Google Barcode Scanning ML kit not working for android 8.1 and below

Question

I'm new to Android development and currently working on an app which lets the user scan the QR code using either camera or choosing a picture from Gallery using Barcode scanning kit. The app works completely fine for Android 9 (Api level 28) and above. The app works fine for all versions while scanning using camera. But for android 8 and below, I'm unable to scan any QR code if I choose a picture from gallery. I searched everywhere but didn't find any solution.

Here's the code I tried: -

mChoosePhoto = registerForActivityResult(new ActivityResultContracts.GetContent(), result -> {
    InputImage image;
    BarcodeScannerOptions options =
            new BarcodeScannerOptions.Builder()
                    .setBarcodeFormats(Barcode.FORMAT_QR_CODE)
                    .build();
    BarcodeScanner scanner = BarcodeScanning.getClient(options);
    Log.v("myUri", String.valueOf(result));
    try {
        image = InputImage.fromFilePath(this, result);
        scanner.process(image)
            .addOnSuccessListener(MainActivity.this::processResult)
            .addOnFailureListener(e -> {
                // Task failed with an exception
                Toast.makeText(MainActivity.this, "Failed to scan.", Toast.LENGTH_SHORT).show();
                e.printStackTrace();
            });
    } catch (IOException e) {
        e.printStackTrace();
    }
});

And then in processResult() Method

private void processResult(List<Barcode> barcodes){
        for (Barcode barcode: barcodes) {

            Vibrator vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
            vibrator.vibrate(100);

//            Rect bounds = barcode.getBoundingBox();
//            Point[] corners = barcode.getCornerPoints();
//
//            String rawValue = barcode.getRawValue();

            int valueType = barcode.getValueType();
            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();
                    Toast.makeText(this, title + " " + url, Toast.LENGTH_SHORT).show();
                    break;
                case Barcode.TYPE_TEXT:
                    String text = barcode.getDisplayValue();
                    Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
            }
        }
    }

`InputImage.fromFilePath(this, result);` That does not look correct. — blackapps, Oct 26 '22 at 15:48
@blackapps thanks for replying. Look at this [link](https://developers.google.com/ml-kit/vision/barcode-scanning/android#using-a-file-uri) as they clearly mentioned the way to convert Uri into InputImage. "result" is the content style Uri e.g. content://com.android.providers.media.documents/document/image%3A328944 — Yatik, Oct 26 '22 at 16:54
@blackapps here's the launch(): - `binding.selectFromGallery.setOnClickListener(view -> mChoosePhoto.launch("image/*"));` — Yatik, Oct 26 '22 at 16:56
`I'm unable to scan any QR code if I choose a picture from gallery.` Too vague. What happens exactly? Or what exactly does not happen. Does an InputImage display the picture normally? At which statement things go wrong? — blackapps, Oct 26 '22 at 19:38
@blackapps yea I should have added that code. Okay lemme explain assuming two scenarios. Suppose I'm using android 9 or above, I clicked the button to choose QR from Gallery. It'll return me the `result` Uri and then in **try** block it'll convert Uri into InputImage and then [here](https://gist.github.com/yatiksihag01/d3554c8c6a66ae86c645876d382a26cd/#file-mainactivity-java-L24-L30) it returns me the `List barcodes` of size one ofcousre. But for android 8.1 or below, I get `result` Uri, in **try** block it convert it into InputImage `image` but then... — Yatik, Oct 27 '22 at 03:32
... [here](https://gist.github.com/yatiksihag01/d3554c8c6a66ae86c645876d382a26cd/#file-mainactivity-java-L24-L30) it returns me empty List barcodes and I've no idea why this returns empty List of barcodes even when the image contains a QR Code. The same is working completely fine in Android 9 and above. — Yatik, Oct 27 '22 at 03:35
Instead of 'here' you could just have said 'in onResponse()'. — blackapps, Oct 27 '22 at 06:20
What is the resolution of the picture that goes wrong? Is it the same picture that you use in other devices? — blackapps, Oct 27 '22 at 06:22
@blackapps thank you so much. Actually, I was using different pictures on those two devices. Then I tried the same picture which I was using in Android 9 in Android 8 and it worked. The one I was using in android 8 doesn't work in Android 9 and 12 too. The problem I found is that it scans [this](https://ibb.co/cX7bzsr) type of picture but not [this](https://ibb.co/mNR97X3) . The QR code size in both pictures is 512*512. I mean it scans if QR code doesn't fill the whole picture. Can you please give me some hint that what I should do? — Yatik, Oct 27 '22 at 14:09
You could place the bitmap with qr code on a white bitmap that is slightly larger so it resembles the good one with the extra white borders. — blackapps, Oct 27 '22 at 14:59
Hi @blackapps, I filed the bug report. But how can I place a QR code bitmap over a white image? You mean something like [bitmapOverlayToCenter()](https://stackoverflow.com/questions/10616777/how-to-merge-to-two-bitmap-one-over-another) method? — Yatik, Oct 28 '22 at 04:21
I have no idea what that code does. But you only have to copy your bitmap over a slightly bigger white or black bitmap. — blackapps, Oct 28 '22 at 06:09
Hi @blackapps, google recognized this issue and they said they'll fix it soon. Thank you so much for your help:) — Yatik, Oct 28 '22 at 17:27

Google Barcode Scanning ML kit not working for android 8.1 and below

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