georgeemr / capture-vision-maui

.NET MAUI Camera View with Dynamsoft Vision SDKs

The project's goal is to assist developers in creating .NET MAUI applications featuring a custom camera view. It utilizes Dynamsoft Vision SDKs for barcode, MRZ (Machine Readable Zone), and document detection.

Example

https://github.com/yushulx/Capture-Vision-Maui/tree/main/Capture.Vision.Maui.Example

• Windows

  

• iOS

  

Demo Video: .NET MAUI QR Code Scanner

• Windows

  dotnet-maui-windows-qr-code-scanner.mp4

• Android

  dotnet-maui-android-qr-code-scanner.mp4

Supported Platforms

• Android
• iOS
• Windows

Features

• Read 1D barcodes, QR codes, PDF417, DataMatrix, and other formats from camera frames.
• Recognize Machine Readable Zones (MRZ) from camera frames.
• Detect document edges within camera frames.

Getting Started

1. Enable the camera view in MauiProgram.cs:

   builder.UseNativeCameraView()

2. Request a free trial license and replace LICENSE-KEY with your own license key in the platform-specific code.

   App.xaml.cs for Windows:

   using Dynamsoft;
   using Microsoft.UI.Xaml;
   namespace Capture.Vision.Maui.Example.WinUI
   {
       public partial class App : MauiWinUIApplication
       {
           public App()
           {
               this.InitializeComponent();
               BarcodeQRCodeReader.InitLicense("LICENSE-KEY");
               DocumentScanner.InitLicense("LICENSE-KEY");
               MrzScanner.InitLicense("LICENSE-KEY");
           }
       }
   }

   MainActivity.cs for Android:

   using Android.App;
   using Android.Content.PM;
   using Android.OS;
   using Dynamsoft;
   
   namespace Capture.Vision.Maui.Example
   {
       public class MainActivity : MauiAppCompatActivity
       {
           protected override void OnCreate(Bundle savedInstanceState)
           {
               base.OnCreate(savedInstanceState);
   
               // Your platform-specific code here
               BarcodeQRCodeReader.InitLicense("LICENSE-KEY");
               DocumentScanner.InitLicense("LICENSE-KEY");
               MrzScanner.InitLicense("LICENSE-KEY");
           }
       }
   }

   Program.cs for iOS:

   using ObjCRuntime;
   using UIKit;
   using Dynamsoft;
   
   static void Main(string[] args)
   {
       DocumentScanner.InitLicense("LICENSE-KEY");
       BarcodeQRCodeReader.InitLicense("LICENSE-KEY");
       MrzScanner.InitLicense("LICENSE-KEY");
   
       UIApplication.Main(args, null, typeof(AppDelegate));
   }

3. Create a content page to add the camera view:

   <?xml version="1.0" encoding="utf-8" ?>
   <ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
               xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
               xmlns:skia="clr-namespace:SkiaSharp.Views.Maui.Controls;assembly=SkiaSharp.Views.Maui.Controls"
               xmlns:cv="clr-namespace:Capture.Vision.Maui;assembly=Capture.Vision.Maui"
               x:Class="Capture.Vision.Maui.Example.CameraPage"
               Title="CameraPage">
       <ScrollView>
           <Grid>
               <cv:CameraView x:Name="cameraView" HorizontalOptions="FillAndExpand"
               VerticalOptions="FillAndExpand" EnableBarcode="True" EnableDocumentDetect="True" EnableMrz="True"
                                   ResultReady="cameraView_ResultReady" FrameReady="cameraView_FrameReady"
                               />
               <skia:SKCanvasView x:Name="canvasView" 
                           Margin="0"
                           HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"
                           PaintSurface="OnCanvasViewPaintSurface" />
           </Grid>
       </ScrollView>
   </ContentPage>

   Set EnableBarcode, EnableDocumentDetect, and EnableMrz to activate barcode, document, and MRZ (Machine Readable Zone) detection, respectively. Use the cameraView_ResultReady event to retrieve the results.

   private void cameraView_ResultReady(object sender, ResultReadyEventArgs e)
   {
       if (e.Result is BarcodeResult[])
       {}
       else if (e.Result is DocumentResult)
       {}
       else if (e.Result is MrzResult)
       {}    
   }

Custom Image Processing

In the cameraView_FrameReady event, you can access the camera frame for custom image processing.

private void cameraView_FrameReady(object sender, FrameReadyEventArgs e)
{
    // process image
}

The FrameReadyEventArgs provide the image buffer, width, height, stride and format.

public class FrameReadyEventArgs : EventArgs
{ 
    public enum PixelFormat
    {
        GRAYSCALE,
        RGB888,
        BGR888,
        RGBA8888,
        BGRA8888,
    }
    public FrameReadyEventArgs(byte[] buffer, int width, int height, int stride, PixelFormat pixelFormat)
    {
        Buffer = buffer;
        Width = width;
        Height = height;
        Stride = stride;
        Format = pixelFormat;
    }

    public byte[] Buffer { get; private set; }
    public int Width { get; private set; }
    public int Height { get; private set; }
    public int Stride { get; private set; }
    public PixelFormat Format { get; private set; }
}

Currently, frames captured from Windows and Android devices are in the GRAYSCALE format, whereas frames from iOS devices use the BGRA8888 format.

Barcode Parameters Configuration

Configure the barcode detection parameters to suit specific scenarios and requirements. This includes adjusting settings for barcode types, scanning precision, and other relevant factors.

public CameraPage()
{
    InitializeComponent();
    ...
    // cameraView.BarcodeParameters = "{\"Version\":\"3.0\", \"ImageParameter\":{\"Name\":\"IP1\", \"BarcodeFormatIds\":[\"BF_QR_CODE\", \"BF_ONED\"], \"ExpectedBarcodesCount\":20}}";
}

References

• Camera: https://github.com/hjam40/Camera.MAUI
• Barcode: https://github.com/yushulx/dotnet-barcode-qr-code-sdk
• Capture Vision: https://github.com/yushulx/Capture-Vision

Building NuGet Package from Source Code

cd Capture.Vision.Maui
dotnet build --configuration Release