generate_qr_code.rb

require 'pry'
require 'rqrcode'

qrcode = RQRCode::QRCode.new('https://cs125.cs.illinois.edu')

png = qrcode.as_png(
  bit_depth: 1,
  border_modules: 4,
  color_mode: ChunkyPNG::COLOR_GRAYSCALE,
  color: 'black',
  file: nil,
  fill: 'white',
  module_px_size: 6,
  resize_exactly_to: false,
  resize_gte_to: false,
  size: 600
)

logo_size = 200
cs125_png = ChunkyPNG::Image.from_file('cs125.png')
cs125_png = cs125_png.resize(logo_size, logo_size)

png = png.compose(cs125_png, png.width/2 - logo_size/2, png.height/2 - logo_size/2)

# binding.pry

IO.write("/tmp/github-qrcode.png", png.to_s)

Quick and dirty approach but considering how noisy QR codes tend to be works decently well actually. Make sure to test your code before running with it, and perhaps then you can run a loop with it till it works. All this is pure ruby so

$ gem install rqrcode
$ ruby generate_qr_code.rb

Adapted parts from the rqrcode docs on RDoc, more helpful information available there.

MIT License