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    Windows Armpl Opencv

    Windows Armpl Opencv

    Building OpenCV with ARM Performance Libraries (ARMPL) on Windows {#tutorial_windows_armpl}

    @prev_tutorial{tutorial_windows_install} @next_tutorial{tutorial_linux_install}

    @tableofcontents

    Introduction {#tutorial_windows_armpl_intro}

    This tutorial explains how to build OpenCV on Windows (AArch64) with ARM Performance Libraries (ARMPL) as a math backend. ARMPL provides optimized BLAS and LAPACK routines for Arm-based hardware and can significantly accelerate OpenCV operations such as DFT and DCT.

    Step 1: Download and Install ARM Performance Libraries {#tutorial_windows_armpl_download}

    1. Open a browser and go to the ARM Performance Libraries Downloads page.

    2. Under Windows / AArch64, download the installer for your preferred toolchain:

      File Architecture Size
      arm-performance-libraries_26.01_Windows.msi AArch64 ~240 MiB

    3. Run the downloaded .msi installer and follow the on-screen instructions. The default installation directory is:

      C:\Program Files\Arm Performance Libraries\armpl_26.01

    Step 2: Configure System Environment Variables {#tutorial_windows_armpl_env}

    OpenCV's CMake scripts (and the ARMPL runtime itself) need to find the library files at both build time and run time. Add the following entries to the System PATH variable:

    1. Open System Properties, click Advanced, then Environment Variables.

    2. Under System variables, select Path and click Edit.

    3. Add the two paths below (adjust the version number if yours differs):

      C:\Program Files\Arm Performance Libraries\armpl_26.01\lib
C:\Program Files\Arm Performance Libraries\armpl_26.01\bin

    4. Click OK on every dialog to save.

    Step 3: Clone OpenCV {#tutorial_windows_armpl_clone}

    git clone https://github.com/opencv/opencv.git
cd opencv

    If you also need the extra modules:

    git clone https://github.com/opencv/opencv_contrib.git

    Step 4: Configure with CMake {#tutorial_windows_armpl_cmake}

    Create a build directory and run CMake with ARMPL support enabled.

    Without OpenMP (single-threaded ARMPL):

    mkdir build && cd build

cmake -G "Visual Studio 17 2022" -A ARM64 ^
      -DWITH_ARMPL=ON ^
      -DARMPL_ROOT_DIR="C:\Program Files\Arm Performance Libraries\armpl_26.01" ^
      -DWITH_OPENMP=OFF ^
      ..

    With OpenMP (multi-threaded ARMPL):

    ARMPL ships both serial and OpenMP-enabled library variants. To use the multi-threaded variant, enable OpenMP in CMake:

    mkdir build && cd build

cmake -G "Visual Studio 17 2022" -A ARM64 ^
      -DWITH_ARMPL=ON ^
      -DARMPL_ROOT_DIR="C:\Program Files\Arm Performance Libraries\armpl_26.01" ^
      -DWITH_OPENMP=ON ^
      ..

    @note Enabling WITH_OPENMP=ON causes CMake to link against the armpl_lp64_mp (multi-threaded) variant of ARMPL. Disabling it links against the serial armpl_lp64 variant. Only one variant should be enabled at a time to avoid symbol conflicts.

    Step 5: Build and Install {#tutorial_windows_armpl_build}

    Open the generated .sln file in Visual Studio and build the Release configuration, or build from the command line:

    cmake --build . --config Release --parallel
cmake --install . --config Release

    Step 6: Verify the Build {#tutorial_windows_armpl_verify}

    After a successful build, confirm that OpenCV detects ARMPL by running:

    opencv_version --verbose 2>&1 | findstr /i armpl

    You should see a line similar to:

      ARMPL:                       YES (armpl_26.01)

    Alternatively, check the CMake configuration log for the line:

    --   ARMPL support:             YES

    Troubleshooting {#tutorial_windows_armpl_troubleshoot}

    CMake cannot find ARMPL:

    Make sure ARMPL_ROOT_DIR points to the folder that contains both include\ and lib\ sub-directories:

    C:\Program Files\Arm Performance Libraries\armpl_26.01
    bin\
    include\
    lib\

    Runtime error: DLL not found:

    Ensure that both the lib\ and bin\ directories are on the system PATH and that you opened a new Command Prompt after adding them (changes are not picked up by already-open sessions).

    Linker errors with OpenMP:

    If you see duplicate symbol errors when WITH_OPENMP=ON, make sure you are not also linking against the serial ARMPL library. Pass -DWITH_OPENMP=ON consistently and clean the build directory before re-running CMake.

    See also {#tutorial_windows_armpl_seealso}