问题
I am implementing barcode scanner in my application. I would like to limit my detection area. followed the below logic but i doesn't work properly in some of the devices.
//Trying to crop the center portion of the frame:
public class BoxDetector extends Detector {
private Detector mDelegate;
private int mBoxWidth, mBoxHeight;
public BoxDetector(Detector delegate, int boxWidth, int boxHeight) {
mDelegate = delegate;
mBoxWidth = boxWidth;
mBoxHeight = boxHeight;
}
public SparseArray detect(Frame frame) {
int width = frame.getMetadata().getWidth();
int height = frame.getMetadata().getHeight();
int right = (width / 2) + (mBoxHeight / 2);
int left = (width / 2) - (mBoxHeight / 2);
int bottom = (height / 2) + (mBoxWidth / 2);
int top = (height / 2) - (mBoxWidth / 2);
YuvImage yuvImage = new YuvImage(frame.getGrayscaleImageData().array(), ImageFormat.NV21, width, height, null);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
yuvImage.compressToJpeg(new Rect(left, top, right, bottom), 100, byteArrayOutputStream);
byte[] jpegArray = byteArrayOutputStream.toByteArray();
Bitmap bitmap = BitmapFactory.decodeByteArray(jpegArray, 0, jpegArray.length);
Frame croppedFrame =
new Frame.Builder()
.setBitmap(bitmap)
.setRotation(frame.getMetadata().getRotation())
.build();
return mDelegate.detect(croppedFrame);
}
public boolean isOperational() {
return mDelegate.isOperational();
}
public boolean setFocus(int id) {
return mDelegate.setFocus(id);
}
}
//This my barcode detector building class:
Detector<Barcode> barcodeDetector = new BoxDetector(new BarcodeDetector.Builder(context).setBarcodeFormats(Barcode.ALL_FORMATS).build(), metrics.widthPixels, metrics.heightPixels);
//BoxDetector myDetector = new BoxDetector(barcodeDetector, metrics.widthPixels, metrics.heightPixels);
BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay, this);
barcodeDetector.setProcessor(
new MultiProcessor.Builder<>(barcodeFactory).build());
@SuppressWarnings("SuspiciousNameCombination")
CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
.setFacing(CameraSource.CAMERA_FACING_BACK)
.setRequestedPreviewSize(metrics.heightPixels, metrics.widthPixels)
.setRequestedFps(30.0f);
Where and what i am missing. Referred all github thread related to this issue. But i couldn't find the solution. Please suggest some link or solution for this issue.
回答1:
BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context)
.setBarcodeFormats(Barcode.ALL_FORMATS)
.build();
//qrBorder 280dp
DisplayMetrics dm = getResources().getDisplayMetrics();
int height = dm.heightPixels;
int wight = dm.widthPixels;
BoxDetector bx = new BoxDetector(barcodeDetector,pxFromDp(280), height, wight);
BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay, this);
bx.setProcessor(
new MultiProcessor.Builder<>(barcodeFactory).build());
来源:https://stackoverflow.com/questions/48923619/vision-api-barcode-restrict-the-detection-area-to-center-rect-of-screen