使用 ARKit 和 ZXing 在 Unity 中读取二维码

Question

我正在尝试使用以下库读取 QR 码：

• ARKit
• 志兴

然而，它似乎并不顺利。几个小时后，我仍然无法读出一个像样的二维码。 调试时我应用纹理来查看我的结果。由于纹理 Y，它看起来是红色的，但除此之外它还显示 QR 码。 解释纹理不会返回任何 ZXing 分析的数据。

这是我为此使用的以下代码：

#if UNITY_IOS && !UNITY_EDITOR
    // Update is called once per frame
    // BETTER: InvokeRepeating
    void Update()
    {
        if (!done) {
            ARTextureHandles handles = arSession.GetARVideoTextureHandles();
            //ARTextureHandles handles = UnityARSessionNativeInterface.GetARSessionNativeInterface().GetARVideoTextureHandles();
            if (handles.IsNull())
            {
                return;
            }
            if (handles.TextureY != System.IntPtr.Zero) {
                ReadQRCode (handles.TextureY);
            }
        }

}
#endif

private void ReadQRCode(System.IntPtr mtlTexPtr)
{
    Debug.Log("---------------");
    Debug.Log("Scanning...");

    Resolution currentResolution = Screen.currentResolution;

    tex = (UnityEngine.Texture2D)GameObject.Find("Camera").GetComponent<UnityARVideo>().m_ClearMaterial.GetTexture("_textureCbCr");

    tex.UpdateExternalTexture(mtlTexPtr);

    try
    {
        if(barCodeReader == null) {
            Debug.Log("Could not find barcorereader");
        }
        if(tex == null) {
            Debug.Log("Could not find texture");
        }

        var data = barCodeReader.Decode(tex.GetPixels32(), currentResolution.width, currentResolution.height);
        if (data != null)
        {
            Debug.Log("QR: " + data.Text);
        }
        else
        {
            Debug.Log("NO QR: " + "No QR code detected !");
        }
    }
    catch (Exception e)
    {
        Debug.LogError("Error reading QR");
        Debug.LogError(e.Message);
    }
}

Answer 1

经过进一步挖掘，我发现了一个与 OpenCV 类似的示例。

事实证明这对我很有效。

public class FrameCapturer : MonoBehaviour {

    // Script Inputs
    public bool m_shouldCaptureOnNextFrame = false;
    public Color32[] m_lastCapturedColors;

    // Privates
    Texture2D m_centerPixTex;

    void Start()
    {
        Resolution currentResolution = Screen.currentResolution;
        m_centerPixTex = new Texture2D(currentResolution.width, currentResolution.height, TextureFormat.RGBA32, false);
    }

    void OnPostRender()
    {

        if (m_shouldCaptureOnNextFrame)
        {
            Resolution res = Screen.currentResolution;
            m_lastCapturedColors = GetRenderedColors();
            m_shouldCaptureOnNextFrame = false;
        }
    }

    // Helpers
    Color32[] GetRenderedColors()
    {
        Resolution currentResolution = Screen.currentResolution;
        m_centerPixTex.ReadPixels(new Rect(0, 0, currentResolution.width, currentResolution.height), 0, 0);
        m_centerPixTex.Apply();

        return m_centerPixTex.GetPixels32();
    }
}

我将它附加到主摄像头，AR 脚本也附加在该主摄像头下。然后我是二维码阅读器，我可以简单地使用以下内容：

public class QRCodeReader : MonoBehaviour
{
    public Camera cam;
    private BarcodeReader barCodeReader;

    FrameCapturer m_pixelCapturer;

    // Use this for initialization
    void Start()
    {
        barCodeReader = new BarcodeReader();
        Resolution currentResolution = Screen.currentResolution;
        m_pixelCapturer = cam.GetComponent<FrameCapturer>();
    }

    void Update()
    {

        Resolution currentResolution = Screen.currentResolution;

        try
        {
            Color32[] framebuffer = m_pixelCapturer.m_lastCapturedColors;
            if (framebuffer.Length == 0)
            {
                return;
            }

            var data = barCodeReader.Decode(framebuffer, currentResolution.width, currentResolution.height);
            if (data != null)
            {
                // QRCode detected.
                Debug.Log(data);
                Debug.Log("QR: " + data.Text);

                //OnQrCodeRead(new QrCodeReadEventArgs() { text = data.Text });
            }

        }
        catch (Exception e)
        {
            Debug.LogError("Error reading QR");
            Debug.LogError(e.Message);
        }

        // skip 1 frame each time 
        // solves GetPixels() blocks for ReadPixels() to complete
        // https://medium.com/google-developers/real-time-image-capture-in-unity-458de1364a4c
        m_pixelCapturer.m_shouldCaptureOnNextFrame = true;

    }
}

我将此答案改编为的原始来源：https://github.com/realityenhanced/ARKitExperiments/blob/master/Assets/Scripts/CaptureCenterPixel.cs

Answer 2

我曾与 ZXing 和 ARkit 合作过，但从未合作过。

试图让一些工作至少给你一个关于可能发生的事情的提示。

作为 ARCameraManager 的子项，添加另一个（除了您的主 AR 摄像头）相机，并附加一个 ARVideo 脚本（删除诸如音频监听器、Flare 层和 guiLayer 之类的东西）另外添加以下脚本，它就在那里检索renderTexture：

[RequireComponent(typeof(Camera))]
public class WebcamFetcher : MonoBehaviour
{
private RenderTexture _vertical;
private RenderTexture _horizontal;
private Camera _camera;

// Update is called once per frame
public RenderTexture RenderTexture
{
    get
    {
        var orientation = Screen.orientation;
        if (orientation == ScreenOrientation.Landscape || orientation == ScreenOrientation.LandscapeLeft || orientation == ScreenOrientation.LandscapeRight)
        {
            return _horizontal;
        }
        else
        {
            return _vertical;
        }
    }
}

// Use this for initialization
void Start ()
{
    _camera = GetComponent<Camera>();
    _horizontal = new RenderTexture(Screen.width, Screen.height, 24);
    _vertical = new RenderTexture(Screen.height, Screen.width, 24);
}

// Update is called once per frame
void Update()
{
    var orientation = Screen.orientation;
    if (orientation == ScreenOrientation.Landscape || orientation == ScreenOrientation.LandscapeLeft || orientation == ScreenOrientation.LandscapeRight)
    {
        _camera.targetTexture = _horizontal;
    }
    else
    {
        _camera.targetTexture = _vertical;
    }
}

}

然后使用如下脚本：

private string DecodeQR(Color32[] pixels, int width, int height)
{
    try
    {
        IBarcodeReader barcodeReader = new BarcodeReader();

        // decode the current frame
        var result = barcodeReader.Decode(pixels, width, height);

        if (result != null)
        {
            return result.Text;
        }
    }
    catch (Exception ex) { Debug.LogError(ex.Message); }
    return null;
}

[SerializeField] Text QrDisplay; // A text field to display detected QRs to

public void OnQrDetect() // a callback for a UI button
{
    var texture = new Texture2D(_webcamFetcher.RenderTexture.width, _webcamFetcher.RenderTexture.height);
    RenderTexture.active = _webcamFetcher.RenderTexture;
    texture.ReadPixels(new Rect(Vector2.zero, new Vector2(_webcamFetcher.RenderTexture.width, _webcamFetcher.RenderTexture.height)), 0, 0);

    var qrText = DecodeQR(texture.GetPixels32(), _webcamFetcher.RenderTexture.width, _webcamFetcher.RenderTexture.height);
    if (qrText != null)
    {
        QrDisplay.text = qrText;
    }
}

为我工作。纹理检索可能不是最有效的。 但它有效 -> 这是可能的。