Read images from a webcam. OCR any text and write it to stdout.

ocr.rb

require 'hornetseye_v4l2'
require 'hornetseye_xorg'
require 'hornetseye_rmagick'
require 'tesseract'

include Hornetseye

camera = V4L2Input.new
image = X11Display.show { camera.read }
image.to_ubytergb.save_ubytergb 'snapshot.png'

e = Tesseract::Engine.new do |e|
  e.language = :eng
  e.blacklist = '|'
end

puts e.text_for('snapshot.png').strip

This only works on Linux (v4l2 is "video for Linux 2"). My webcam's resolution is also not great, so it can't seem to read things like receipts well (yet -- I've tried basically nothing in terms of preprocessing.)

Also there was a bunch of setup I had to do to get hornetseye installing properly: mostly apt stuff, but I also had to rebuild Ruby with CONFIGURE_OPTS=--enable-shared rbenv install 2.1.1.