Unity Zxing QR code scanner integration

Question

I need to integrate Zxing with vuforia to make a QR code scanning app in Unity? I have no idea how to integrate Zxing with Vuforia in unity.Can someone guide me how to do this?I have Zxing .dll files and Vuforia unity package.Thanks in Advance.

Answer 1

I was looking for integrating Zxing with vuforia in Unity today.

The first thing to do is to download the dll from : https://zxingnet.codeplex.com/ and copy the unity dll into your Plugins folder (which should be in the Assets folder)

Then, I managed to found some examples (some of theses is outdated) :

• http://ydaira.blogspot.fr/2012/09/how-to-decode-qr-codes-using-unity3d.html

• https://github.com/Redth/ZXing.Net/blob/master/Clients/VuforiaDemo/Assets/VuforiaScanner.cs

After merging theses examples and simplify them, I got something like this (which is placed of the ARCamera prefab) :

using UnityEngine;
using System;
using System.Collections;

using Vuforia;

using System.Threading;

using ZXing;
using ZXing.QrCode;
using ZXing.Common;


[AddComponentMenu("System/VuforiaScanner")]
public class VuforiaScanner : MonoBehaviour
{    
    private bool cameraInitialized;

    private BarcodeReader barCodeReader;

    void Start()
    {        
        barCodeReader = new BarcodeReader();
        StartCoroutine(InitializeCamera());
    }

    private IEnumerator InitializeCamera()
    {
        // Waiting a little seem to avoid the Vuforia's crashes.
        yield return new WaitForSeconds(1.25f);

        var isFrameFormatSet = CameraDevice.Instance.SetFrameFormat(Image.PIXEL_FORMAT.RGB888, true);
        Debug.Log(String.Format("FormatSet : {0}", isFrameFormatSet));

        // Force autofocus.
        var isAutoFocus = CameraDevice.Instance.SetFocusMode(CameraDevice.FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
        if (!isAutoFocus)
        {
            CameraDevice.Instance.SetFocusMode(CameraDevice.FocusMode.FOCUS_MODE_NORMAL);
        }
        Debug.Log(String.Format("AutoFocus : {0}", isAutoFocus));
        cameraInitialized = true;
    }

    private void Update()
    {
        if (cameraInitialized)
        {
            try
            {
                var cameraFeed = CameraDevice.Instance.GetCameraImage(Image.PIXEL_FORMAT.RGB888);
                if (cameraFeed == null)
                {
                    return;
                }
                var data = barCodeReader.Decode(cameraFeed.Pixels, cameraFeed.BufferWidth, cameraFeed.BufferHeight, RGBLuminanceSource.BitmapFormat.RGB24);
                if (data != null)
                {
                    // QRCode detected.
                    Debug.Log(data.Text);
                }
                else
                {
                    Debug.Log("No QR code detected !");
                }
            }
            catch (Exception e)
            {
                Debug.LogError(e.Message);
            }
        }
    }    
}

I manage to make it works in an AVD (Android Virtual Device), so it will works on a real device.

Answer 2

If you have lags during scanning, this code should help you. I used KDelli's answer and used another thread for the code of decoding qr.

using UnityEngine;
using System;
using System.Collections;

using Vuforia;

using System.Threading;

using ZXing;
using ZXing.QrCode;
using ZXing.Common;


[AddComponentMenu("System/VuforiaCamera")]
public class VuforiaCamera : MonoBehaviour
{    
private bool cameraInitialized;

private BarcodeReader barCodeReader;
private bool isDecoding = false;

void Start()
{        
    barCodeReader = new BarcodeReader();
    StartCoroutine(InitializeCamera());
}

private IEnumerator InitializeCamera()
{
    // Waiting a little seem to avoid the Vuforia's crashes.
    yield return new WaitForSeconds(1.25f);

    // var isFrameFormatSet = CameraDevice.Instance.SetFrameFormat(Image.PIXEL_FORMAT.RGB888, true);
    // Debug.Log(String.Format("FormatSet : {0}", isFrameFormatSet));

    // Force autofocus.
    var isAutoFocus = CameraDevice.Instance.SetFocusMode(CameraDevice.FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
    if (!isAutoFocus)
    {
        CameraDevice.Instance.SetFocusMode(CameraDevice.FocusMode.FOCUS_MODE_NORMAL);
    }
    Debug.Log(String.Format("AutoFocus : {0}", isAutoFocus));
    cameraInitialized = true;
}

private void Update()
{
    if (cameraInitialized && !isDecoding)
    {
        try
        {
            var cameraFeed = CameraDevice.Instance.GetCameraImage(Image.PIXEL_FORMAT.RGB888);

            if (cameraFeed == null)
            {
                return;
            }
            ThreadPool.QueueUserWorkItem(new WaitCallback(DecodeQr), cameraFeed);

        }
        catch (Exception e)
        {
            Debug.LogError(e.Message);
        }
    }
}

private void DecodeQr(object state){
    isDecoding = true;
    var cameraFeed = (Image)state;
    var data = barCodeReader.Decode(cameraFeed.Pixels, cameraFeed.BufferWidth, cameraFeed.BufferHeight, RGBLuminanceSource.BitmapFormat.RGB24);
    if (data != null)
        {
        // QRCode detected.
            isDecoding = false;
        }
    else
        {
            isDecoding = false;
            Debug.Log("No QR code detected !");
        }
}    
}

Answer 3

If you use Unity 5.x and 64-bit Windows you may get an error

Failed to load Assets/Plugins/QCARWrapper.dll

Solution is simple as stated in the question Unity3d - Failed to load 'Assets/Plugins/QCARWrapper.dll'

1. To use Vuforia with Unity 64 bit, just move the QCARWrapper DLLs from /Plugins to /Plugins/x86. These are the DLLs:

2. Select the QCARWrapper.bundle in the Unity Project view (located under Assets > Plugins ), so that its settings are shown in the Unity Inspector Change the settings of QCARWrapper.bundle in the Unity inspector from Any Platform to Standalone + Editor.

Than it works like a charm.