Question

我使用zbar扫描仪安卓，它很容易捕获条形码。但问题是，在具有自动对焦功能的手机上，它会过快地捕获条形码以便正确检测到它。如果它只能等待几毫秒，那么它就能够捕获更清晰的图像，从而不会显示“未找到”页面。

我该如何解决这个问题？有没有规定延迟对条形码的关注？也许延迟捕捉图像？

Answer 1

实施一个计数相似扫描结果的计数器。如果扫描结果保持不变（例如连续10次），我们可以假设结果非常可靠。

Answer 2

我非常喜欢@ Juuso_Ohtonen的回复，实际上只是在我自己的阅读器中使用它，但是如果你想要一个AutoFocus延迟，你可以创建一个Camera.AutoFocusCallback对象并用.postDelayed实现它的onAutoFocus方法。然后在您的Camera camera.autoFocus（）方法中使用此对象。

// Mimic continuous auto-focusing
Camera.AutoFocusCallback autoFocusCB = new Camera.AutoFocusCallback() {
    public void onAutoFocus(boolean success, Camera camera) {
        autoFocusHandler.postDelayed(doAutoFocus, 1000);
    }
};

此部分用于扩展SurfaceView的类，然后实现surfaceChanged（）;

public CameraPreview(Context context, Camera camera,
                      PreviewCallback previewCb,
                      AutoFocusCallback autoFocusCb) {
    super(context);
    mCamera = camera;
    previewCallback = previewCb;
    autoFocusCallback = autoFocusCb;

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);

    // deprecated setting, but required on Android versions prior to 3.0
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    /*
     * If your preview can change or rotate, take care of those events here.
     * Make sure to stop the preview before resizing or reformatting it.
     */
    if (mHolder.getSurface() == null) {
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e) {
        // ignore: tried to stop a non-existent preview
    }

    try {
        mCamera.setPreviewDisplay(mHolder);
        mCamera.setPreviewCallback(previewCallback);
        mCamera.startPreview();
        mCamera.autoFocus(autoFocusCallback);
    } catch (Exception e) {
        Log.d("DBG", "Error starting camera preview: " + e.getMessage());
    }
}

Zbar扫描仪和自动对焦

2 个答案: