PDF to JPEG Converter and Image Processing Tools

A collection of bash scripts for converting PDF files to JPEG images, merging multiple images, and compressing the results. This project is particularly useful for creating long vertical images from multi-page PDF documents.

🚀 Features

• PDF to JPEG Conversion: Convert PDF pages to individual JPEG images
• Image Merging: Combine multiple JPEG images into a single vertical image
• Image Compression: Reduce file sizes while maintaining quality
• Batch Processing: Handle multiple pages automatically
• Flexible Workflow: Use scripts independently or in combination

📁 Project Structure

DEMO1/
├── README.md           # This documentation file
├── convert.sh          # Main script: PDF → JPEG pages → merged image
├── join.sh             # Merge existing JPEG images vertically
├── compress.sh         # Compress images to reduce file size
├── assets/             # Input files directory
│   ├── DEMO1.pdf       # Sample PDF file
│   ├── DEMO1_page-*.jpg # Pre-converted pages (if available)
│   └── DEMO2.pdf       # Additional PDF files
├── process/            # Temporary directory for page conversion
├── output/             # Final output directory
│   └── merged.jpg      # Result of conversion/merging
├── page-*.jpg          # Individual page images (generated)
└── compress.jpg        # Compressed version (if created)

🛠️ Prerequisites

Before using these scripts, ensure you have the required dependencies installed:

Ubuntu/Debian:

sudo apt update
sudo apt install poppler-utils imagemagick

CentOS/RHEL/Fedora:

# For CentOS/RHEL
sudo yum install poppler-utils ImageMagick

# For Fedora
sudo dnf install poppler-utils ImageMagick

macOS:

brew install poppler imagemagick

📖 Usage

Method 1: Complete PDF Processing (Recommended)

Convert a PDF file to individual pages and merge them into a single image:

# Make the script executable
chmod +x convert.sh

# Run the conversion process
./convert.sh

What it does:

1. Converts ./assets/DEMO1.pdf to individual JPEG pages in ./process/
2. Merges all pages into ./output/merged.jpg

Method 2: Join Existing Images

If you already have JPEG images and want to merge them:

# Make the script executable
chmod +x join.sh

# Run from directory containing JPEG files
./join.sh

What it does:

• Merges all .jpg files in the current directory
• Creates output.jpg with vertically stacked images

Method 3: Compress Images

Reduce file size of your merged images:

# Make the script executable
chmod +x compress.sh

# Run compression (requires output.jpg to exist)
./compress.sh

What it does:

• Compresses output.jpg with 70% quality
• Creates compress.jpg with reduced file size
• Shows file size comparison

🔧 Customization

Changing Input Files

To process a different PDF file, modify convert.sh:

# Change this line in convert.sh:
pdftoppm -jpeg ./assets/YOUR_FILE.pdf ./process/page

Adjusting Image Quality

To change compression quality, modify compress.sh:

# Change quality value (1-100, where 100 is best quality):
convert output.jpg -quality 85 compress.jpg

Output Format Options

You can modify the scripts to output different formats:

# For PNG output (in convert.sh):
pdftoppm -png ./assets/DEMO1.pdf ./process/page

# For horizontal merging instead of vertical:
convert +append ./process/page-*.jpg ./output/merged.jpg

📋 Script Details

convert.sh

• Purpose: Main conversion script
• Input: PDF file in ./assets/
• Output: Merged JPEG in ./output/
• Process: PDF → Individual pages → Merged image

join.sh

• Purpose: Merge existing JPEG images
• Input: JPEG files in current directory
• Output: output.jpg
• Use case: When you already have individual images

compress.sh

• Purpose: Reduce image file size
• Input: output.jpg
• Output: compress.jpg
• Quality: 70% (adjustable)

🐛 Troubleshooting

Common Issues

1. "Command not found" errors

   # Install missing dependencies
   sudo apt install poppler-utils imagemagick

2. Permission denied

   # Make scripts executable
   chmod +x *.sh

3. "No such file or directory"

   • Ensure your PDF file is in the ./assets/ directory
   • Check that the filename matches what's specified in the script

4. ImageMagick policy errors

   # If you get PDF policy errors, you may need to modify ImageMagick policy
   sudo vim /etc/ImageMagick-6/policy.xml
   # Comment out or modify the PDF policy line

Debugging

Enable verbose output by adding -v flag to bash:

bash -v convert.sh

📊 Performance Tips

• Large PDFs: For very large PDF files, consider processing in batches
• Memory Usage: Monitor system memory when processing high-resolution PDFs
• Storage: Ensure adequate disk space for temporary files in ./process/

🔄 Workflow Examples

Basic Workflow

# 1. Place your PDF in assets/
cp your_document.pdf assets/

# 2. Update convert.sh to use your PDF name
# 3. Run conversion
./convert.sh

# 4. Optional: Compress the result
./compress.sh

Batch Processing Multiple PDFs

# Process multiple PDFs (manual approach)
for pdf in assets/*.pdf; do
    filename=$(basename "$pdf" .pdf)
    pdftoppm -jpeg "$pdf" "process/${filename}-page"
    convert -append "process/${filename}-page"*.jpg "output/${filename}-merged.jpg"
done

📝 License

This project is open source and available under the MIT License.

🤝 Contributing

Feel free to submit issues, fork the repository, and create pull requests for any improvements.

📞 Support

If you encounter any issues or have questions:

1. Check the troubleshooting section above
2. Ensure all dependencies are properly installed
3. Verify file paths and permissions
4. Create an issue in the repository

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Created on: July 1, 2025
Version: 1.0.0