ML Kit を使用してバーコードをスキャンする（Android）

private class YourAnalyzer implements ImageAnalysis.Analyzer {

    @Override
    public void analyze(ImageProxy imageProxy) {
        Image mediaImage = imageProxy.getImage();
        if (mediaImage != null) {
          InputImage image =
                InputImage.fromMediaImage(mediaImage, imageProxy.getImageInfo().getRotationDegrees());
          // Pass image to an ML Kit Vision API
          // ...
        }
    }
}

private val ORIENTATIONS = SparseIntArray()

init {
    ORIENTATIONS.append(Surface.ROTATION_0, 0)
    ORIENTATIONS.append(Surface.ROTATION_90, 90)
    ORIENTATIONS.append(Surface.ROTATION_180, 180)
    ORIENTATIONS.append(Surface.ROTATION_270, 270)
}

/**
 * Get the angle by which an image must be rotated given the device's current
 * orientation.
 */
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Throws(CameraAccessException::class)
private fun getRotationCompensation(cameraId: String, activity: Activity, isFrontFacing: Boolean): Int {
    // Get the device's current rotation relative to its "native" orientation.
    // Then, from the ORIENTATIONS table, look up the angle the image must be
    // rotated to compensate for the device's rotation.
    val deviceRotation = activity.windowManager.defaultDisplay.rotation
    var rotationCompensation = ORIENTATIONS.get(deviceRotation)

    // Get the device's sensor orientation.
    val cameraManager = activity.getSystemService(CAMERA_SERVICE) as CameraManager
    val sensorOrientation = cameraManager
            .getCameraCharacteristics(cameraId)
            .get(CameraCharacteristics.SENSOR_ORIENTATION)!!

    if (isFrontFacing) {
        rotationCompensation = (sensorOrientation + rotationCompensation) % 360
    } else { // back-facing
        rotationCompensation = (sensorOrientation - rotationCompensation + 360) % 360
    }
    return rotationCompensation
}
MLKitVisionImage.kt

private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
static {
    ORIENTATIONS.append(Surface.ROTATION_0, 0);
    ORIENTATIONS.append(Surface.ROTATION_90, 90);
    ORIENTATIONS.append(Surface.ROTATION_180, 180);
    ORIENTATIONS.append(Surface.ROTATION_270, 270);
}

/**
 * Get the angle by which an image must be rotated given the device's current
 * orientation.
 */
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
private int getRotationCompensation(String cameraId, Activity activity, boolean isFrontFacing)
        throws CameraAccessException {
    // Get the device's current rotation relative to its "native" orientation.
    // Then, from the ORIENTATIONS table, look up the angle the image must be
    // rotated to compensate for the device's rotation.
    int deviceRotation = activity.getWindowManager().getDefaultDisplay().getRotation();
    int rotationCompensation = ORIENTATIONS.get(deviceRotation);

    // Get the device's sensor orientation.
    CameraManager cameraManager = (CameraManager) activity.getSystemService(CAMERA_SERVICE);
    int sensorOrientation = cameraManager
            .getCameraCharacteristics(cameraId)
            .get(CameraCharacteristics.SENSOR_ORIENTATION);

    if (isFrontFacing) {
        rotationCompensation = (sensorOrientation + rotationCompensation) % 360;
    } else { // back-facing
        rotationCompensation = (sensorOrientation - rotationCompensation + 360) % 360;
    }
    return rotationCompensation;
}

val image = InputImage.fromMediaImage(mediaImage, rotation)
MLKitVisionImage.kt

val image: InputImage
try {
    image = InputImage.fromFilePath(context, uri)
} catch (e: IOException) {
    e.printStackTrace()
}
MLKitVisionImage.kt

val image = InputImage.fromByteBuffer(
        byteBuffer,
        /* image width */ 480,
        /* image height */ 360,
        rotationDegrees,
        InputImage.IMAGE_FORMAT_NV21 // or IMAGE_FORMAT_YV12
)
MLKitVisionImage.kt
// Or:
val image = InputImage.fromByteArray(
        byteArray,
        /* image width */ 480,
        /* image height */ 360,
        rotationDegrees,
        InputImage.IMAGE_FORMAT_NV21 // or IMAGE_FORMAT_YV12
)
MLKitVisionImage.kt

InputImage image = InputImage.fromByteBuffer(byteBuffer,
        /* image width */ 480,
        /* image height */ 360,
        rotationDegrees,
        InputImage.IMAGE_FORMAT_NV21 // or IMAGE_FORMAT_YV12
);
MLKitVisionImage.java
// Or:
InputImage image = InputImage.fromByteArray(
        byteArray,
        /* image width */480,
        /* image height */360,
        rotation,
        InputImage.IMAGE_FORMAT_NV21 // or IMAGE_FORMAT_YV12
);
MLKitVisionImage.java

val image = InputImage.fromBitmap(bitmap, 0)
MLKitVisionImage.kt

val scanner = BarcodeScanning.getClient()
// Or, to specify the formats to recognize:
// val scanner = BarcodeScanning.getClient(options)
BarcodeScanningActivity.kt

BarcodeScanner scanner = BarcodeScanning.getClient();
// Or, to specify the formats to recognize:
// BarcodeScanner scanner = BarcodeScanning.getClient(options);
BarcodeScanningActivity.java

val result = scanner.process(image)
        .addOnSuccessListener { barcodes ->
            // Task completed successfully
            // ...
        }
        .addOnFailureListener {
            // Task failed with an exception
            // ...
        }
BarcodeScanningActivity.kt

Task<List<Barcode>> result = scanner.process(image)
        .addOnSuccessListener(new OnSuccessListener<List<Barcode>>() {
            @Override
            public void onSuccess(List<Barcode> barcodes) {
                // Task completed successfully
                // ...
            }
        })
        .addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                // Task failed with an exception
                // ...
            }
        });
BarcodeScanningActivity.java

for (barcode in barcodes) {
    val bounds = barcode.boundingBox
    val corners = barcode.cornerPoints

    val rawValue = barcode.rawValue

    val valueType = barcode.valueType
    // See API reference for complete list of supported types
    when (valueType) {
        Barcode.TYPE_WIFI -> {
            val ssid = barcode.wifi!!.ssid
            val password = barcode.wifi!!.password
            val type = barcode.wifi!!.encryptionType
        }
        Barcode.TYPE_URL -> {
            val title = barcode.url!!.title
            val url = barcode.url!!.url
        }
    }
}
BarcodeScanningActivity.kt

for (Barcode barcode: barcodes) {
    Rect bounds = barcode.getBoundingBox();
    Point[] corners = barcode.getCornerPoints();

    String rawValue = barcode.getRawValue();

    int valueType = barcode.getValueType();
    // See API reference for complete list of supported types
    switch (valueType) {
        case Barcode.TYPE_WIFI:
            String ssid = barcode.getWifi().getSsid();
            String password = barcode.getWifi().getPassword();
            int type = barcode.getWifi().getEncryptionType();
            break;
        case Barcode.TYPE_URL:
            String title = barcode.getUrl().getTitle();
            String url = barcode.getUrl().getUrl();
            break;
    }
}
BarcodeScanningActivity.java