RTesseract

Ruby library for working with the Tesseract OCR.

Installation

Check if tesseract ocr programs are installed:

$ tesseract --version

If not, you can install them with a command like:

$ apt install tesseract-ocr

$ brew install tesseract

or for Heroku 22 to add the buildpack https://github.com/pathwaysmedical/heroku-buildpack-tesseract

Add this line to your application's Gemfile:

gem 'rtesseract'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rtesseract

Usage

It's very simple to use rtesseract.

Convert image to string

  image = RTesseract.new("my_image.jpg")
  image.to_s # Getting the value

Convert image to searchable PDF

  image = RTesseract.new("my_image.jpg")
  image.to_pdf  # Getting open file of pdf

Convert image to TSV

  image = RTesseract.new("my_image.jpg")
  image.to_tsv  # Getting open file of tsv

This will preserve the image colors, pictures and structure in the generated pdf.

Options

Language

    RTesseract.new('test.jpg', lang: 'deu')

eng - English
deu - German
deu-f - German fraktur
fra - French
ita - Italian
nld - Dutch
por - Portuguese
spa - Spanish
vie - Vietnamese
or any other supported by tesseract.

Note: Make sure you have installed the language to tesseract

Other options

  RTesseract.new('test.jpg', config_file: :digits)  # Only digit recognition

  RTesseract.new('test.jpg', config_file: 'digits quiet')

BOUNDING BOX: TO GET WORDS WITH THEIR POSITIONS

  RTesseract.new('test_words.png').to_box
  => [
    { :word => 'If', :confidence=>89, :x_start=>52, :y_start=>13, :x_end=>63, :y_end=>27},
    { :word => 'you', :confidence=>96, :x_start=>69, :y_start=>17, :x_end=>100, :y_end=>31},
    { :word => 'are', :confidence=>92, :x_start=>108, :y_start=>17, :x_end=>136, :y_end=>27},
    { :word => 'a', :confidence=>92, :x_start=>133, :y_start=>8, :x_end=>147, :y_end=>35},
    { :word => 'friend,', :confidence=>95, :x_start=>158, :y_start=>13, :x_end=>214, :y_end=>29},
    { :word => 'you', :confidence=>96, :x_start=>51, :y_start=>39, :x_end=>82, :y_end=>53},
    { :word => 'speak', :confidence=>96, :x_start=>90, :y_start=>35, :x_end=>140, :y_end=>53},
    { :word => 'the', :confidence=>96, :x_start=>146, :y_start=>35, :x_end=>174, :y_end=>49},
    { :word => 'password,', :confidence=>96, :x_start=>182, :y_start=>35, :x_end=>267, :y_end=>53},
    { :word => 'and', :confidence=>96, :x_start=>51, :y_start=>57, :x_end=>81, :y_end=>71},
    { :word => 'the', :confidence=>96, :x_start=>89, :y_start=>57, :x_end=>117, :y_end=>71},
    { :word => 'doors', :confidence=>96, :x_start=>124, :y_start=>57, :x_end=>172, :y_end=>71},
    { :word => 'will', :confidence=>96, :x_start=>180, :y_start=>57, :x_end=>208, :y_end=>71},
    { :word => 'open.', :confidence=>96, :x_start=>216, :y_start=>61, :x_end=>263, :y_end=>75}
  ]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/dannnylo/rtesseract. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Rtesseract project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.