Step 1: Setting Up and Using Python 3 Virtualenv on Mac
Step 2: Install OpenCV 3 for Python on Mac
Step 3: OpenCV and Python Webcam Quick Test
Step 4: Installing ZBar (with Python Bindings) for Barcode Decoding

Published August 28, 2018

QR Code Reader Decoder (Mac/Raspberry Pi)

A QR code reader based on ZBar and OpenCV with Python.

IntermediateFull instructions provided3 hours14,150

QR Code Reader Decoder (Mac/Raspberry Pi)

Things used in this project

Hardware components

Raspberry Pi 3 Model B

Raspberry Pi Camera Module

Software apps and online services

OpenCV

Story

Step 1: Setting Up and Using Python 3 Virtualenv on Mac

$ brew install python3

· Pip3 isinstalled with Python3

Installation

To install virtualenv via pip run:

$ pip3 install virtualenv

Usage

Creation of virtualenv:

$ virtualenv -p python3 <desired-path>

Activate the virtualenv:

$ source <desired-path>/bin/activate

Deactivate the virtualenv:

$ deactivate

Step 2: Install OpenCV 3 for Python on Mac

1. Install and update homebrew

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
$ brew update

2. Tap homebrew-bio

$ brew tap brewsci/bio

3. Install OpenCV with homebrew including Python 3

$ brew install opencv3 --with-contrib --with-python3

4. Change into the OpenCV directory

Since weinstalled OpenCV with Homebrew, the package was should be listed in homebrew'sCellar (/usr/local/Cellar/) To see what's in the Brew Cellar, do this:

$ brew list
# or
$ ls /usr/local/Cellar/

Now, let's gointo the opencv directory.

$ cd /usr/local/Cellar/opencv
$ ls 
3.3.0_3 3.3.1_1

In my case, the numbers 3.3.0_3 and 3.3.1_1 are different versions of OpenCV. This is a goodthing. You'll want the highest version number listed here, in my case it's 3.3.1_1

$ cd 3.3.1_1
$ pwd 
/usr/local/Cellar/opencv/3.3.1_1

Awesome. Thisis the OpenCV Version we want to use. We're very close to getting the cv2.<version>.so we need.

5. Find the cv2.<version>.so file in OpenCV

Okay, so wehave the OpenCV version we're going to use and where it's located. Now we needto link it to our version of Python.

· What Python version are you using?

·         $ python --version
·         Python 2.7.10
·         $ python3 --version
·         Python 3.6.3

I have Python 3.6 and Python 2.7 installed on my system. If I want both versionsto have OpenCV, I can. I'll just need to add the correct cv2.<version>.so to your Python's site packages. We'll do thispart in the next step. In the meantime, let's get the cv2.<version>.so for each version of Python. You can installwhatever version you want.

Get the Python 3.6 cv2.<version>.so file path:

$ cd /usr/local/Cellar/opencv/3.3.1_1
$ ls
INSTALL_RECEIPT.json    bin         share
LICENSE         include
README.md       lib
$ cd lib
ls 
# /usr/local/Cellar/opencv/3.3.1_1/lib
...
...
python2.7
python3.6 
...
...
$ cd python3.6
$ cd site-packages
$ pwd
/usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages
$ ls
cv2.cpython-36m-darwin.so # this name might be different but... bingo!

OpenCV Python3.6 Path: /usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages/cv2.cpython-36m-darwin.so

Get the Python 2.7 cv2.<version>.so file path:

$ cd /usr/local/Cellar/opencv/3.3.1_1
$ ls
INSTALL_RECEIPT.json    bin         share
LICENSE         include
README.md       lib
$ cd lib
ls 
# /usr/local/Cellar/opencv/3.3.1_1/lib
...
...
python2.7
python3.6 
...
...
$ cd python2.7
$ cd site-packages
$ pwd
/usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages
$ ls
cv2.so # this name might be different but... bingo!

OpenCV Python2.7 Path: /usr/local/Cellar/opencv/3.3.1_1/lib/python2.7/site-packages/cv2.so

Add OpenCV to Virtualenvs

All you haveto do is add the cv2.<version>.so to your virtualenv's site-packages. Example:

$ mkdir ~/Dev
$ cd ~/Dev
$ virtualenv -p python3 newcvtest
$ cd newcvtest
$ source bin/activate
(newcvtest) $ python --version 
Python 3.6.5
(newcvtest) $ pip install numpy
(newcvtest) $ cd lib/python3.6/site-packages
(newcvtest) $ ln -S /usr/local/Cellar/opencv/3.3.1_1/lib/python3.6/site-packages/cv2.cpython-36m-darwin.so cv2.so
$ mkdir ~/Dev
$ cd ~/Dev
$ virtualenv -p python2 newcvtestpy2
$ cd newcvtestpy2
$ source bin/activate
(newcvtestpy2) $ python --version 
Python 2.7.10
(newcvtestpy2) $ pip install numpy
(newcvtestpy2) $ cd lib/python3.6/site-packages
(newcvtestpy2) $ ln -S /usr/local/Cellar/opencv/3.3.1_1/lib/python2.7/site-packages/cv2.so cv2.so

6. Test OpenCV Installation

$ python3  # or python2
>>> import cv2
>>> print(cv2.__version__)
3.3.1 # your version may be a newer one

Step 3: OpenCV and Python Webcam Quick Test

Create a Python file, say camera-test.py containing:

import numpy as np
import cv2
cap = cv2.VideoCapture(0)
while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()
    # Our operations on the frame come here
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    # Display the resulting frame
    cv2.imshow('frame',frame)
    cv2.imshow('gray',gray)
    if cv2.waitKey(20) & 0xFF == ord('q'):
        break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

Now run:

C:\> python camera-test.py

You should see two images from your webcam--one in gray scale, one in color just like the one above, albeit with your face!.

To quit, hit the key q "on" the video window(s) to stop thecamera.

Intsalling opencv raspberry

https://www.alatortsev.com/2018/04/27/installing-opencv-on-raspberry-pi-3-b/

https://tutorials-raspberrypi.com/installing-opencv-on-the-raspberry-pi/

https://www.pyimagesearch.com/2017/09/04/raspbian-stretch-install-opencv-3-python-on-your-raspberry-pi/

Step 4: Installing ZBar (with Python Bindings) for Barcode Decoding

Installing ZBar for Ubuntu or Raspbian

Installing ZBar for Ubuntu can be accomplished with the following command:

$ sudo apt-get install libzbar0

Installing ZBar for macOS

Installing ZBar for macOSusing brew is equally as easy (assuming you have homebrew installed):

$ brew install zbar

Install pyzbar

Now that I have a Python 3 virtual environment named barcode on my machine, I activated the barcode environment (yours might have a different name) and installed pyzbar:

An OpenCV barcode and QR code scanner with ZBar

Shell

$ workon barcode$ pip install pyzbar

If you are not using a Pythonvirtual environment you can just do:

An OpenCV barcode and QR code scanner with ZBar

Python

$ pip install pyzbar install numpy $pip install numpy

Now match for OpenCV + ZBar + Python barcode scanner project! Press q to quit

zbar-test

# import the necessary packages
from imutils.video import VideoStream
from pyzbar import pyzbar
import argparse
import datetime
import imutils
import time
import cv2
 
# construct the argument parser and parse the arguments
ap = argparse.ArgumentParser()
ap.add_argument("-o", "--output", type=str, default="barcodes.csv",
	help="path to output CSV file containing barcodes")
args = vars(ap.parse_args())

# initialize the video stream and allow the camera sensor to warm up
print("[INFO] starting video stream...")
vs = VideoStream(src=0).start()
#vs = VideoStream(usePiCamera=True).start()
time.sleep(2.0)
 
# open the output CSV file for writing and initialize the set of
# barcodes found thus far
csv = open(args["output"], "w")
found = set()

# loop over the frames from the video stream
while True:
	# grab the frame from the threaded video stream and resize it to
	# have a maximum width of 400 pixels
	frame = vs.read()
	frame = imutils.resize(frame, width=400)
 
	# find the barcodes in the frame and decode each of the barcodes
	barcodes = pyzbar.decode(frame)
	# loop over the detected barcodes
	for barcode in barcodes:
		# extract the bounding box location of the barcode and draw
		# the bounding box surrounding the barcode on the image
		(x, y, w, h) = barcode.rect
		cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 0, 255), 2)
 
		# the barcode data is a bytes object so if we want to draw it
		# on our output image we need to convert it to a string first
		barcodeData = barcode.data.decode("utf-8")
		barcodeType = barcode.type
 
		# draw the barcode data and barcode type on the image
		text = "{} ({})".format(barcodeData, barcodeType)
		cv2.putText(frame, text, (x, y - 10),
			cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)
 
		# if the barcode text is currently not in our CSV file, write
		# the timestamp + barcode to disk and update the set
		if barcodeData not in found:
			csv.write("{},{}\n".format(datetime.datetime.now(),
				barcodeData))
			csv.flush()
			found.add(barcodeData)

			# show the output frame
	cv2.imshow("Barcode Scanner", frame)
	key = cv2.waitKey(1) & 0xFF
 
	# if the `q` key was pressed, break from the loop
	if key == ord("q"):
		break
 
# close the output CSV file do a bit of cleanup
print("[INFO] cleaning up...")
csv.close()
cv2.destroyAllWindows()
vs.stop()

Credits

Achraf Oukheir

8 projects • 14 followers

Embed the widget on your own site

QR Code Reader Decoder (Mac/Raspberry Pi)

QR Code Reader Decoder (Mac/Raspberry Pi)

Things used in this project

Hardware components

Software apps and online services

Story

Step 1: Setting Up and Using Python 3 Virtualenv on Mac

Step 2: Install OpenCV 3 for Python on Mac

Step 3: OpenCV and Python Webcam Quick Test

Step 4: Installing ZBar (with Python Bindings) for Barcode Decoding

Code

zbar-test

Credits

Achraf Oukheir

Comments

Related channels and tags