The goal of this program is to detect and decipher one or several QR codes in a picture.

In order to decipher QR codes, we will use the QRLight library, installed as follow:
apt-get install libzbar0 libzbar-dev
pip install zbarlight
We will also use a number of standard Python libraries.

 from PIL import Image
 import zbarlight
 from subprocess import Popen, PIPE
 import sys
 import datetime

The program allows exactly one argument: the IP address of the Raspberry Pi whose camera we're going to be using.
To avoid any issue, we check that it is a valid IP address with the following function:

 def isValidIPV4(adr):
   nums = adr.split('.')
   if len(nums) != 4:
       return False
   try:
       return all(0 <= int(num) < 256 for num in nums)
   except ValueError:
       return False

Work in Progress…