Pillow Image Processing Skill

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This skill provides comprehensive image processing capabilities through executable scripts and reference documentation for Pillow (PIL).

When to Use This Skill

Activate this skill when the user requests:

• Image editing operations (resize, crop, rotate, color adjustments)
• Batch processing multiple images
• Adding watermarks (text or image)
• Image format conversions
• Extracting image metadata or EXIF data
• Applying filters or effects
• Creating thumbnails

Core Capabilities

1. Image Editor (scripts/image_editor.py)

Edit single images with various operations:

Usage:

python scripts/image_editor.py input.jpg output.jpg [options]

Options:

• --width WIDTH / --height HEIGHT: Resize dimensions
• --no-aspect: Ignore aspect ratio when resizing
• --crop X Y WIDTH HEIGHT: Crop rectangle
• --rotate DEGREES: Rotate image
• --flip {horizontal,vertical}: Flip image
• --brightness FACTOR: Adjust brightness (0.0-2.0)
• --contrast FACTOR: Adjust contrast (0.0-2.0)
• --color FACTOR: Adjust color saturation (0.0-2.0)
• --sharpness FACTOR: Adjust sharpness (0.0-2.0)
• --filter {blur,contour,detail,edge_enhance,emboss,sharpen,smooth}: Apply filter
• --format FORMAT: Output format (JPEG, PNG, etc.)
• --quality QUALITY: JPEG quality (1-100)

Examples:

# Resize maintaining aspect ratio
python scripts/image_editor.py photo.jpg resized.jpg --width 800

# Multiple operations
python scripts/image_editor.py input.jpg output.jpg \
    --crop 100 100 800 600 \
    --rotate 90 \
    --brightness 1.2 \
    --sharpen 1.5

2. Batch Processor (scripts/batch_processor.py)

Process multiple images in parallel:

Usage:

python scripts/batch_processor.py input_dir output_dir [options]

Options:

• --pattern PATTERN: File pattern (e.g., *.jpg)
• --resize WIDTH HEIGHT: Resize all images
• --thumbnail MAX_W MAX_H: Create thumbnails (maintains aspect)
• --grayscale: Convert to grayscale
• --brightness FACTOR: Adjust brightness
• --format FORMAT: Convert format
• --quality QUALITY: JPEG quality
• --workers N: Number of parallel workers (default: 4)

Examples:

# Create thumbnails
python scripts/batch_processor.py ./photos ./thumbs --thumbnail 300 300

# Batch convert and resize
python scripts/batch_processor.py ./raw ./processed \
    --resize 1920 1080 \
    --format JPEG \
    --quality 90

3. Watermark Tool (scripts/watermark.py)

Add text or image watermarks:

Usage:

python scripts/watermark.py input.jpg output.jpg --text "TEXT" [options]
python scripts/watermark.py input.jpg output.jpg --image logo.png [options]

Common Options:

• --position {top-left,top-right,bottom-left,bottom-right,center}: Position
• --opacity 0-255: Transparency level
• --margin PIXELS: Margin from edge

Text Options:

• --font-size SIZE: Font size
• --color COLOR: Text color (white/black/red/etc)

Image Options:

• --scale RATIO: Watermark scale (0.0-1.0)

Examples:

# Text watermark
python scripts/watermark.py photo.jpg marked.jpg \
    --text "© 2026 Company" \
    --position bottom-right \
    --opacity 128

# Logo watermark
python scripts/watermark.py image.jpg output.jpg \
    --image logo.png \
    --scale 0.2 \
    --position top-left

4. Image Info (scripts/image_info.py)

Extract image metadata and properties:

Usage:

python scripts/image_info.py image.jpg [options]

Options:

• --format {text,json}: Output format
• --output FILE: Save to file

Provides:

• File information (size, path)
• Image properties (dimensions, format, mode)
• Color information (bands, palette)
• EXIF data (if available)
• Metadata

Example:

# Display info
python scripts/image_info.py photo.jpg

# Save as JSON
python scripts/image_info.py photo.jpg -o info.json --format json

Reference Documentation

references/common_operations.md

Comprehensive Pillow reference covering:

• Opening and saving images
• Resizing and cropping
• Rotation and flipping
• Color adjustments and enhancements
• Filters and effects
• Drawing on images
• Image composition
• Working with channels
• EXIF data handling
• Performance tips

When to use: When Claude needs specific Pillow syntax or operation patterns.

references/best_practices.md

Best practices guide covering:

• Format selection (JPEG vs PNG vs WebP)
• Resizing strategies
• Color mode conversion
• Memory management
• Watermarking strategies
• Filter application
• Optimization techniques
• Error handling patterns
• Common workflows

When to use: When designing image processing workflows or optimizing performance.

Workflow Guidelines

Step 1: Analyze Requirements

• What format is the input image?
• What operations are needed?
• Is it a single image or batch?
• Are there quality requirements?

Step 2: Choose the Right Tool

• Single image edit → image_editor.py
• Multiple images → batch_processor.py
• Add watermark → watermark.py
• Need info → image_info.py

Step 3: Plan Operations

• Apply operations in logical order
• Consider quality vs file size tradeoffs
• Validate input requirements

Step 4: Execute and Validate

• Run the script with appropriate options
• Check output quality
• Verify file sizes and formats

Common Patterns

Pattern 1: Web Image Optimization

# Resize and optimize for web
python scripts/image_editor.py large.jpg web.jpg \
    --width 1200 \
    --quality 85 \
    --format JPEG

Pattern 2: Create Image Gallery

# Generate thumbnails
python scripts/batch_processor.py ./originals ./gallery \
    --thumbnail 400 400 \
    --format JPEG \
    --quality 90

Pattern 3: Brand Images with Watermark

# Add company logo
python scripts/watermark.py product.jpg branded.jpg \
    --image company_logo.png \
    --position bottom-right \
    --scale 0.15 \
    --opacity 180

Pattern 4: Batch Format Conversion

# Convert PNG to JPEG
python scripts/batch_processor.py ./pngs ./jpegs \
    --format JPEG \
    --quality 95

Dependencies

pip install Pillow

Tips for Effective Use

1. Preserve originals: Never overwrite source images
2. Use appropriate formats: JPEG for photos, PNG for graphics
3. Optimize quality: Balance quality and file size
4. Batch operations: Use batch processor for multiple images
5. Check references: Consult reference docs for advanced operations
6. Validate inputs: Check image format and size before processing
7. Test first: Try operations on one image before batch processing

Limitations

• Limited to 2D image processing (no video)
• Some EXIF data may not be preserved in all formats
• Font availability may vary by system
• Very large images may require significant memory
• Advanced photo editing (layers, masks) requires specialized tools

Troubleshooting

Import errors: Ensure Pillow is installed (pip install Pillow) Font not found: Watermark script falls back to default font Memory errors: Process large images in smaller batches Format errors: Check input image format compatibility RGBA to JPEG: Script automatically handles RGBA→RGB conversion

For detailed operations and troubleshooting, always refer to references/common_operations.md and references/best_practices.md.