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.NET Framework wrapper for OpenCV
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OpenCvSharp Build status GitHub license

Cross platform wrapper of OpenCV for .NET Framework.

Old versions of OpenCvSharp are maintained in opencvsharp_2410.



Package Description Link
OpenCvSharp4 OpenCvSharp core libraries NuGet version
OpenCvSharp4.Windows All-in-one package for Windows - same as OpenCvSharp3-AnyCPU NuGet version Native bindings for Windows x64/x86 NuGet version
OpenCvSharp4.runtime.ubuntu.18.04-x64 Native bindings for Ubuntu 18.04 x64 NuGet version
(beta packages) Development Build Package

Native binding (OpenCvSharpExtern.dll / is required to work OpenCvSharp. To use OpenCvSharp, you should add both OpenCvSharp4 and OpenCvSharp4.runtime.* packages to your project. Currently, native bindings for Windows and Ubuntu 18.04 are released.

Packages named OpenCvSharp3-* and OpenCvSharp-* are deprecated.


Add OpenCvSharp4 and NuGet packages to your project. You can use OpenCvSharp4.Windows instead.

Ubuntu 18.04

Add OpenCvSharp4 and OpenCvSharp4.runtime.ubuntu.18.04.x64 NuGet packages to your project

dotnet new console -n ConsoleApp01
cd ConsoleApp01
dotnet add package OpenCvSharp4
dotnet add package OpenCvSharp4.runtime.ubuntu.18.04-x64
# -- edit Program.cs --- # 
dotnet run


If you do not use NuGet, get DLL files from the release page.


OpenCvSharp may not work on UWP and Unity platform. Please consider using OpenCV for Unity



For more details, see samples and Wiki pages.

// Edge detection by Canny algorithm
using OpenCvSharp;

class Program 
    static void Main() 
        Mat src = new Mat("lenna.png", ImreadModes.Grayscale);
        // Mat src = Cv2.ImRead("lenna.png", ImreadModes.Grayscale);
        Mat dst = new Mat();
        Cv2.Canny(src, dst, 50, 200);
        using (new Window("src image", src)) 
        using (new Window("dst image", dst)) 


  • OpenCvSharp is modeled on the native OpenCV C/C++ API style as much as possible.
  • Many classes of OpenCvSharp implement IDisposable. There is no need to manage unsafe resources.
  • OpenCvSharp does not force object-oriented programming style on you. You can also call native-style OpenCV functions.
  • OpenCvSharp provides functions for converting from Mat/IplImage into Bitmap(GDI+) or WriteableBitmap(WPF).
  • OpenCvSharp can work on Mono. It can run on any platform which Mono supports (e.g. Linux).

OpenCvSharp Build Instructions


  • Install Visual Studio 2017 or later
    • VC++ features are required.
  • Get all submodules
git submodule update --init --recursive
  • Build OpenCvSharp
    • Open OpenCvSharp.sln and build

Ubuntu 18.04

git clone
cd opencvsharp
git fetch --all --tags --prune && git checkout ${OPENCVSHARP_VERSION}
  • Build native wrapper OpenCvSharpExtern
cd opencvsharp/src
mkdir build
cd build
make -j 
make install

You should add reference to opencvsharp/src/build/OpenCvSharpExtern/

export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/home/shimat/opencvsharp/src/build/OpenCvSharpExtern"
  • Add OpenCvSharp4 NuGet package to your project
dotnet new console -n ConsoleApp01
cd ConsoleApp01
dotnet add package OpenCvSharp4
# -- edit Program.cs --- # 
dotnet run

Older Ubuntu

Refer to the Dockerfile and Wiki pages.


Licensed under the BSD 3-Clause License.


If you find the OpenCvSharp library useful and would like to show your gratitude by donating, here are some donation options. Thank you.

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