Detailed explanation of Python two dimensional code generation and identification example

Preface

In the development of JavaWeb, Zxing is generally used to generate and recognize 2D codes, but the recognition of Zxing is somewhat unsatisfactory, and the recognition rate of many relatively fuzzy 2D codes is very low. However, as far as the latest version of the test is concerned, the recognition rate has been significantly improved.

Contrast

Before touching Python, I used the client of Zbar to identify, and measured about several hundred relatively fuzzy pictures. The recognition speed of Zbar is much faster, and the recognition rate is slightly more accurate than that of Zxing. However, if it is slightly blurred, it cannot be recognized. In contrast, the recognition effect of WeChat and Alipay is against the sky.

Code case

# -*- coding:utf-8 -*-
import os
import qrcode
import time
from PIL import Image
from pyzbar import pyzbar

"""
#  Upgrade  pip  And install the 3 Square library 
pip install -U pip
pip install Pillow
pip install pyzbar
pip install qrcode
"""


def make_qr_code_easy(content, save_path=None):
  """
  Generate QR Code by default
  :param content: The content encoded in QR Codeparams
  :param save_path: The path where the generated QR Code image will be saved in.
           If the path is not given the image will be opened by default.
  """
  img = qrcode.make(data=content)
  if save_path:
    img.save(save_path)
  else:
    img.show()


def make_qr_code(content, save_path=None):
  """
  Generate QR Code by given params
  :param content: The content encoded in QR Code
  :param save_path: The path where the generated QR Code image will be saved in.
           If the path is not given the image will be opened by default.
  """
  qr_code_maker = qrcode.QRCode(version=2,
                 error_correction=qrcode.constants.ERROR_CORRECT_M,
                 box_size=8,
                 border=1,
                 )
  qr_code_maker.add_data(data=content)
  qr_code_maker.make(fit=True)
  img = qr_code_maker.make_image(fill_color="black", back_color="white")
  if save_path:
    img.save(save_path)
  else:
    img.show()


def make_qr_code_with_icon(content, icon_path, save_path=None):
  """
  Generate QR Code with an icon in the center
  :param content: The content encoded in QR Code
  :param icon_path: The path of icon image
  :param save_path: The path where the generated QR Code image will be saved in.
           If the path is not given the image will be opened by default.
  :exception FileExistsError: If the given icon_path is not exist.
                This error will be raised.
  :return:
  """
  if not os.path.exists(icon_path):
    raise FileExistsError(icon_path)

  # First, generate an usual QR Code image
  qr_code_maker = qrcode.QRCode(version=4,
                 error_correction=qrcode.constants.ERROR_CORRECT_H,
                 box_size=8,
                 border=1,
                 )
  qr_code_maker.add_data(data=content)
  qr_code_maker.make(fit=True)
  qr_code_img = qr_code_maker.make_image(fill_color="black", back_color="white").convert('RGBA')

  # Second, load icon image and resize it
  icon_img = Image.open(icon_path)
  code_width, code_height = qr_code_img.size
  icon_img = icon_img.resize((code_width // 4, code_height // 4), Image.ANTIALIAS)

  # Last, add the icon to original QR Code
  qr_code_img.paste(icon_img, (code_width * 3 // 8, code_width * 3 // 8))

  if save_path:
    qr_code_img.save(save_path)
  else:
    qr_code_img.show()


def decode_qr_code(code_img_path):
  """
  Decode the given QR Code image, and return the content
  :param code_img_path: The path of QR Code image.
  :exception FileExistsError: If the given code_img_path is not exist.
                This error will be raised.
  :return: The list of decoded objects
  """
  if not os.path.exists(code_img_path):
    raise FileExistsError(code_img_path)

  # Here, set only recognize QR Code and ignore other type of code
  return pyzbar.decode(Image.open(code_img_path), symbols=[pyzbar.ZBarSymbol.QRCODE], scan_locations=True)


if __name__ == "__main__":

  # #  Simple version 
  # make_qr_code_easy("make_qr_code_easy", "make_qr_code_easy.png")
  # results = decode_qr_code("make_qr_code_easy.png")
  # if len(results):
  #   print(results[0].data.decode("utf-8"))
  # else:
  #   print("Can not recognize.")
  #
  # #  Parameter version 
  # make_qr_code("make_qr_code", "make_qr_code.png")
  # results = decode_qr_code("make_qr_code.png")
  # if len(results):
  #   print(results[0].data.decode("utf-8"))
  # else:
  #   print("Can not recognize.")
  #
  #  Belt center  logo  Adj. 
  # make_qr_code_with_icon("https://blog.52itstyle.vip", "icon.jpg", "make_qr_code_with_icon.png")
  # results = decode_qr_code("make_qr_code_with_icon.png")
  # if len(results):
  #   print(results[0].data.decode("utf-8"))
  # else:
  #   print("Can not recognize.")

  #  Identification answer sheet 2 Dimension code  16  Recognition failure 
  t1 = time.time()
  count = 0
  for i in range(1, 33):
    results = decode_qr_code(os.getcwd()+"\\img\\"+str(i)+".png")
    if len(results):
      print(results[0].data.decode("utf-8"))
    else:
      print("Can not recognize.")
      count += 1
  t2 = time.time()
  print(" Identify the number of failures :" + str(count))
  print(" Test time :" + str(int(round(t2 * 1000))-int(round(t1 * 1000))))

Thirty-two carefully selected fuzzy 2D codes were tested:

 Identify the number of failures :1
 Test time :130

Three failed to identify with the latest version of Zxing.

Source code

https://gitee.com/52itstyle/Python/tree/master/Day13