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androidkotlinbarcode-scannergoogle-mlkitdatamatrix

Unknown encoding error when parsing DataMatrix with ISO-8859-1 encoding

Developing an Android application to scan Data Matrix codes using Google's MLKit, I'm unable to parse codes with data encoded in ISO-8859-1 encoding and containing Non-ASCII characters.

Here's an example: DataMatrix failing with ML Kit

val options = BarcodeScannerOptions.Builder()
    .setBarcodeFormats(Barcode.FORMAT_DATA_MATRIX)
    .build()
val scanner = BarcodeScanning.getClient(options)
scanner.process(image).addOnSuccessListener { barcodes ->
  val barcode = barcodes.firstOrNull()
  Log.i(TAG, barcode?.rawValue)
  Log.i(TAG, String(barcode?.rawBytes!!, StandardCharsets.ISO_8859_1))
}

Both log statements return a string representing "Unknown encoding" (literally).

I'm using the latest version of MLKit's barcode-scanning library:

implementation 'com.google.mlkit:barcode-scanning:16.1.1

ZXing does the job, but it's having much more difficulties recognizing real life, not-so-perfect scans.

Any idea, any hint?

Solution

  • With the latest version of the ML Kit Barcode Scanning library 16.1.2, the rawBytes method now returns the expected content of the QR code, also for non-unicode encodings.

    implementation 'com.google.mlkit:barcode-scanning:16.1.2'