Bug 431115

Yes, opencv is not compiled with CUDA support.

In fact plenty of features are disabled :

https://invent.kde.org/graphics/digikam/-/blob/master/project/bundles/3rdparty/ext_opencv/CMakeLists.txt#L11

Why ? because Opencv is a biggggg puzzle, very complex to stabilize and optimize (from the digiKam side implementations).

Gilles Caulier

Git commit 1e1a075f2cbb5160cff28f453a4a3693a97388df by Gilles Caulier.
Committed on 03/04/2023 at 12:45.
Pushed by cgilles into branch 'master'.

enable OpenCL compilation options in bundles.
OpenCL support still disabled by default

M  +9    -11   project/bundles/3rdparty/ext_opencv/CMakeLists.txt
D  +0    -12   project/bundles/3rdparty/ext_opencv/opencv-mmpause-linux.patch

https://invent.kde.org/graphics/digikam/commit/1e1a075f2cbb5160cff28f453a4a3693a97388df

diff --git a/project/bundles/3rdparty/ext_opencv/CMakeLists.txt b/project/bundles/3rdparty/ext_opencv/CMakeLists.txt
index 1371da72d6c..e8172314ccc 100644
--- a/project/bundles/3rdparty/ext_opencv/CMakeLists.txt
+++ b/project/bundles/3rdparty/ext_opencv/CMakeLists.txt
@@ -78,17 +78,18 @@ set(Opencv_Conf -DBUILD_EXAMPLES=OFF
                 -DWITH_IMGCODEC_HDR=OFF
                 -DWITH_IMGCODEC_SUNRASTER=OFF
                 -DWITH_IMGCODEC_PXM=OFF
+                -DCV_TRACE=OFF
+                -DCV_ENABLE_INTRINSICS=OFF
+                -DCV_DISABLE_OPTIMIZATION=ON
                 -DWITH_CUDA=OFF
                 -DWITH_CUFFT=OFF
                 -DWITH_CUBLAS=OFF
                 -DWITH_NVCUVID=OFF
-                -DWITH_OPENCL=OFF
-                -DWITH_OPENCL_SVM=OFF
-                -DWITH_OPENCLAMDFFT=OFF
-                -DWITH_OPENCLAMDBLAS=OFF
-                -DCV_ENABLE_INTRINSICS=OFF
-                -DCV_DISABLE_OPTIMIZATION=ON
-                -DCV_TRACE=OFF
+                -DWITH_OPENCL=ON
+                -DWITH_OPENCL_SVM=ON
+                -DWITH_OPENCLAMDFFT=ON
+                -DWITH_OPENCLAMDBLAS=ON
+                -DWITH_OPENCL_D3D11_NV=ON
 )

 JoinListAsString("${Opencv_Conf}" " " BASH_OPTIONS)
@@ -132,7 +133,7 @@ elseif(APPLE)
         ALWAYS 0
     )

-else() #Linux
+else() # Linux

     ExternalProject_Add(ext_opencv
         DOWNLOAD_DIR ${EXTERNALS_DOWNLOAD_DIR}
@@ -142,9 +143,6 @@ else() #Linux

         INSTALL_DIR ${EXTPREFIX_opencv}

-        # To fix broken compilation under Linux 32 bits
-        PATCH_COMMAND ${PATCH_COMMAND} -p1 -i ${CMAKE_CURRENT_SOURCE_DIR}/opencv-mmpause-linux.patch
-
         CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${EXTPREFIX_opencv}
                    -DCMAKE_BUILD_TYPE=${GLOBAL_BUILD_TYPE}
                    ${GLOBAL_PROFILE}
diff --git a/project/bundles/3rdparty/ext_opencv/opencv-mmpause-linux.patch b/project/bundles/3rdparty/ext_opencv/opencv-mmpause-linux.patch
deleted file mode 100644
index 7bda6d1d1aa..00000000000
--- a/project/bundles/3rdparty/ext_opencv/opencv-mmpause-linux.patch
+++ /dev/null
@@ -1,12 +0,0 @@
-diff --git a/modules/core/src/parallel_impl.cpp b/modules/core/src/parallel_impl.cpp
-index bc64fce7a..e80ebc3d1 100644
---- a/modules/core/src/parallel_impl.cpp
-+++ b/modules/core/src/parallel_impl.cpp
-@@ -44,6 +44,7 @@ DECLARE_CV_YIELD
- # endif
- #endif // CV_YIELD
-
-+#include <xmmintrin.h>
- // Spin lock's CPU-level yield (required for Hyper-Threading)
- #ifdef DECLARE_CV_PAUSE
- DECLARE_CV_PAUSE

Git commit 51cc28d4c44b8e70228da877dd59b6970986731f by Gilles Caulier.
Committed on 03/04/2023 at 15:31.
Pushed by cgilles into branch 'master'.

add OpenCV::OpenCL configuration in Components Info Dialog

M  +1    -0    core/app/utils/digikam_opencv.h.cmake.in
M  +189  -0    core/libs/dialogs/libsinfodlg.cpp
M  +8    -0    core/libs/dialogs/libsinfodlg.h

https://invent.kde.org/graphics/digikam/commit/51cc28d4c44b8e70228da877dd59b6970986731f

Git commit 9dce758cc0363a90ea1cc15ab06f34551e42d867 by Gilles Caulier.
Committed on 03/04/2023 at 16:04.
Pushed by cgilles into branch 'master'.

add OpenCV hardware and threads support information

M  +66   -12   core/libs/dialogs/libsinfodlg.cpp

https://invent.kde.org/graphics/digikam/commit/9dce758cc0363a90ea1cc15ab06f34551e42d867

Git commit aaac1dc16783211286501b782445601ffe2545a6 by Gilles Caulier.
Committed on 03/04/2023 at 16:22.
Pushed by cgilles into branch 'master'.

update online documentation about the OpenCV::OpenCL support option from the Setup/Miscs configuration panel.

M  +1    -1    menu_descriptions/menu_mainwindow.rst
M  +1    -1    setup_application/miscs_settings.rst

https://invent.kde.org/documentation/digikam-doc/commit/aaac1dc16783211286501b782445601ffe2545a6

The digiKam bundles (AppImage, Windows, MacOS) now have the OpenCV::OpenCL compilation enabled.
OpenCV::OpenCL support is disabled by default in application and needs to be turned on in Setup/Miscs/System configuration panel, for stability reasons.

Gilles Caulier

(In reply to caulier.gilles from comment #6)
> The digiKam bundles (AppImage, Windows, MacOS) now have the OpenCV::OpenCL
> compilation enabled.
> OpenCV::OpenCL support is disabled by default in application and needs to be
> turned on in Setup/Miscs/System configuration panel, for stability reasons.
> 
> Gilles Caulier

Are there plans for the linux release to get a release with OpenCL enabled?

(In reply to abstract.wolf@gmail.com from comment #7)
> (In reply to caulier.gilles from comment #6)
> > The digiKam bundles (AppImage, Windows, MacOS) now have the OpenCV::OpenCL
> > compilation enabled.
> > OpenCV::OpenCL support is disabled by default in application and needs to be
> > turned on in Setup/Miscs/System configuration panel, for stability reasons.
> > 
> > Gilles Caulier
> 
> Are there plans for the linux release to get a release with OpenCL enabled?

Ooops, I just saw that your comment didn't mention Linux, but in fact, after unchecking "Disable hardware acceleration OpenCL", my digikam is using OpenCL: http://ix.io/4vhU