大家好，我对Google移动视觉API尤其是数据矩阵格式有疑问。
我几乎可以扫描每种条形码格式，但是当我要扫描数据矩阵时，事情变得越来越难了。我只能检测出十分之一的人，这很尴尬。
我遵循了文档，并添加了如下遵循的检测格式：
一维条形码：EAN-13，EAN-8，UPC-A，UPC-E，Code-39，Code-93，Code-128，ITF，Codabar
二维条形码：QR码，数据矩阵，PDF-417，AZTEC
我的活动看起来像这样（继续：Google vision Android Github）
public class QrScanActivity extends AppCompatActivity implements BarcodeTracker.BarcodeTrackerListener {
private static final String TAG = QrScanActivity.class.getSimpleName();
// permission request codes need to be < 256
private static final int RC_HANDLE_CAMERA_PERM = 2;
public static final String BARCODE_OBJECT = "Barcode";
private CameraSource _cameraSource;
private CameraSourcePreview _preview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_qrscan);
_preview = this.findViewById(R.id.preview);
// Check for the camera permission before accessing the camera. If the
// permission is not granted yet, request permission.
int rc = ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (rc == PackageManager.PERMISSION_GRANTED) {
createCameraSource(true);
} else {
requestCameraPermission();
}
}
/**
* Handles the requesting of the camera permission. This includes
* showing a "Snackbar" message of why the permission is needed then
* sending the request.
*/
private void requestCameraPermission() {
Log.w(TAG, "Camera permission is not granted. Requesting permission");
final String[] permissions = new String[]{Manifest.permission.CAMERA};
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
ActivityCompat.requestPermissions(this, permissions, RC_HANDLE_CAMERA_PERM);
return;
}
View.OnClickListener listener = new View.OnClickListener() {
@Override
public void onClick(View view) {
ActivityCompat.requestPermissions(QrScanActivity.this, permissions,
RC_HANDLE_CAMERA_PERM);
}
};
}
/**
* Creates and starts the camera. Note that this uses a higher resolution in comparison
* to other detection examples to enable the barcode detector to detect small barcodes
* at long distances.
* <p>
* Suppressing InlinedApi since there is a check that the minimum version is met before using
* the constant.
*/
@SuppressLint("InlinedApi")
private void createCameraSource(boolean autoFocus) {
Context context = getApplicationContext();
// A barcode detector is created to track barcodes. An associated multi-processor instance
// is set to receive the barcode detection results, track the barcodes, and maintain
// graphics for each barcode on screen. The factory is used by the multi-processor to
// create a separate tracker instance for each barcode.
BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).setBarcodeFormats(Barcode.QR_CODE | Barcode.DATA_MATRIX | Barcode.AZTEC | Barcode.PDF417 | Barcode.CODE_39 |
Barcode.EAN_8 | Barcode.EAN_13 | Barcode.UPC_A | Barcode.UPC_E | Barcode.CODE_93 | Barcode.CODE_128 | Barcode.ITF | Barcode.CODABAR).build();
BarcodeTracker tracker = new BarcodeTracker(this);
barcodeDetector.setProcessor(
new FirstItemProcessor(barcodeDetector, tracker));
if (!barcodeDetector.isOperational()) {
// Note: The first time that an app using the barcode or face API is installed on a
// device, GMS will download a native libraries to the device in order to do detection.
// Usually this completes before the app is run for the first time. But if that
// download has not yet completed, then the above call will not detect any barcodes
// and/or faces.
//
// isOperational() can be used to check if the required native libraries are currently
// available. The detectors will automatically become operational once the library
// downloads complete on device.
Log.w(TAG, "Detector dependencies are not yet available.");
// Check for low storage. If there is low storage, the native library will not be
// downloaded, so detection will not become operational.
IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW);
boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null;
if (hasLowStorage) {
Toast.makeText(this, "low storage", Toast.LENGTH_LONG).show();
Log.w(TAG, "low storage error");
}
}
// Creates and starts the camera. Note that this uses a higher resolution in comparison
// to other detection examples to enable the barcode detector to detect small barcodes
// at long distances.
CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
.setFacing(CameraSource.CAMERA_FACING_BACK)
//.setRequestedPreviewSize(getWindow().getDecorView().getHeight(), getWindow().getDecorView().getWidth())
.setRequestedFps(30.0f);
builder = builder.setAutoFocusEnabled(autoFocus);
_cameraSource = builder.build();
}
/**
* Restarts the camera.
*/
@Override
protected void onResume() {
super.onResume();
startCameraSource();
((TracksApplication) getApplication()).set_currentClass(getClass().getSimpleName());
}
/**
* Stops the camera.
*/
@Override
protected void onPause() {
super.onPause();
if (_preview != null) {
_preview.stop();
}
}
/**
* Releases the resources associated with the camera source, the associated detectors, and the
* rest of the processing pipeline.
*/
@Override
protected void onDestroy() {
super.onDestroy();
if (_preview != null) {
_preview.release();
}
}
/**
* Callback for the result from requesting permissions. This method
* is invoked for every call on {@link #requestPermissions(String[], int)}.
* <p>
* <strong>Note:</strong> It is possible that the permissions request interaction
* with the user is interrupted. In this case you will receive empty permissions
* and results arrays which should be treated as a cancellation.
* </p>
*
* @param requestCode The request code passed in {@link #requestPermissions(String[], int)}.
* @param permissions The requested permissions. Never null.
* @param grantResults The grant results for the corresponding permissions
* which is either {@link PackageManager#PERMISSION_GRANTED}
* or {@link PackageManager#PERMISSION_DENIED}. Never null.
* @see #requestPermissions(String[], int)
*/
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String[] permissions,
@NonNull int[] grantResults) {
if (requestCode != RC_HANDLE_CAMERA_PERM) {
Log.d(TAG, "Got unexpected permission result: " + requestCode);
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
return;
}
if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Camera permission granted - initialize the camera source");
// we have permission, so create the camerasourc
createCameraSource(true);
return;
}
Log.e(TAG, "Permission not granted: results len = " + grantResults.length +
" Result code = " + (grantResults.length > 0 ? grantResults[0] : "(empty)"));
}
/**
* Starts or restarts the camera source, if it exists. If the camera source doesn't exist yet
* (e.g., because onResume was called before the camera source was created), this will be called
* again when the camera source is created.
*/
private void startCameraSource() throws SecurityException {
if (_cameraSource != null) {
try {
_preview.start(_cameraSource);
} catch (IOException e) {
Log.e(TAG, "Unable to start camera source.", e);
_cameraSource.release();
_cameraSource = null;
}
}
}
@Override
public void onBarcodeDetected(Barcode barcode) {
Intent data = new Intent();
data.putExtra(BARCODE_OBJECT, barcode);
setResult(CommonStatusCodes.SUCCESS, data);
finish();
}
}
如果有人有主意，我不知道怎么了...
答案 0 :(得分：0)
问题已“解决”，似乎是我收到的数据矩阵有问题。 由于我尝试使用IOS设备或Google Play商店应用程序等多种扫描仪进行扫描，因此所有内容也无法识别。