Picamera based QR code reader on a Raspberry Pi 3

This guide will show you how to create a QR code reader by using the zbarlight python library and picamera to take the picture. We will not be using open cv or any other image processing libraries.

What you'll need

• Raspberry Pi 2 / 3
• MicroSD Card with Raspbian on it (Tutorial)
• A picamera module (like this)
• Micro USB cable
• Keyboard, Mouse, Monitor
• HDMI cable for the monitor

If you are using the Raspberry Pi headless (Without a monitor, keyboard or mouse), You will need to connect to the internet using the ethernet port (for Raspberry Pi 2) or through the Wifi (on a Raspberry Pi 3 [Tutorial] ) and then you will have to use SSH to connect to your Raspberry Pi.

Installation process

Here onwards everything will be on the terminals. Press CTRL + ALT + T to open up the terminals.

STEP 1 - Initial installations

The apt-get must always be kept updated.

sudo apt-get update -y && sudo apt-get upgrade -y

This will take some time depending on your internet speed and also the amount of package's that are installed onto your Raspberry Pi's OS.

STEP 2 - Installing and running picamera

You will need to install this to access the picamera hardware python. To install this you will need to use apt-get.

sudo apt-get install python-picamera python3-picamera

This will install picamera module for using Picamera hardware from python

STEP 3 - Installing zbarlight

This is the brain of our QR code reader. This library helps us to decode an image into their basic codes.

First we have to install the following:

sudo apt-get install libzbar0 libzbar-dev

Then we have to install the zbarlight

sudo pip install zbarlight

After this you can run the reader.py python program that I have written to test if it works. It will first save capture 'foo.jpg' using picamera and then will attempt to read QR code from the same image. This reader.py program does the following:

• Runs get_image function to capture 'foo.jpg' using PiCamera
• Checks if it has QR Codes
• Prints qr code information if available
• If there is no QR code present after we run it through zbarlight then 'No QR code found' message will be printed

If you want to run the code enter

sudo python reader.py

Credits:
Major thanks to the original contributor of this:
https://github.com/rijinmk

Reference:
https://github.com/rijinmk/code-qr-code-reader-rpi3