OpenCvSharp

Cross platform wrapper of OpenCV for .NET Framework.

Old versions of OpenCvSharp is maintained in opencvsharp_2410.

Installation

NuGet

Search 'opencvsharp3' on the NuGet Package Manager.

Package	NuGet
All-in-one package - bundles native OpenCV DLLs
Minimum package
Development Build Package	https://ci.appveyor.com/nuget/opencvsharp

Downloads

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

Requirements

• OpenCV 4.0.0 with opencv_contrib
• (Windows)Visual C++ 2017 Redistributable Package
• .NET Framework 2.0 or later / .NET Core 2.0 / Mono

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

Documents

https://shimat.github.io/opencvsharp_docs/index.html

Usage

For more details, see the Wiki page.

// 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)) 
        {
            Cv2.WaitKey();
        }
    }
}

Features

• 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

Windows

• Install Visual Studio 2017 or later
  • VC++ features are required.
• Get all submodules

git submodule update --init --recursive

• Build tesseract and leptonica using vcpkg

.\vcpkg install tesseract:x64-windows-static
.\vcpkg install tesseract:x86-windows-static
.\vcpkg integrate install

• Build OpenCvSharp
  • Open OpenCvSharp.sln and build

Ubuntu 18.04

• Build OpenCV with opencv_contrib.
  • https://www.learnopencv.com/install-opencv-4-on-ubuntu-18-04/
• Install .NET Core SDK. https://dotnet.microsoft.com/download/linux-package-manager/ubuntu18-04/sdk-2.1.202
• Get OpenCvSharp source files

git clone https://github.com/shimat/opencvsharp.git
cd opencvsharp
git fetch --all --tags --prune && git checkout ${OPENCVSHARP_VERSION}

• Build native wrapper OpenCvSharpExtern

cd opencvsharp/src
mkdir build
cd build
cmake -D CMAKE_INSTALL_PREFIX=${YOUR_OPENCV_INSTALL_PATH} ..
make -j4 
make install

You should add reference to opencvsharp/src/build/OpenCvSharpExtern/libOpenCvSharpExtern.so

export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/home/shimat/opencvsharp/src/build/OpenCvSharpExtern"

• Add OpenCvSharp3-WithoutDll NuGet package to your project

dotnet new console ConsoleApp01
cd ConsoleApp01
dotnet add package OpenCvSharp3-WithoutDll
dotnet run

Older Ubuntu

Refer to the Dockerfile and Wiki pages.

License

Licensed under the BSD 3-Clause License.