QrCodeDataFromImage.java

 @Override
    protected Result doInBackground(Void... params)
    {
        try {
            InputStream inputStream = activity.getContentResolver().openInputStream(uri);
            Bitmap bitmap = BitmapFactory.decodeStream(inputStream);

            if (bitmap == null) {
                Log.e(TAG, "uri is not a bitmap," + uri.toString());
                return null;
            }

            int width = bitmap.getWidth(), height = bitmap.getHeight();
            int[] pixels = new int[width * height];
            bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
            bitmap.recycle();
            bitmap = null;

            RGBLuminanceSource source = new RGBLuminanceSource(width, height, pixels);
            BinaryBitmap bBitmap = new BinaryBitmap(new HybridBinarizer(source));
            MultiFormatReader reader = new MultiFormatReader();
            
            try {
                Result result = reader.decode(bBitmap);
                return result;
            } catch (NotFoundException e) {
                Log.e(TAG, "decode exception", e);
                return null;
            }
        } catch (FileNotFoundException e) {
            Log.e(TAG, "can not open file" + uri.toString(), e);
            return null;
        }
    }