base on OpenCV wrapper for .NET  [](https://github.com/shimat/opencvsharp/actions) [](https://github.com/shimat/opencvsharp/actions) [](https://github.com/shimat/opencvsharp/blob/master/LICENSE) Old versions of OpenCvSharp are stored in [opencvsharp_2410](https://github.com/shimat/opencvsharp_2410). ## NuGet ### Managed libraries | Package | Description | Link | |---------|-------------|------| |**OpenCvSharp4**| OpenCvSharp core libraries | [](https://badge.fury.io/nu/OpenCvSharp4) | |**OpenCvSharp4.Extensions**| GDI+ Extensions | [](https://badge.fury.io/nu/OpenCvSharp4.Extensions) | |**OpenCvSharp4.WpfExtensions**| WPF Extensions | [](https://badge.fury.io/nu/OpenCvSharp4.WpfExtensions) | |**OpenCvSharp4.Windows**| All-in-one package for Windows (except UWP) | [](https://badge.fury.io/nu/OpenCvSharp4.Windows) | ### Native bindings | Package | Description | Link | |---------|-------------|------| |**OpenCvSharp4.runtime.win**| Native bindings for Windows x64/x86 (except UWP) | [](https://badge.fury.io/nu/OpenCvSharp4.runtime.win) | |**OpenCvSharp4.runtime.uwp**| Native bindings for UWP (Universal Windows Platform) x64/x86/ARM | [](https://badge.fury.io/nu/OpenCvSharp4.runtime.uwp) | |**OpenCvSharp4.official.runtime.linux-x64**| Native bindings for Linux x64 | [](https://badge.fury.io/nu/OpenCvSharp4.official.runtime.linux-x64) | |**OpenCvSharp4.runtime.linux-arm**| Native bindings for Linux Arm | [](https://www.nuget.org/packages/OpenCvSharp4.runtime.linux-arm/) | |**OpenCvSharp4.runtime.wasm**| Native bindings for WebAssembly | [](https://www.nuget.org/packages/OpenCvSharp4.runtime.wasm/) | Native binding (OpenCvSharpExtern.dll / libOpenCvSharpExtern.so) 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, UWP and Ubuntu are released. Packages named OpenCvSharp3-* and OpenCvSharp-* are deprecated. > [OpenCvSharp3-AnyCPU](https://www.nuget.org/packages/OpenCvSharp3-AnyCPU/) / [OpenCvSharp3-WithoutDll](https://www.nuget.org/packages/OpenCvSharp3-WithoutDll/) / [OpenCvSharp-AnyCPU](https://www.nuget.org/packages/OpenCvSharp-AnyCPU/) / [OpenCvSharp-WithoutDll](https://www.nuget.org/packages/OpenCvSharp-WithoutDll/) ## Docker images https://github.com/shimat?tab=packages ## Installation ### Windows (except UWP) Add `OpenCvSharp4` and `OpenCvSharp4.runtime.win` NuGet packages to your project. You can use `OpenCvSharp4.Windows` instead. ### UWP Add `OpenCvSharp4` and `OpenCvSharp4.runtime.uwp` NuGet packages to your project. Note that `OpenCvSharp4.runtime.win` and `OpenCvSharp4.Windows` don't work for UWP. ### Ubuntu 22.04 Add `OpenCvSharp4` and `OpenCvSharp4.runtime.ubuntu.22.04.x64` NuGet packages to your project. ``` dotnet new console -n ConsoleApp01 cd ConsoleApp01 dotnet add package OpenCvSharp4 dotnet add package OpenCvSharp4_.runtime.ubuntu.22.04-x64 # -- edit Program.cs --- # dotnet run ``` ### Downloads If you do not use NuGet, get DLL files from the [release page](https://github.com/shimat/opencvsharp/releases). ## Target OpenCV * [OpenCV 4.10.0](http://opencv.org/) with [opencv_contrib](https://github.com/opencv/opencv_contrib) ## Requirements * [.NET Framework 4.8](http://www.microsoft.com/ja-jp/download/details.aspx?id=1639) / [.NET 6](https://www.microsoft.com/net/download) / .NET Standard 2.0 * (Windows) [Visual C++ 2022 Redistributable Package](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads) * (Windows Server) Media Foundation ``` PS1> Install-WindowsFeature Server-Media-Foundation ``` * (Ubuntu) You must pre-install all the dependency packages needed to build OpenCV. Many packages such as libjpeg must be installed in order to work OpenCV. https://www.learnopencv.com/install-opencv-4-on-ubuntu-18-04/ **OpenCvSharp won't work on Unity and Xamarin platform.** For Unity, please consider using [OpenCV for Unity](https://assetstore.unity.com/packages/tools/integration/opencv-for-unity-21088) or some other solutions. **OpenCvSharp does not support CUDA.** If you want to use the CUDA features, you need to customize the native bindings yourself. ## Usage For more details, see **[samples](https://github.com/shimat/opencvsharp_samples/)** and **[Wiki](https://github.com/shimat/opencvsharp/wiki)** pages. **Always remember to release Mat instances! The `using` syntax is useful.** ```C# // C# 8 // Edge detection by Canny algorithm using OpenCvSharp; class Program { static void Main() { using var src = new Mat("lenna.png", ImreadModes.Grayscale);        using var dst = new Mat(); Cv2.Canny(src, dst, 50, 200); using (new Window("src image", src)) using (new Window("dst image", dst)) { Cv2.WaitKey(); } } } ``` As mentioned above, objects of classes, such as Mat and MatExpr, have unmanaged resources and need to be manually released by calling the Dispose() method. Worst of all, the +, -, *, and other operators create new objects each time, and these objects need to be disposed, or there will be memory leaks. Despite having the using syntax, the code still looks very verbose. Therefore, a ResourcesTracker class is provided. The ResourcesTracker implements the IDisposable interface, and when the Dispose() method is called, all resources tracked by the ResourcesTracker are disposed. The T() method of ResourcesTracker can trace an object or an array of objects, and the method NewMat() is like T(new Mat(...). All the objects that need to be released can be wrapped with T().For example: t.T(255 - t.T(picMat * 0.8)) . Example code is as following: ```csharp using (var t = new ResourcesTracker()) { Mat mat1 = t.NewMat(new Size(100, 100), MatType.CV_8UC3, new Scalar(0)); Mat mat3 = t.T(255-t.T(mat1*0.8)); Mat[] mats1 = t.T(mat3.Split()); Mat mat4 = t.NewMat(); Cv2.Merge(new Mat[] { mats1[0], mats1[1], mats1[2] }, mat4); } using (var t = new ResourcesTracker()) { var src = t.T(new Mat(@"lenna.png", ImreadModes.Grayscale)); var dst = t.NewMat(); Cv2.Canny(src, dst, 50, 200); var blurredDst = t.T(dst.Blur(new Size(3, 3))); t.T(new Window("src image", src)); t.T(new Window("dst image", blurredDst)); 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` into `Bitmap`(GDI+) or `WriteableBitmap`(WPF). ## Code samples https://github.com/shimat/opencvsharp_samples/ ## API Documents http://shimat.github.io/opencvsharp/api/OpenCvSharp.html ## OpenCvSharp Build Instructions ### Windows - Install Visual Studio 2022 or later - VC++ features are required. - Run `download_opencv_windows.ps1` to download OpenCV libs and headers from https://github.com/shimat/opencv_files. Those lib files are precompiled by the owner of OpenCvSharp using GitHub Actions. ``` .\download_opencv_windows.ps1 ``` - Build OpenCvSharp - Open `OpenCvSharp.sln` and build #### How to customize OpenCV binaries yourself If you want to use some OpenCV features that are not provided by default in OpenCvSharp (e.g. GPU), you will have to build OpenCV yourself. The binary files of OpenCV for OpenCvSharp for Windows are created in the [opencv_files](https://github.com/shimat/opencv_files) repository. See the README. - `git clone --recursive https://github.com/shimat/opencv_files` - Edit `build_windows.ps1` or `build_uwp.ps1` to customize the CMake parameters . - Run the PowerShell script. ### Ubuntu - Build OpenCV with opencv_contrib. - https://www.learnopencv.com/install-opencv-4-on-ubuntu-18-04/ - Install .NET Core SDK. https://learn.microsoft.com/ja-jp/dotnet/core/install/linux-ubuntu - 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 -j 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 `OpenCvSharp4` NuGet package to your project ``` dotnet new console -n ConsoleApp01 cd ConsoleApp01 dotnet add package OpenCvSharp4 # -- edit Program.cs --- # dotnet run ``` ## Donations If you find the OpenCvSharp library useful and would like to show your gratitude by donating, here are some donation options. Thank you. https://github.com/sponsors/shimat ", Assign "at most 3 tags" to the expected json: {"id":"6886","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"