Merge pull request #21329 from alalek:cmake_openexr_find_package

CMakeLists.txt

@@ -224,7 +224,7 @@ OCV_OPTION(BUILD_TIFF               "Build libtiff from source"          (WIN32
 OCV_OPTION(BUILD_JASPER             "Build libjasper from source"        (WIN32 OR ANDROID OR APPLE OR OPENCV_FORCE_3RDPARTY_BUILD) )
 OCV_OPTION(BUILD_JPEG               "Build libjpeg from source"          (WIN32 OR ANDROID OR APPLE OR OPENCV_FORCE_3RDPARTY_BUILD) )
 OCV_OPTION(BUILD_PNG                "Build libpng from source"           (WIN32 OR ANDROID OR APPLE OR OPENCV_FORCE_3RDPARTY_BUILD) )
-OCV_OPTION(BUILD_OPENEXR            "Build openexr from source"          (((WIN32 OR ANDROID OR APPLE) AND NOT WINRT) OR OPENCV_FORCE_3RDPARTY_BUILD) )
+OCV_OPTION(BUILD_OPENEXR            "Build openexr from source"          (OPENCV_FORCE_3RDPARTY_BUILD) )
 OCV_OPTION(BUILD_WEBP               "Build WebP from source"             (((WIN32 OR ANDROID OR APPLE) AND NOT WINRT) OR OPENCV_FORCE_3RDPARTY_BUILD) )
 OCV_OPTION(BUILD_TBB                "Download and build TBB from source" (ANDROID OR OPENCV_FORCE_3RDPARTY_BUILD) )
 OCV_OPTION(BUILD_IPP_IW             "Build IPP IW from source"           (NOT MINGW OR OPENCV_FORCE_3RDPARTY_BUILD) IF (X86_64 OR X86) AND NOT WINRT )
@@ -306,7 +306,7 @@ OCV_OPTION(WITH_JPEG "Include JPEG support" ON
 OCV_OPTION(WITH_WEBP "Include WebP support" ON
   VISIBLE_IF NOT WINRT
   VERIFY HAVE_WEBP)
-OCV_OPTION(WITH_OPENEXR "Include ILM support via OpenEXR" BUILD_OPENEXR OR NOT CMAKE_CROSSCOMPILING
+OCV_OPTION(WITH_OPENEXR "Include ILM support via OpenEXR" ((WIN32 OR ANDROID OR APPLE) OR BUILD_OPENEXR) OR NOT CMAKE_CROSSCOMPILING
   VISIBLE_IF NOT APPLE_FRAMEWORK AND NOT WINRT
   VERIFY HAVE_OPENEXR)
 OCV_OPTION(WITH_OPENGL "Include OpenGL support" OFF

cmake/OpenCVFindLibsGrfmt.cmake

@@ -242,6 +242,7 @@ if(WITH_OPENEXR)
     if(OPENEXR_VERSION)  # check via TARGET doesn't work
       set(BUILD_OPENEXR ON)
       set(HAVE_OPENEXR YES)
+      set(BUILD_OPENEXR ON)
     endif()
   endif()
 endif()

cmake/OpenCVFindOpenEXR.cmake

@@ -9,6 +9,27 @@
 # OPENEXR_LIBRARIES = libraries that are needed to use OpenEXR.
 #
 
+if(NOT HAVE_CXX11)
+  message(STATUS "OpenEXR: enable C++11 to use external OpenEXR")
+  return()
+endif()
+
+if(NOT OPENCV_SKIP_OPENEXR_FIND_PACKAGE)
+  find_package(OpenEXR 3 QUIET)
+  #ocv_cmake_dump_vars(EXR)
+  if(OpenEXR_FOUND)
+    if(TARGET OpenEXR::OpenEXR)  # OpenEXR 3+
+      set(OPENEXR_LIBRARIES OpenEXR::OpenEXR)
+      set(OPENEXR_INCLUDE_PATHS "")
+      set(OPENEXR_VERSION "${OpenEXR_VERSION}")
+      set(OPENEXR_FOUND 1)
+      return()
+    else()
+      message(STATUS "Unsupported find_package(OpenEXR) - missing OpenEXR::OpenEXR target (version ${OpenEXR_VERSION})")
+    endif()
+  endif()
+endif()
+
 SET(OPENEXR_LIBRARIES "")
 SET(OPENEXR_LIBSEARCH_SUFFIXES "")
 file(TO_CMAKE_PATH "$ENV{ProgramFiles}" ProgramFiles_ENV_PATH)

modules/imgcodecs/src/grfmt_exr.hpp

@@ -53,6 +53,7 @@
 #include <ImfInputFile.h>
 #include <ImfChannelList.h>
 #include <ImathBox.h>
+#include <ImfRgbaFile.h>
 #include "grfmt_base.hpp"
 
 namespace cv