Barcode Reader

A Ruby application for reading barcodes from PDF files. The application converts PDF pages to images, enhances them for better barcode detection, and extracts barcode data.

System Requirements

Ruby Version

• Ruby 2.6.6 or higher

System Dependencies

Only zbar-tools needs to be installed as a system package. ImageMagick is handled through the mini_magick gem.

Linux (Ubuntu/Debian)

sudo apt-get update
sudo apt-get install zbar-tools

Linux (RHEL/CentOS/Fedora)

sudo dnf install zbar    # Use 'yum' instead of 'dnf' for older versions

macOS

brew install zbar

# If you don't have Homebrew installed
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Ruby Dependencies

1. First, install bundler if you haven't:

gem install bundler

2. Install required gems:

bundle install

Key gems used:

• pdf-reader - For reading and processing PDF files
• mini_magick - For image processing and enhancement
• Standard library: tempfile, fileutils

Usage

Basic Usage

To scan a PDF file for barcodes:

cd test_files
bundle exec ruby barcode_reader.rb path/to/your/file.pdf

Process Flow

1. PDF Processing:

   • Reads PDF using pdf-reader
   • Processes first two pages only
   • Converts pages to high-resolution PNG (600 DPI)

2. Image Enhancement (using mini_magick):

   • Converts to grayscale
   • Auto-levels and normalizes
   • Enhances contrast
   • Applies sharpening

3. Barcode Detection:

   • Uses zbarimg command-line tool
   • Extracts barcode data
   • Parses into CRN and Amount

Output Format

The script outputs:

1. Raw barcode data (e.g., *29581200051216188000014453)
2. Parsed data:
   • Customer Reference Number (CRN)
   • Payment Amount (formatted as currency)

Troubleshooting

PDF Processing Issues

If you encounter PDF processing issues:

1. Ensure PDF is not password-protected
2. Check PDF is not corrupted
3. Try with a different PDF to isolate the issue

Barcode Detection Issues

If barcode is not being detected:

1. Ensure PDF quality is good
2. Check if barcode is visible and not distorted
3. Try adjusting image enhancement parameters in the code

System Dependencies

If you get command not found errors:

1. Verify zbar-tools is installed: which zbarimg
2. Check system PATH includes the necessary directories
3. Try reinstalling the package