EDocman Thumbnail Generator Plugin
Overview
The EDocman Thumbnail Generator plugin automatically generates thumbnail images from uploaded PDF documents.
Plugin Group: edocman
Purpose: Auto-generate PDF thumbnails on document upload
Requires: PHP GD or ImageMagick library
Configuration
| Parameter | Description |
|---|
| PDF Page for Thumbnail |
Which page to extract for thumbnail generation (typically page 1 for cover page) |
| Enable Watermark |
Add text watermark overlay on generated thumbnail |
| Watermark Text |
Text to display as watermark (e.g., "Preview", "Sample", company name) |
| Watermark Font Size |
Font size for watermark text in pixels |
How It Works
- User uploads PDF document in admin or frontend
- Plugin detects PDF file type
- Extracts specified page as image
- Resizes to configured thumbnail dimensions (from component configuration)
- Applies watermark if enabled
- Saves thumbnail to media folder
- Associates thumbnail with document automatically
Features
- Automatic Generation: No manual thumbnail creation needed
- Configurable Page Selection: Use any page from PDF as thumbnail
- Watermark Support: Brand or protect thumbnails with text overlay
- Standard Integration: Uses component thumbnail size settings
- Performance Optimized: Generates thumbnail once on upload
System Requirements
- PHP GD library with PDF support OR
- ImageMagick extension installed on server
- Sufficient PHP memory limit for PDF processing (128MB+ recommended)
Usage
- Navigate to Extensions → Plugins in Joomla admin
- Search for "EDocman Thumbnail Generator"
- Enable the plugin
- Click plugin name to configure
- Set PDF page and watermark options
- Save configuration
- Upload PDF documents - thumbnails generate automatically
Use Cases
- Document Libraries: Automatic visual previews for all PDFs
- Report Repositories: Show report cover pages
- eBook Collections: Display book covers automatically
- Brochure Downloads: Visual identification of marketing materials
- Branded Previews: Watermark thumbnails with company logo text
Troubleshooting
Thumbnails Not Generating:
- Verify PHP GD or ImageMagick is installed: Check
phpinfo()
- Increase PHP memory limit in php.ini:
memory_limit = 256M
- Check PDF file is not corrupted
- Verify write permissions on media folder
Poor Quality Thumbnails:
- Increase thumbnail dimensions in component configuration
- Use higher quality source PDFs
- Check PHP GD configuration for JPEG quality settings
Watermark Not Appearing:
- Ensure watermark is enabled in plugin settings
- Check watermark text is not empty
- Verify font size is appropriate for thumbnail dimensions
Tips
- Use page 1 for most documents (cover page)
- Keep watermark text short for readability
- Test watermark font size with different thumbnail dimensions
- Consider disabling watermark for public documents
- Use watermark for preview/sample indicators
- Combine with manual thumbnail override when needed
Updated: January 2026