All CUDA related stuff were moved to separate dynamic library.

modules/core/CMakeLists.txt

 set(the_description "The Core Functionality")
-ocv_add_module(core PRIVATE_REQUIRED ${ZLIB_LIBRARIES})
-ocv_module_include_directories(${ZLIB_INCLUDE_DIR})
 
 if(HAVE_WINRT)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /ZW /GS /Gm- /AI\"${WINDOWS_SDK_PATH}/References/CommonConfiguration/Neutral\" /AI\"${VISUAL_STUDIO_PATH}/vcpackages\"")
 endif()
 
-if(HAVE_CUDA)
-  ocv_include_directories("${OpenCV_SOURCE_DIR}/modules/gpu/include")
-  ocv_warnings_disable(CMAKE_CXX_FLAGS -Wundef)
-endif()
-
 file(GLOB lib_cuda_hdrs        "include/opencv2/${name}/cuda/*.hpp"        "include/opencv2/${name}/cuda/*.h")
 file(GLOB lib_cuda_hdrs_detail "include/opencv2/${name}/cuda/detail/*.hpp" "include/opencv2/${name}/cuda/detail/*.h")
 
 source_group("Cuda Headers"         FILES ${lib_cuda_hdrs})
 source_group("Cuda Headers\\Detail" FILES ${lib_cuda_hdrs_detail})
 
+if(DYNAMIC_CUDA_SUPPORT)
+  add_definitions(-DDYNAMIC_CUDA_SUPPORT)
+endif()
+
+ocv_add_module(core PRIVATE_REQUIRED ${ZLIB_LIBRARIES})
+ocv_module_include_directories(${ZLIB_INCLUDE_DIR})
+
+if(HAVE_CUDA)
+  ocv_include_directories("${OpenCV_SOURCE_DIR}/modules/gpu/include")
+  ocv_warnings_disable(CMAKE_CXX_FLAGS -Wundef)
+endif()
+
 ocv_glob_module_sources(SOURCES "${opencv_core_BINARY_DIR}/version_string.inc"
                         HEADERS ${lib_cuda_hdrs} ${lib_cuda_hdrs_detail})
 
@@ -25,3 +30,7 @@ ocv_add_precompiled_headers(${the_module})
 
 ocv_add_accuracy_tests()
 ocv_add_perf_tests()
+
+if(DYNAMIC_CUDA_SUPPORT)
+  add_subdirectory(cuda)
+endif()

modules/core/cuda/CMakeLists.txt

+project(opencv_core_cuda)
+set(HAVE_CUDA FALSE)
+add_definitions("-DHAVE_CUDA")
+include_directories(${CUDA_INCLUDE_DIRS}
+                    "../src/"
+                    "../include/opencv2/core/"
+                    "${OpenCV_SOURCE_DIR}/modules/gpu/include"
+                   )
+ocv_warnings_disable(CMAKE_CXX_FLAGS -Wundef)
+cuda_add_library(opencv_core_cuda SHARED main.cpp ../src/cuda/matrix_operations.cu)
+target_link_libraries(opencv_core_cuda ${CUDA_LIBRARIES})
\ No newline at end of file

modules/core/cuda/main.cpp

+#include "opencv2/core/core.hpp"
+#include "opencv2/core/gpumat.hpp"
+
+#ifdef HAVE_CUDA
+#include <cuda_runtime.h>
+#include <npp.h>
+
+#define CUDART_MINIMUM_REQUIRED_VERSION 4020
+#define NPP_MINIMUM_REQUIRED_VERSION 4200
+
+#if (CUDART_VERSION < CUDART_MINIMUM_REQUIRED_VERSION)
+#error "Insufficient Cuda Runtime library version, please update it."
+#endif
+
+#if (NPP_VERSION_MAJOR * 1000 + NPP_VERSION_MINOR * 100 + NPP_VERSION_BUILD < NPP_MINIMUM_REQUIRED_VERSION)
+#error "Insufficient NPP version, please update it."
+#endif
+#endif
+
+using namespace cv;
+using namespace cv::gpu;
+
+#include "gpumat_cuda.hpp"
\ No newline at end of file

modules/core/include/opencv2/core/gpumat.hpp

@@ -48,6 +48,8 @@
 #include "opencv2/core/core.hpp"
 #include "opencv2/core/cuda_devptrs.hpp"
 
+#define throw_nogpu CV_Error(CV_GpuNotSupported, "The library is compiled without CUDA support")
+
 namespace cv { namespace gpu
 {
     //////////////////////////////// Initialization & Info ////////////////////////