OpenCvSharp5.GdipExtensions

OpenCvSharp

A cross-platform .NET wrapper for OpenCV, providing image processing and computer vision functionality. Its API is intentionally designed to stay as close as practical to the native OpenCV C++ API while using C# conventions such as typed enums, exceptions, and deterministic disposal.

See OpenCV C++, Python (cv2), and OpenCvSharp for the main API and data-model differences.

This is the OpenCvSharp5 family (OpenCV 5.x, .NET 8+). If you need .NET Framework, Unity, or another pre-.NET 8 runtime, use the OpenCvSharp4 family (OpenCV 4.13.0) instead.

🔄 Already using OpenCvSharp4? See the Migration Guide (4 → 5) on GitHub for target framework changes, package/namespace renames, and OpenCV 5 API changes.

Supported Platforms

Target OpenCV version: 5.0.x (with opencv_contrib)

Quick Start

Windows

dotnet add package OpenCvSharp5.Windows

Linux / Ubuntu

dotnet add package OpenCvSharp5
dotnet add package OpenCvSharp5.official.runtime.linux-x64

macOS

dotnet add package OpenCvSharp5
# Intel (x64):
dotnet add package OpenCvSharp5.runtime.osx.x64
# Apple Silicon (arm64):
dotnet add package OpenCvSharp5.runtime.osx.arm64

For more installation options, see Installation on GitHub.

Requirements

Windows

• (Windows Server only) Media Foundation:

  Install-WindowsFeature Server-Media-Foundation
  

Linux (Ubuntu and other distributions)

The official OpenCvSharp5.official.runtime.linux-x64 package is built on manylinux_2_28 (glibc 2.28) and works on Ubuntu 20.04+, Debian 10+, RHEL/AlmaLinux 8+, and other Linux distributions.

• Full package: uses GTK3 for highgui support (Cv2.ImShow, Cv2.WaitKey, etc.). GTK3 (libgtk-3.so.0) is pre-installed on standard Ubuntu/Debian/RHEL environments and typically requires no action. In minimal or container environments where GTK3 is absent, install it manually: Ubuntu/Debian: apt-get install libgtk-3-0; RHEL/AlmaLinux: dnf install gtk3. Alternatively, use the headless or slim package below, neither of which has GUI dependencies.
• Headless package (OpenCvSharp5.official.runtime.linux-x64.headless): same module set as full (videoio, dnn, ml, contrib, stitching, barcode, ...) but highgui is disabled, so it has no GTK3/X11 dependency. Suitable for containerized services that need more than the slim module set (e.g. VideoCapture) but never call highgui.
• Slim package (OpenCvSharp5.official.runtime.linux-x64.slim): highgui is disabled and the module set is reduced; no GTK3 or other GUI dependencies. Suitable for headless and container environments.

macOS (Intel and Apple Silicon)

The OpenCvSharp5.runtime.osx.x64 and OpenCvSharp5.runtime.osx.arm64 packages provide native bindings for macOS. FFmpeg, Tesseract, Freetype, and all standard OpenCV modules are statically linked.

Slim Profile

The slim runtime packages (OpenCvSharp5.Windows.Slim, OpenCvSharp5.official.runtime.linux-x64.slim, etc.) bundle a smaller native library:

Usage

Always release Mat and other IDisposable resources using the using statement:

using OpenCvSharp;

// Edge detection using Canny algorithm
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();
}

Mat arithmetic operators (+, -, *, /, comparisons, bitwise, T(), Inv(), ...) return a lazily-evaluated managed expression tree that holds no unmanaged resources, so chained expressions never leak. Just receive the result in a using Mat:

using var src = new Mat("lenna.png", ImreadModes.Grayscale);

// The intermediate (src * 0.8) holds no native resource; nothing leaks.
using Mat dst = 255 - src * 0.8;

Note: OpenCvSharp does not support Unity, Xamarin, CUDA or UWP.

Resources

• GitHub Repository
• Code Samples
• Documentation and API Reference
• Issue Tracker