capture images from webcam using c# with .net5

Question

I am trying to make a simple form to capture images from webCam, on my .net5 project however I could not seem to find a simple solution for this. I try AForge, OpenCVSharp.. they do not support .net5 yet I got a project to run but it turns out just blank (no webcam image). I google search and try almost everything I can found on my end.

I am wondering if anyone got any suggestions for a solution to this problem prefer opensource components

edit1: I am using Winforms for desktop applications.

Answer 1

OpenCvSharp4 supports .NET5 (and also .NET6 preview :-)).

How to reproduce

1. Create an empty "Windows Forms App" project form Visual Studio. (Obviously don't use .NET Framework...)

2. Add nuget package OpenCvSharp4.Windows. Below my csproj file.

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net5.0-windows7.0</TargetFramework>
    <Nullable>enable</Nullable>
    <UseWindowsForms>true</UseWindowsForms>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="OpenCvSharp4.Windows" Version="4.5.3.20210817" />
  </ItemGroup>

</Project>

3. Add a Button and a PictureBox to Form1 using designer.

4. Copy and paste code below in the Form1.cs.

using OpenCvSharp;
using OpenCvSharp.Extensions;
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;

namespace WebCam
{
    public partial class Form1 : Form
    {
        VideoCapture capture;
        Mat frame;
        Bitmap image;

        public Form1()
        {
            InitializeComponent();

            frame = new Mat();
            capture = new VideoCapture(0);
            capture.Open(0);
        }

        private void button1_Click(object sender, EventArgs e)
        {

            if (capture.IsOpened())
            {
                capture.Read(frame);
                image = BitmapConverter.ToBitmap(frame);
                if (pictureBox1.Image != null)
                {
                    pictureBox1.Image.Dispose();
                }
                pictureBox1.Image = image;
            }
        }
    }
}

That's all.