I am using the /processBarcodeField?barcodeType=autodetect  method
and get the following results :

<?xml version="1.0" encoding="utf-8" standalone="yes"?><document xmlns="@link" xmlns:xsi="@link" xsi:schemaLocation="@link" version="1.0"><field left="0" top="0" right="4032" bottom="3024" type="barcode"><value encoding="Base64">XgA=</value></field></document>

I am sending an image of the drivers license barcode.