PDF OCR

A lightweight Ruby gem for extracting text from PDFs, including scanned PDFs using OCR.

This gem supports:

• PDFs with readable text
• Scanned PDFs using Tesseract OCR
• File objects, file paths, StringIO, and Rails/ActiveStorage uploads
• Fully Rails-independent

• Detect if PDF is scanned or text-based
• Extract text from normal PDFs using PDF::Reader
• Extract text from scanned PDFs using RTesseract and MiniMagick
• Automatic cleanup of temporary images

Add this line to your application's Gemfile:

gem 'pdf_ocr'

Or install directly:

gem install pdf_ocr

• PDF::Reader

• RTesseract

• MiniMagick

• Tesseract OCR (system-level executable)

• pdftoppm from Poppler utils (for converting PDF pages to images)

require 'pdf_ocr'
require 'stringio'

# From a File object
file = File.open("path/to/document.pdf")
result = Ocr::DataExtractor.new(file).call
puts result["raw_text"] if result["success"]

# From a file path string
result = Ocr::DataExtractor.new("path/to/document.pdf").call

# From a StringIO object (in-memory PDF)
pdf_data = StringIO.new(File.read("path/to/document.pdf"))
result = Ocr::DataExtractor.new(pdf_data).call

{
  "success" => true,
  "raw_text" => "Extracted text content from PDF ..."
}

• If OCR fails for a scanned PDF:

{
  "success" => false,
  "message" => "Unable to extract text using OCR"
}

1. Ensure Tesseract OCR is installed on your system:

# Ubuntu/Debian
sudo apt install tesseract-ocr

# MacOS (with Homebrew)
brew install tesseract

2. Ensure pdftoppm is installed (for PDF-to-image conversion):

# Ubuntu/Debian
sudo apt install poppler-utils

# MacOS (with Homebrew)
brew install poppler

3. This gem does not require Rails, but it will work with Rails ActiveStorage objects that respond to .open.

bundle install
bundle exec rspec

• PDFs with selectable text

• Scanned PDFs

• Malformed PDFs (fallback to OCR)

• Fork the repository

• Create your feature branch (git checkout -b your-feature)

• Commit your changes (git commit -am 'Add new feature')

• Push to the branch (git push origin your-feature)

• Open a Pull Request

Ravi Shankar Singhal
Senior Backend Developer — Ruby on Rails
📧 ravi.singhal2308@gmail.com

🌐 https://github.com/RaviShankarSinghal

MIT License © RaviShankarSinghal

This version includes:

• Version and build badges (replace with your repo info)
• Clear installation instructions
• Usage examples for File, path, and StringIO
• System dependencies
• Test instructions
• Contributing guidelines
• The gem is available as open source under the terms of the MIT License.