Image Optimization Skill

Mac-only skill for lossless image optimization using ImageOptim + optional ImageMagick pre-processing.

Trigger

• User mentions "ImageOptim" with image files
• User asks to "optimize images"
• User provides images needing compression/metadata removal

Core Command

/Applications/ImageOptim.app/Contents/MacOS/ImageOptim <files...>

Blocks until complete. No flags allowed (args must not start with -).

Protocol

Step 1: Validate

# Check ImageOptim exists
test -x /Applications/ImageOptim.app/Contents/MacOS/ImageOptim || echo "ImageOptim not installed"

Step 2: Pre-process (Optional)

Use ImageMagick ONLY if:

• Image exceeds 4000px in any dimension (resize for web)
• Image is in non-web format (convert to PNG/JPG/WebP)
• User explicitly requests resize/convert

# Resize if >4000px (preserves aspect ratio)
magick input.jpg -resize '4000x4000>' output.jpg

# Convert format
magick input.bmp output.png

# Strip metadata (alternative to ImageOptim)
magick input.jpg -strip output.jpg

Step 3: Optimize

# Single file
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim image.png

# Multiple files
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim *.png *.jpg

# Directory (all images)
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim ./images/

Step 4: Report

# Show size reduction
ls -lh <files>

Decision Tree

Image provided?
├── NO → Ask user for file path
└── YES → Check dimensions
    ├── >4000px → magick resize first
    └── ≤4000px → Direct to ImageOptim
        └── Run ImageOptim
            └── Report size savings

Examples

Basic optimization

/Applications/ImageOptim.app/Contents/MacOS/ImageOptim screenshot.png

Batch directory

/Applications/ImageOptim.app/Contents/MacOS/ImageOptim ./assets/images/

Resize then optimize

magick hero.jpg -resize '2000x2000>' hero.jpg && \
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim hero.jpg

Convert and optimize

magick logo.bmp logo.png && \
/Applications/ImageOptim.app/Contents/MacOS/ImageOptim logo.png

What ImageOptim Does

• Lossless compression (PNG, JPEG, GIF, SVG)
• Metadata removal (EXIF, GPS, camera info)
• Color profile optimization
• Progressive JPEG encoding

Token Budget

~500 per invocation (simple bash execution).

Platform

macOS only. Requires ImageOptim.app installed.