How to encode and decode a file backed up as a series of printed QR codes

QRBackup.sh

# How to encode and decode a file backed up as a series of printed QR codes

# Install the required tools

sudo apt-get update
sudo apt-get install zbar-tools imagemagick qrencode

################################################################################

# Convert the file to a base 64 encoded format.  Probably not needed as QR codes
# are capable of encoding 8-bit binary data.  I just do it to be safe.

base64 keyfile.kdb > keyfile.64

# Split this file into a series of smaller files that can be converted to QR
# codes.  Use your judgement.

split -n 6 keyfile.64 Passwords_kdb_64

# Encode each portion of the split file as a QR code.  The -l H option gives
# maximum error correction capability by increasing redundancy in the code.

for file in ./Passwords_kdb_64*; do qrencode -l H -o $file.png < $file; done

# Combine 6 QR codes into one image containing 3 rows of 2 codes with
# filenames under each code.

montage -label '%f' *.png -geometry '1x1<' -tile 2x3 Passwords_kdb_64.png

################################################################################

# Scan each of the QR codes in order and redirect the output to a file.  Each
# code is on a new line with a header identifying the type of code scanned.  The
# new lines and headers need to be removed.  This was done manually.

zbarcam > keyfile.64

# The the base 64 code that has just been read and convert it back to the
# original binary file.

base64 -d keyfile.64 > keyfile.kdb