1. Background

C# (C Sharp) is a development language on windows. Its advantage is that it is relatively simple and quick to develop window programs.

OpenCV is a commonly used image processing library, but officially supports C++ and Python.

OpenCvSharp is a library that enables OpenCV to support C# development. Based on Visual Studio development.

Follow this article to create an OpenCvSharp hello world.

2. Environment

Win10 + Visual Studio 2019 + OpenCvSharp4

3. Prepare Visual Studio 2019

The download page is https://visualstudio.microsoft.com/vs/ . Community edition, you can use it for free after registering. In addition, we need to use VIsual Studio Installer to install "Universal Windows Platform Development" so that we can use C# to develop desktop programs.

4. Install (Windows) Visual C++ 2019 Redistributable Package

This is because the official statement [1] requires this runtime package.

5. Hello world

5.1 Create a new project and enter the project name.

5.2 Add OpenCvSharp dll to the project

Tools -> NuGet Package Manager -> NuGet Packages for Management Solutions -> Install OpenCvSharp4 and OpenCvSharp4.runtime.win respectively

5.3 Add core code

5.3.1 Double click anywhere in the red box

After double-clicking, the code window will appear.

Type above:

using OpenCvSharp;

In the Form1_Load() function, enter the code

All codes:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using OpenCvSharp;

namespace OpenCVSharp_Test1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Mat src = new Mat("C:\\Users\\qjfen\\Pictures\\Lenna-Kuurmaa-vanilla-ninja-13314479-1024-768.jpg", 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();
            }
        }
    }
}

6 Compile the project and run

6.1 Shortcut keys to compile the project shift + ctrl + B

6.2 Operation

Reference address:

1. OpenCvSharp official github repository, https://github.com/shimat/opencvsharp

A preliminary study on OpenCvSharp4