OCR engine module

ocr_helper.rb

require 'rtesseract'
require 'RMagick'
require 'tesseract'

module OCRHelper

  def toast?(error_msg, screens:5, delay:nil, pre_pause:nil)
    # Thread.new{take_multiple_screens(6, 0.3, 0.5)}
    take_multiple_screens(screens, delay, pre_pause)
    recognize_multiple_screens(screens, error_msg)
  end

  def text_position(text)
    text = text.to_s unless text.is_a?(String)
    pic_location = "#{Dir::pwd}/gen/screenshots/txt_#{text.gsub(' ', '_')}.png"
    $driver.screenshot(pic_location)
    img = process_image(pic_location)
    img2 = img.write("#{Dir::pwd}/gen/screenshots/changed.png")

    e = ocr_proc(img2)
    words = ""
    box = e.each_word do |w|
      words << (' ' + w.to_s)
      if w.to_s.include?(text)
        break w.bounding_box
      end
    end
    debug words

    x = (box.x + box.width / 2) / 3
    y = (box.y + box.height / 2)/ 3
    {x: x, y: y}
  end

# take multiple screenshots in order to catch the error on the screen
  def take_multiple_screens(circles, delay, pre_pause)
    sleep(pre_pause) unless pre_pause.nil?
    circles.times do|index|
      debug "Taking screenshot # #{index + 1}"
      $driver.screenshot("#{Dir::pwd}/gen/screenshots/rec_#{index}.png")
      sleep(delay) unless delay.nil?
    end
  end

  def recognize_multiple_screens(circles, text)
    circles.times do |index|
      debug "Checking: #{Dir::pwd}/gen/screenshots/rec_#{index}.png"
      rec_text = recognize_text_on_pic("#{Dir::pwd}/gen/screenshots/rec_#{index}.png")
      return true if rec_text.include?(text)
    end
     false
  end

  #by default RTesseract gem is used here
  def recognize_text_on_pic(pic_location=nil)
    img = process_image(pic_location)
    tess = RTesseract.new(img, lang: 'eng')
    debug ocr_proc(img).text if $DEBUG

    rec_text = tess.to_s # recognize
    debug rec_text.gsub(/\n/, '\n')
      # debug("----- ----- Recognized text ----- -----\n")
      # debug(rec_text)
      # debug("\n----- ----- ----- ----- ----- -----")
    rec_text
  end

  def process_image(pic_location)
    img = Magick::Image.read(pic_location).first
    #img = img.quantize(256,Magick::GRAYColorspace)
    img.contrast.normalize.negate.posterize(3).adaptive_resize(3)
  end

  #tesseract-ocr gem is used here (could get better results)
  def ocr_proc(img)
    Tesseract::Engine.new {|e|
      e.language  = :eng
      #e.blacklist = '|'
      e.image = img
    }
  end
end


module BasePage
  class << self
    def tap_on_text(text)
      pos = OCRHelper.text_position(text)
      tap_on(pos) #pos[:x], pos[:y]
    end

    def tap_on(hash) # x_cord, y_cord
     Appium::TouchAction.new.tap(hash).release.perform # x: x_cord, y: y_cord
    end
  end
end

BasePage.tap_on_text('some text')