Merge remote-tracking branch 'upstream/3.4' into merge-3.4

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

@@ -449,7 +449,16 @@ CV_EXPORTS InputOutputArray noArray();
 
 /////////////////////////////////// MatAllocator //////////////////////////////////////
 
-//! Usage flags for allocator
+/** @brief  Usage flags for allocator
+
+ @warning  All flags except `USAGE_DEFAULT` are experimental.
+
+ @warning  For the OpenCL allocator, `USAGE_ALLOCATE_SHARED_MEMORY` depends on
+ OpenCV's optional, experimental integration with OpenCL SVM. To enable this
+ integration, build OpenCV using the `WITH_OPENCL_SVM=ON` CMake option and, at
+ runtime, call `cv::ocl::Context::getDefault().setUseSVM(true);` or similar
+ code. Note that SVM is incompatible with OpenCL 1.x.
+*/
 enum UMatUsageFlags
 {
     USAGE_DEFAULT = 0,
@@ -2077,7 +2086,7 @@ public:
 
         Mat_<Pixel> image = Mat::zeros(3, sizes, CV_8UC3);
 
-        image.forEach<Pixel>([&](Pixel& pixel, const int position[]) -> void {
+        image.forEach<Pixel>([](Pixel& pixel, const int position[]) -> void {
             pixel.x = position[0];
             pixel.y = position[1];
             pixel.z = position[2];

modules/core/src/kmeans.cpp

@@ -240,7 +240,7 @@ double cv::kmeans( InputArray _data, int K,
 
     attempts = std::max(attempts, 1);
     CV_Assert( data0.dims <= 2 && type == CV_32F && K > 0 );
-    CV_CheckGE(N, K, "Number of clusters should be more than number of elements");
+    CV_CheckGE(N, K, "There can't be more clusters than elements");
 
     Mat data(N, dims, CV_32F, data0.ptr(), isrow ? dims * sizeof(float) : static_cast<size_t>(data0.step));
 

modules/core/src/matrix.cpp

@@ -269,7 +269,7 @@ void setSize( Mat& m, int _dims, const int* _sz, const size_t* _steps, bool auto
         else if( autoSteps )
         {
             m.step.p[i] = total;
-            int64 total1 = (int64)total*s;
+            uint64 total1 = (uint64)total*s;
             if( (uint64)total1 != (size_t)total1 )
                 CV_Error( CV_StsOutOfRange, "The total matrix size does not fit to \"size_t\" type" );
             total = (size_t)total1;