diff -Nuarp opencv-3.4.20.orig/cmake/OpenCVGenConfig.cmake opencv-3.4.20/cmake/OpenCVGenConfig.cmake
--- opencv-3.4.20.orig/cmake/OpenCVGenConfig.cmake	2023-06-27 19:29:13.000000000 +0800
+++ opencv-3.4.20/cmake/OpenCVGenConfig.cmake	2023-08-30 11:59:03.095856713 +0800
@@ -15,6 +15,10 @@ if(HAVE_CUDA)
   ocv_cmake_configure("${CMAKE_CURRENT_LIST_DIR}/templates/OpenCVConfig-CUDA.cmake.in" CUDA_CONFIGCMAKE @ONLY)
 endif()
 
+if(HAVE_OPENMP)
+  ocv_cmake_configure("${CMAKE_CURRENT_LIST_DIR}/templates/OpenCVConfig-OPENMP.cmake.in" OPENMP_CONFIGCMAKE @ONLY)
+endif()
+
 if(ANDROID)
   if(NOT ANDROID_NATIVE_API_LEVEL)
     set(OpenCV_ANDROID_NATIVE_API_LEVEL_CONFIGCMAKE 0)
diff -Nuarp opencv-3.4.20.orig/cmake/templates/OpenCVConfig.cmake.in opencv-3.4.20/cmake/templates/OpenCVConfig.cmake.in
--- opencv-3.4.20.orig/cmake/templates/OpenCVConfig.cmake.in	2023-06-27 19:29:13.000000000 +0800
+++ opencv-3.4.20/cmake/templates/OpenCVConfig.cmake.in	2023-08-30 11:59:19.223817499 +0800
@@ -94,6 +94,7 @@ endif()
 
 
 @CUDA_CONFIGCMAKE@
+@OPENMP_CONFIGCMAKE@
 @ANDROID_CONFIGCMAKE@
 
 @IPPICV_CONFIGCMAKE@
diff -Nuarp opencv-3.4.20.orig/cmake/templates/OpenCVConfig-OPENMP.cmake.in opencv-3.4.20/cmake/templates/OpenCVConfig-OPENMP.cmake.in
--- opencv-3.4.20.orig/cmake/templates/OpenCVConfig-OPENMP.cmake.in	1970-01-01 08:00:00.000000000 +0800
+++ opencv-3.4.20/cmake/templates/OpenCVConfig-OPENMP.cmake.in	2023-08-30 11:58:12.298980226 +0800
@@ -0,0 +1,5 @@
+set(OpenCV_USE_OPENMP   "@HAVE_OPENMP@")
+
+if(OpenCV_USE_OPENMP)
+  find_package(OpenMP)
+endif()
diff -Nuarp opencv-3.4.20.orig/modules/core/CMakeLists.txt opencv-3.4.20/modules/core/CMakeLists.txt
--- opencv-3.4.20.orig/modules/core/CMakeLists.txt	2023-06-27 19:29:13.000000000 +0800
+++ opencv-3.4.20/modules/core/CMakeLists.txt	2023-08-30 12:13:56.534064133 +0800
@@ -113,6 +113,16 @@ ocv_target_link_libraries(${the_module}
     "${OPENCV_HAL_LINKER_LIBS}"
 )
 
+if(HAVE_OPENMP)
+  if(ANDROID_NDK_MAJOR AND (ANDROID_NDK_MAJOR GREATER 20))
+    ocv_target_link_libraries(${the_module} PUBLIC "-fopenmp" "-static-openmp")
+  elseif(OpenMP_CXX_FOUND)
+    ocv_target_link_libraries(${the_module} PUBLIC OpenMP::OpenMP_CXX)
+  else()
+    ocv_target_link_libraries(${the_module} PUBLIC "${OpenMP_CXX_FLAGS}")
+  endif()
+endif()
+
 if(OPENCV_CORE_EXCLUDE_C_API)
   ocv_target_compile_definitions(${the_module} PRIVATE "OPENCV_EXCLUDE_C_API=1")
 endif()