Python Extension: Barcode and QR Code SDK

The project is a CPython binding to Dynamsoft C/C++ Barcode Reader SDK. It aims to help developers build Python barcode and QR code scanning apps on Windows, Linux and macOS. Besides desktop PCs, it can work well on embedded and IoT devices such as Raspberry Pi and Jetson Nano. You are free to customize the Python API for Dynamsoft Barcode Reader.

About Dynamsoft Barcode Reader

• Dynamsoft C/C++ Barcode Reader SDK v9.4.0
• Get a 30-day FREE trial license to activate the SDK.

Supported Python Edition

• Python 3.x

Install Dependencies

pip install opencv-python

Command-line Usage

$ scanbarcode <file-name> -l <license-key>

# Show the image with OpenCV
$ scanbarcode <file-name> -u 1 -l <license-key>

How to Build the Python Barcode and QR Code Extension

• Create a source distribution:

  python setup.py sdist
  

• setuptools:

  python setup_setuptools.py build
  python setup_setuptools.py develop # Copy libraries to barcodeQrSDK folder
  

• scikit-build:

  python setup.py build
  python setup.py develop # Copy libraries to barcodeQrSDK folder
  

• Build wheel:

  pip wheel . --verbose
  # Or
  python setup_setuptools.py bdist_wheel
  # Or
  python setup.py bdist_wheel
  

Quick Start

• Console App

  import barcodeQrSDK
  
  # set license
  barcodeQrSDK.initLicense("DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ==")
  
  reader = barcodeQrSDK.createInstance()
  
  results, elapsed_time = reader.decodeFile("test.png")
  for result in results:
      print(result.format)
      print(result.text)
      print(result.x1)
      print(result.y1)
      print(result.x2)
      print(result.y2)
      print(result.x3)
      print(result.y3)
      print(result.x4)
      print(result.y4)
  

• Video App

  import barcodeQrSDK
  import numpy as np
  import cv2
  import json
  
  g_results = None
  
  def callback(results, elapsed_time):
      global g_results
      g_results = (results, elapsed_time)
  
  def run():
      # set license
      barcodeQrSDK.initLicense("DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ==")
  
      # initialize barcode scanner
      scanner = barcodeQrSDK.createInstance()
      params = scanner.getParameters()
      # Convert string to JSON object
      json_obj = json.loads(params)
      # json_obj['ImageParameter']['ExpectedBarcodesCount'] = 999
      params = json.dumps(json_obj)
      ret = scanner.setParameters(params)
  
      scanner.addAsyncListener(callback)
  
      cap = cv2.VideoCapture(0)
      while True:
          ret, image = cap.read()
          if image is not None:
              scanner.decodeMatAsync(image)
  
          if g_results != None:
              print('Elapsed time: ' + str(g_results[1]) + 'ms')
              cv2.putText(image, 'Elapsed time: ' + str(g_results[1]) + 'ms', (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 0, 255), 2)
              for result in g_results[0]:
                  x1 = result.x1
                  y1 = result.y1
                  x2 = result.x2
                  y2 = result.y2
                  x3 = result.x3
                  y3 = result.y3
                  x4 = result.x4
                  y4 = result.y4
  
                  cv2.drawContours(image, [np.int0([(x1, y1), (x2, y2), (x3, y3), (x4, y4)])], 0, (0, 255, 0), 2)
                  cv2.putText(image, result.text, (x1, y1), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 255, 0), 2)
  
          cv2.imshow('Barcode QR Code Scanner', image)
          ch = cv2.waitKey(1)
          if ch == 27:
              break
  
      scanner.clearAsyncListener()
  
  if __name__ == '__main__':
      run()
  

  

Methods

• barcodeQrSDK.initLicense('YOUR-LICENSE-KEY') # set barcode SDK license globally

  barcodeQrSDK.initLicense("DLS2eyJoYW5kc2hha2VDb2RlIjoiMjAwMDAxLTE2NDk4Mjk3OTI2MzUiLCJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSIsInNlc3Npb25QYXNzd29yZCI6IndTcGR6Vm05WDJrcEQ5YUoifQ==")
  

• barcodeQrSDK.createInstance() # create a barcode reader instance

  reader = barcodeQrSDK.createInstance()
  

• decodeFile(filename) # decode barcode and QR code from an image file

  results, elapsed_time = reader.decodeFile("test.png")
  

• decodeMat(Mat image) # decode barcode and QR code from Mat

  image = cv2.imread("test.png")
  results = reader.decodeMat(image)
  for result in results:
      print(result.format)
      print(result.text)
      print(result.x1)
      print(result.y1)
      print(result.x2)
      print(result.y2)
      print(result.x3)
      print(result.y3)
      print(result.x4)
      print(result.y4)
  

• getParameters() # return JSON string

  params = reader.getParameters()
  

• setParameters(JSON string) # set barcode SDK parameters

  import json
  json_obj = json.loads(params)
  json_obj['ImageParameter']['DPMCodeReadingModes'][0]['Mode'] = 'DPMCRM_GENERAL'
  json_obj['ImageParameter']['LocalizationModes'][0]['Mode'] = 'LM_STATISTICS_MARKS'
  params = json.dumps(json_obj)
  ret = reader.setParameters(params)
  

• addAsyncListener(callback function) # start a native thread and register a Python function for receiving barcode QR code results

• decodeMatAsync(<opencv mat data>) # decode barcode QR code from OpenCV Mat asynchronously

  def callback(results, elapsed_time):
      print(results)
  
  import cv2
  image = cv2.imread("test.png")
  reader.addAsyncListener(callback)
  reader.decodeMatAsync(image)
  sleep(1)
  

• clearAsyncListener() # stop the native thread and clear the registered Python function

• decodeBytes(bytes, width, height, stride, imageformat) # 0: gray; 1: rgb888

  import cv2
  image = cv2.imread("test.png")
  results, elapsed_time = scanner.decodeBytes(image.tobytes(), image.shape[1], image.shape[0], image.strides[0], barcodeQrSDK.ImagePixelFormat.IPF_BGR_888)
  

• decodeBytesAsync # decode image byte array asynchronously

  def callback(results, elapsed_time):
      print(results)
  
  import cv2
  image = cv2.imread("test.png")
  imagebytes = image.tobytes()
  scanner.decodeBytesAsync(image.tobytes(), image.shape[1], image.shape[0], image.strides[0], barcodeQrSDK.ImagePixelFormat.IPF_BGR_888)
  sleep(1)
  

Online Documentation for Dynamsoft C/C++ Barcode SDK

To customize Python API based on C/C++, please refer to the online documentation.

Supported Barcode Symbologies

• Linear Barcodes (1D)

  • Code 39 (including Code 39 Extended)
  • Code 93
  • Code 128
  • Codabar
  • Interleaved 2 of 5
  • EAN-8
  • EAN-13
  • UPC-A
  • UPC-E
  • Industrial 2 of 5

• 2D Barcodes:

  • QR Code (including Micro QR Code)
  • Data Matrix
  • PDF417 (including Micro PDF417)
  • Aztec Code
  • MaxiCode (mode 2-5)

• Patch Code

• GS1 Composite Code