ticket_decoder

Optional arguments for instance creation of DecoderFacade.

• uic_public_key_xml_file = "cert/UIC_PublicKeys.xml"
  Relative path to the XML file containing UIC public keys you can obtain here: https://railpublickey.uic.org/ .
• vdv_certificate_ldif_file = "cert/VDV_Certificates.ldif"
  Relative path to the LDIF file containing VDV certificates to decrypt VDV barcode content.
• fail_on_decoder_error = false
  Fail when the aztec/barcode decoder gets an error if true or deliver an empty result when false.
• fail_on_interpreter_error = false
  Fail when the interpretation of the data gets an error if true or deliver an empty result when false.

Provided python API is in an early state and the class DecoderFacade supports 3 methods right now only.

• decode_bytes('...')

• decode_base64('...') is considered for the use case you decode the raw data from aztec-code in advance via zxing-cpp or other aztec-code-decoding library of your choice and you want to decode raw train ticket barcode data to json only. In this case, be careful with the output of the decoder to avoid string encodings like UTF8 or other multi-byte encodings. Ideally try to get access to the raw byte array and just encode those bytes to base64 before passing it to the method. If your aztec-code-decoder provides a string-type only and you are able to pass a character-encoding option, try using 'ISO 8859-1' and cast the result string to raw bytes.

• decode_files('...') detects and decodes aztec-codes from file or directories (PDF, image) and decodes barcode data to json. This is using zxing-cpp and opencv internally. It returns a dict (origin/input-path and json-string) of size x, while x is the amount of aztec-codes found on input. An image can contain always multiple barcodes, the return value is alway a mapping of origin to json content.

  • rotation_degree - Rotate image before processing for the given amount of degrees (default 0)
  • scale_percent - Scale image before processing in percent (default 100)
  • splitting_mode - Split image, 1st number specifies the no of parts to split, 2nd is the part used for processing, clockwise from top/left (default 11)
  • flipping_mode - Flip image around X if 1, around Y if 2, and around X and Y if 3 (default 0)

Example decoding directly from PDF or image

from ticket_decoder import DecoderFacade

decoder_facade = DecoderFacade()
print(decoder_facade.decode_files('path/2/your/ticket.pdf'))

Example decoding Aztec-Code in advance using zxingcpp and opencv on Python side

from ticket_decoder import DecoderFacade
from zxingcpp import read_barcodes
from cv2 import imread

image = imread('path/2/your/ticket.jpg')
if image is None:
    print("Image not found")
    exit(1)

barcodes = read_barcodes(image)
if barcodes is None:
    print("No barcodes found")
    exit(1)

decoder_facade = DecoderFacade(\
    uic_public_key_xml_file = "cert/UIC_PublicKeys.xml",\
    vdv_certificate_ldif_file = "cert/VDV_Certificates.ldif")

print(decoder_facade.decode_bytes(barcodes[0].bytes))