAP_WRITE),
                                 0, u->size, 0, 0, 0, &retval);
+                            CV_Assert(u->origdata == data);
                             CV_OclDbgAssert(retval == CL_SUCCESS);
+                            if (u->originalUMatData)
+                            {
+                                CV_Assert(u->originalUMatData->data == data);
+                            }
                             CV_OclDbgAssert(clEnqueueUnmapMemObject(q, (cl_mem)u->handle, data, 0, 0, 0) == CL_SUCCESS);
                             CV_OclDbgAssert(clFinish(q) == CL_SUCCESS);
                         }
@@ -4587,6 +4595,10 @@ public:
                 }
                 u->markHostCopyObsolete(false);
             }
+            else
+            {
+                // nothing
+            }
 #ifdef HAVE_OPENCL_SVM
             if ((u->allocatorFlags_ & svm::OPENCL_SVM_BUFFER_MASK) != 0)
             {
@@ -4612,16 +4624,12 @@ public:
             if(u->data && u->copyOnMap() && u->data != u->origdata)
                 fastFree(u->data);
             u->data = u->origdata;
-            if(u->refcount == 0)
-            {
-                u->currAllocator->deallocate(u);
-                u = NULL;
-            }
+            u->currAllocator->deallocate(u);
+            u = NULL;
         }
         else
         {
             CV_Assert(u->origdata == NULL);
-            CV_Assert(u->refcount == 0);
             if(u->data && u->copyOnMap() && u->data != u->origdata)
             {
                 fastFree(u->data);
@@ -4670,17 +4678,13 @@ public:
             delete u;
             u = NULL;
         }
-        CV_Assert(u == NULL || u->refcount);
+        CV_Assert(u == NULL);
     }
 
+    // synchronized call (external UMatDataAutoLock, see UMat::getMat)
     void map(UMatData* u, int accessFlags) const
     {
-        if(!u)
-            return;
-
-        CV_Assert( u->handle != 0 );
-
-        UMatDataAutoLock autolock(u);
+        CV_Assert(u && u->handle);
 
         if(accessFlags & ACCESS_WRITE)
             u->markDeviceCopyObsolete(true);
diff --git a/modules/core/src/umatrix.cpp b/modules/core/src/umatrix.cpp
index b7c60726a..7bfeff1df 100644
--- a/modules/core/src/umatrix.cpp
+++ b/modules/core/src/umatrix.cpp
@@ -67,6 +67,7 @@ UMatData::UMatData(const MatAllocator* allocator)
     handle = 0;
     userdata = 0;
     allocatorFlags_ = 0;
+    originalUMatData = NULL;
 }
 
 UMatData::~UMatData()
@@ -80,6 +81,50 @@ UMatData::~UMatData()
     handle = 0;
     userdata = 0;
     allocatorFlags_ = 0;
+    if (originalUMatData)
+    {
+        UMatData* u = originalUMatData;
+        CV_XADD(&(u->urefcount), -1);
+        CV_XADD(&(u->refcount), -1);
+        bool showWarn = false;
+        if (u->refcount == 0)
+        {
+            if (u->urefcount > 0)
+                showWarn = true;
+            // simulate Mat::deallocate
+            if (u->mapcount != 0)
+            {
+                (u->currAllocator ? u->currAllocator : /* TODO allocator ? allocator :*/ Mat::getStdAllocator())->unmap(u);
+            }
+            else
+            {
+                // we don't do "map", so we can't do "unmap"
+            }
+        }
+        if (u->refcount == 0 && u->urefcount == 0) // oops, we need to free resources
+        {
+            showWarn = true;
+            // simulate UMat::deallocate
+            u->currAllocator->deallocate(u);
+        }
+#ifndef NDEBUG
+        if (showWarn)
+        {
+            static int warn_message_showed = 0;
+            if (warn_message_showed++ < 100)
+            {
+                fflush(stdout);
+                fprintf(stderr, "\n! OPENCV warning: getUMat()/getMat() call chain possible problem."
+                                "\n!                 Base object is dead, while nested/derived object is still alive or processed."
+                                "\n!                 Please check lifetime of UMat/Mat objects!\n");
+                fflush(stderr);
+            }
+        }
+#else
+        (void)showWarn;
+#endif
+        originalUMatData = NULL;
+    }
 }
 
 void UMatData::lock()
@@ -222,20 +267,34 @@ UMat Mat::getUMat(int accessFlags, UMatUsageFlags usageFlags) const
     UMat hdr;
     if(!data)
         return hdr;
-    CV_Assert((!u || u->mapcount==0) && "Don't get UMat from temp-Mat!");
+    Size wholeSize;
+    Point ofs;
+    locateROI(wholeSize, ofs);
+    Size sz(cols, rows);
+    if (ofs.x != 0 || ofs.y != 0)
+    {
+        Mat src = *this;
+        int dtop = ofs.y;
+        int dbottom = wholeSize.height - src.rows - ofs.y;
+        int dleft = ofs.x;
+        int dright = wholeSize.width - src.cols - ofs.x;
+        src.adjustROI(dtop, dbottom, dleft, dright);
+        return src.getUMat(accessFlags, usageFlags)(cv::Rect(ofs.x, ofs.y, sz.width, sz.height));
+    }
+    CV_Assert(data == datastart);
+
     accessFlags |= ACCESS_RW;
-    UMatData* temp_u = u;
-    if(!temp_u)
+    UMatData* new_u = NULL;
     {
         MatAllocator *a = allocator, *a0 = getStdAllocator();
         if(!a)
             a = a0;
-        temp_u = a->allocate(dims, size.p, type(), data, step.p, accessFlags, usageFlags);
+        new_u = a->allocate(dims, size.p, type(), data, step.p, accessFlags, usageFlags);
     }
     bool allocated = false;
     try
     {
-        allocated = UMat::getStdAllocator()->allocate(temp_u, accessFlags, usageFlags);
+        allocated = UMat::getStdAllocator()->allocate(new_u, accessFlags, usageFlags);
     }
     catch (const cv::Exception& e)
     {
@@ -243,14 +302,26 @@ UMat Mat::getUMat(int accessFlags, UMatUsageFlags usageFlags) const
     }
     if (!allocated)
     {
-        allocated = getStdAllocator()->allocate(temp_u, accessFlags, usageFlags);
+        allocated = getStdAllocator()->allocate(new_u, accessFlags, usageFlags);
         CV_Assert(allocated);
     }
+    if (u != NULL)
+    {
+#ifdef HAVE_OPENCL
+        if (ocl::useOpenCL() && new_u->currAllocator == ocl::getOpenCLAllocator())
+        {
+            CV_Assert(new_u->tempUMat());
+        }
+#endif
+        new_u->originalUMatData = u;
+        CV_XADD(&(u->refcount), 1);
+        CV_XADD(&(u->urefcount), 1);
+    }
     hdr.flags = flags;
     setSize(hdr, dims, size.p, step.p);
     finalizeHdr(hdr);
-    hdr.u = temp_u;
-    hdr.offset = data - datastart;
+    hdr.u = new_u;
+    hdr.offset = 0; //data - datastart;
     hdr.addref();
     return hdr;
 }
@@ -639,7 +710,6 @@ Mat UMat::getMat(int accessFlags) const
 {
     if(!u)
         return Mat();
-    CV_Assert(!u->tempUMat() && "Don't get Mat from temp UMat! Use copyTo().");
     // TODO Support ACCESS_READ (ACCESS_WRITE) without unnecessary data transfers
     accessFlags |= ACCESS_RW;
     UMatDataAutoLock autolock(u);
@@ -668,10 +738,10 @@ void* UMat::handle(int accessFlags) const
     if( !u )
         return 0;
 
-    // check flags: if CPU copy is newer, copy it back to GPU.
-    if( u->deviceCopyObsolete() )
+    CV_Assert(u->refcount == 0);
+    CV_Assert(!u->deviceCopyObsolete() || u->copyOnMap());
+    if (u->deviceCopyObsolete())
     {
-        CV_Assert(u->refcount == 0 || u->origdata);
         u->currAllocator->unmap(u);
     }
 
diff --git a/modules/core/test/test_umat.cpp b/modules/core/test/test_umat.cpp
index 7c1310dd0..bdd38a0a1 100644
--- a/modules/core/test/test_umat.cpp
+++ b/modules/core/test/test_umat.cpp
@@ -263,7 +263,7 @@ TEST_P(UMatBasicTests, GetUMat)
     }
 }
 
-INSTANTIATE_TEST_CASE_P(UMat, UMatBasicTests, Combine(testing::Values(CV_8U), testing::Values(1, 2),
+INSTANTIATE_TEST_CASE_P(UMat, UMatBasicTests, Combine(testing::Values(CV_8U, CV_64F), testing::Values(1, 2),
     testing::Values(cv::Size(1, 1), cv::Size(1, 128), cv::Size(128, 1), cv::Size(128, 128), cv::Size(640, 480)), Bool()));
 
 //////////////////////////////////////////////////////////////// Reshape ////////////////////////////////////////////////////////////////////////
@@ -1084,7 +1084,7 @@ TEST(UMat, unmap_in_class)
                 Mat dst;
                 m.convertTo(dst, CV_32FC1);
                 // some additional CPU-based per-pixel processing into dst
-                intermediateResult = dst.getUMat(ACCESS_READ);
+                intermediateResult = dst.getUMat(ACCESS_READ); // this violates lifetime of base(dst) / derived (intermediateResult) objects. Use copyTo?
                 std::cout << "data processed..." << std::endl;
             } // problem is here: dst::~Mat()
             std::cout << "leave ProcessData()" << std::endl;
@@ -1285,4 +1285,48 @@ TEST(UMat, mat_umat_sync)
     ASSERT_EQ(0, countNonZero(uDiff));
 }
 
+TEST(UMat, testTempObjects_UMat)
+{
+    UMat u(10, 10, CV_8UC1, Scalar(1));
+    {
+        UMat u2 = u.getMat(ACCESS_RW).getUMat(ACCESS_RW);
+        u2.setTo(Scalar(255));
+    }
+
+    UMat uDiff;
+    compare(u, 255, uDiff, CMP_NE);
+    ASSERT_EQ(0, countNonZero(uDiff));
+}
+
+TEST(UMat, testTempObjects_Mat)
+{
+    Mat m(10, 10, CV_8UC1, Scalar(1));
+    {
+        Mat m2;
+        ASSERT_ANY_THROW(m2 = m.getUMat(ACCESS_RW).getMat(ACCESS_RW));
+    }
+}
+
+TEST(UMat, testWrongLifetime_UMat)
+{
+    UMat u(10, 10, CV_8UC1, Scalar(1));
+    {
+        UMat u2 = u.getMat(ACCESS_RW).getUMat(ACCESS_RW);
+        u.release(); // base object
+        u2.release(); // derived object, should show warning message
+    }
+}
+
+TEST(UMat, testWrongLifetime_Mat)
+{
+    Mat m(10, 10, CV_8UC1, Scalar(1));
+    {
+        UMat u = m.getUMat(ACCESS_RW);
+        Mat m2 = u.getMat(ACCESS_RW);
+        m.release(); // base object
+        m2.release(); // map of derived object
+        u.release(); // derived object, should show warning message
+    }
+}
+
 } } // namespace cvtest::ocl
diff --git a/modules/video/src/lkpyramid.cpp b/modules/video/src/lkpyramid.cpp
index 43dde7df7..a34e73d51 100644
--- a/modules/video/src/lkpyramid.cpp
+++ b/modules/video/src/lkpyramid.cpp
@@ -1009,7 +1009,7 @@ namespace cv
             idxArg = kernel.set(idxArg, (int)winSize.height); // int c_winSize_y
             idxArg = kernel.set(idxArg, (int)iters); // int c_iters
             idxArg = kernel.set(idxArg, (char)calcErr); //char calcErr
-            return kernel.run(2, globalThreads, localThreads, false);
+            return kernel.run(2, globalThreads, localThreads, true); // sync=true because ocl::Image2D lifetime is not handled well for temp UMat
         }
     private:
         inline static bool isDeviceCPU()