A Python script for batch converting images and PDFs into web-optimized formats with WordPress-friendly filenames.

• Multi-format Support: Convert TIF, JPG, PNG, BMP, GIF, and PDF files
• Modern Output Formats: AVIF, WebP, PNG, or JPG
• WordPress-Optimized Naming: Automatic SEO-friendly slug generation
• Filename Prefix Support: Optional prefix for organized file naming (e.g., abc123-)
• Smart Output Directory: Defaults to output-web subfolder in source directory
• Flexible File Overwrite: Choose to overwrite existing files or create new ones with incremental naming
• Advanced Filtering: Exclude directories by pattern and filter files by name
• Smart Image Processing: Auto-resize, EXIF orientation correction, color mode handling
• Large Image Support: Handles high-resolution images up to 300 megapixels
• PDF to Image: Convert multi-page PDFs to individual images
• Collision-Safe: Automatic handling of duplicate filenames
• Quality Control: Configurable compression and quality settings

pip install Pillow

For AVIF support:

pip install pillow-avif-plugin

For PDF conversion:

pip install pymupdf

Run the script interactively:

python batch_convert_assets.py

You'll be prompted for:

1. Source Directory: Path to input files (default: current directory)
2. Output Directory: Path for converted files (default: <source-dir>/output-web)
3. Filename Prefix: Optional prefix for all output files (e.g., ABC123)
4. Overwrite Mode: Choose to overwrite existing files or create new ones with index
5. File Filtering: Optionally enable advanced filtering
   • Directory Exclusion: Skip directories containing a pattern (e.g., excl)
   • Filename Pattern: Only process files containing a pattern (e.g., _web)
6. File Extensions: Comma-separated list (default: tif,jpg,jpeg,png,pdf)
7. Target Format: Output format - avif, webp, png, or jpg (default: webp)
8. Target Width: Maximum width in pixels (default: 1920)
9. Quality: Compression quality 0-100 (default: 80)
10. PDF Zoom: Rendering resolution for PDFs (default: 2.0 ≈ 144 DPI)

=== Batch-Konverter: TIF/JPG/PNG/PDF -> AVIF/WEBP/PNG/JPG (WordPress-optimierte Namen) ===

Quellordner eingeben [.]: /path/to/images
Zielordner eingeben [/path/to/images/output-web]:
Dateinamen-Prefix (z.B. ABC123, optional - Enter für keinen) []: PRJ001
  → Normalisierter Prefix: 'prj001-'
Existierende Dateien im Zielordner überschreiben? (y/n) [n]: n
  → Bei Namenskollisionen werden neue Dateien mit Index erstellt (-001, -002, ...)
Datei-Filter aktivieren? (y/n) [n]: y
Verzeichnisse ausschließen mit Muster [...] []: backup
  → Verzeichnisse mit 'backup' werden übersprungen
Nur Dateien verarbeiten mit Muster im Namen [...] []: _web
  → Nur Dateien mit '_web' im Namen werden verarbeitet
Dateimuster (Komma-getrennt), z.B. tif,jpg,png,pdf [tif,jpg,jpeg,png,pdf]: png,jpg
Zielformat (avif/webp/png/jpg) [webp]: webp
Ziel-Bildbreite in Pixel (Höhe proportional) [1920]: 1920
Qualität (0-100, höher = besser; PNG ignoriert es) [80]: 85
PDF-Render-Zoom (1.0 ≈ 72 DPI, 2.0 ≈ 144 DPI) [2.0]: 2.0

Starte Verarbeitung …

The script automatically converts filenames to WordPress-compatible slugs:

Transformations:

• German umlauts: ä→ae, ö→oe, ü→ue, ß→ss
• Removes diacritics and special characters
• Converts to lowercase
• Replaces spaces and special chars with hyphens
• Optionally adds prefix at the beginning (normalized to lowercase, alphanumeric only)
• Handles duplicate names with -001, -002 suffixes

Prefix Feature:

• Enter a prefix like ABC123 or Project-42 when prompted
• Normalized to: abc123- or project42-
• Smart detection: won't duplicate if filename already has the prefix
• Press Enter to skip prefix (optional)

Choose how to handle existing files in the output directory:

Overwrite Mode (y):

• Existing files are replaced with newly converted versions
• Useful for refreshing an entire output directory
• Example: photo.webp exists → overwrites photo.webp

Keep Mode (n - default):

• Creates new files with incremental suffixes on name collision
• Preserves existing files in the output directory
• Example: photo.webp exists → creates photo-001.webp
• Further collisions create photo-002.webp, photo-003.webp, etc.

Optional filtering system to control which files are processed:

Directory Exclusion:

• Skip directories containing a specific pattern in their path
• Case-insensitive matching
• Example: Pattern backup skips /photos/backup/, /backup-2024/, etc.
• Press Enter to skip directory filtering (processes all directories)

Filename Pattern:

• Only process files containing a specific pattern in their name
• Case-insensitive matching
• Example: Pattern _web only processes photo_web.jpg, image_web_final.png
• Press Enter to skip filename filtering (processes all matching files)

• Auto-resize: Images wider than target width are scaled down proportionally
• EXIF correction: Automatically fixes image orientation based on EXIF data
• Color mode handling: Converts CMYK to RGB, handles transparency appropriately
• Format-specific optimization:
  • JPG: Progressive encoding, 4:2:0 chroma subsampling, optimize flag
  • PNG: Compression level 6
  • WebP: Method 6 for better compression
  • AVIF: Quality-based encoding

• Each PDF page becomes a separate image file
• Naming convention: filename-p001.webp, filename-p002.webp, etc.
• Configurable rendering resolution (zoom factor)
• Supports both RGB and RGBA rendering

All converted files are placed in the output directory with flat structure (no subdirectories), making them easy to bulk upload to WordPress media library.

The script will:

• Skip unsupported file types
• Continue processing if individual files fail
• Display error messages for failed conversions
• Warn if optional dependencies are missing

• Images: .jpg, .jpeg, .png, .tif, .tiff, .bmp, .gif
• Documents: .pdf (requires PyMuPDF)

• AVIF: Modern, highly compressed (requires pillow-avif-plugin)
• WebP: Modern, good browser support
• PNG: Lossless, best for graphics with transparency
• JPG: Lossy, universal compatibility

• Larger zoom values for PDFs result in better quality but larger files
• Quality 80-85 offers good balance for WebP/AVIF
• Use WebP for broad compatibility, AVIF for maximum compression

This script is provided as-is for personal and commercial use.

Install Pillow: pip install Pillow

Install AVIF plugin: pip install pillow-avif-plugin

Install PyMuPDF: pip install pymupdf

The script automatically handles EXIF orientation. If images still appear rotated, the source file may have incorrect metadata.

Increase the quality parameter (recommended: 85-95 for important images)

The script handles images up to 300 megapixels. If you need to process even larger images, this limit can be adjusted in the code.

Feel free to modify and extend this script for your needs. Common enhancements:

• Add command-line argument support
• Implement parallel processing for faster conversion
• Add watermarking capabilities
• Support additional metadata preservation