Image Forge
Pixel-precise image editing with three-tier routing: deterministic CLI tools for exact operations, AI models for semantic edits, vision models for analysis.
Routing Decision
Use AI when the edit requires understanding what is in the image. Use ImageMagick when the edit requires knowing exactly what to do to the pixels.
Tier 1: Deterministic (magick, sips, rembg)
Use for operations with exact, numeric parameters:
| Task | Tool | Command |
|---|---|---|
| Resize to exact dimensions | magick | magick in.jpg -resize 800x600! out.jpg |
| Resize fit (preserve aspect) | magick | magick in.jpg -resize 800x600 out.jpg |
| Resize fill + crop | magick | magick in.jpg -resize 800x600^ -gravity center -extent 800x600 out.jpg |
| Resize shrink only | magick | magick in.jpg -resize '800x600>' out.jpg |
| Crop at offset | magick | magick in.jpg -crop 600x400+100+50 +repage out.jpg |
| Center crop | magick | magick in.jpg -gravity center -crop 600x400+0+0 +repage out.jpg |
| Auto-trim whitespace | magick | magick in.jpg -fuzz 10% -trim +repage out.jpg |
| Format convert | magick | magick in.png -quality 85 out.jpg |
| Add text | magick | magick in.jpg -fill white -pointsize 36 -annotate +10+50 'Text' out.jpg |
| Composite overlay | magick | magick bg.png fg.png -geometry +50+100 -composite out.png |
| Watermark | magick | magick photo.jpg wm.png -gravity SouthEast -geometry +10+10 -compose Dissolve -define compose:args=25 -composite out.jpg |
| Adjust brightness/contrast | magick | magick in.jpg -brightness-contrast 10x20 out.jpg |
| Adjust saturation | magick | magick in.jpg -modulate 100,130,100 out.jpg |
| Grayscale | magick | magick in.jpg -colorspace Gray out.jpg |
| Sepia | magick | magick in.jpg -sepia-tone 80% out.jpg |
| Blur | magick | magick in.jpg -blur 0x3 out.jpg |
| Sharpen | magick | magick in.jpg -sharpen 0x1 out.jpg |
| Remove background | rembg | rembg i in.jpg out.png |
| Strip metadata | magick | magick in.jpg -strip out.jpg |
| Set DPI | magick | magick in.jpg -density 300 out.jpg |
| Batch resize | batch_ops.py | python3 scripts/batch_ops.py *.jpg --op resize --width 800 --output resized/ |
| Montage/contact sheet | magick | magick montage *.jpg -geometry 200x200+5+5 -tile 4x out.jpg |
| Quick format convert (macOS) | sips | sips -s format jpeg in.png --out out.jpg |
| Quick resize (macOS) | sips | sips -Z 800 in.jpg --out out.jpg |
Tier 2: AI Semantic (nano-banana-pro / Gemini)
Delegate to the nano-banana-pro skill when the edit requires understanding image content:
- Remove a person/object from a photo
- Change sky, weather, time of day
- Apply artistic style transfer
- Inpaint/outpaint regions
- Generate new image from scratch
- Content-aware fill after object removal
Tier 3: Vision Analysis (Claude Read tool)
Use the Read tool to inspect images before/after edits:
- Verify an edit succeeded
- Describe image contents
- Check composition and framing
- Identify colors, objects, text in image
Scripts
All scripts are in ~/.claude/skills/image-forge/scripts/. Run with python3.
image_info.py — Inspect Image Metadata
python3 ~/.claude/skills/image-forge/scripts/image_info.py photo.jpg
python3 ~/.claude/skills/image-forge/scripts/image_info.py photo.jpg --field dimensions
python3 ~/.claude/skills/image-forge/scripts/image_info.py photo.jpg --field widthReturns clean JSON: dimensions, format, color space, depth, alpha, DPI, ICC profile, EXIF.
image_pipeline.py — Declarative Edit Pipeline
Write a JSON spec, get a single chained magick command. No intermediate files.
# Create spec
cat > /tmp/pipeline.json << 'EOF'
{
"input": "photo.jpg",
"output": "result.png",
"steps": [
{"op": "resize", "width": 800, "height": 600, "mode": "fill"},
{"op": "brightness_contrast", "brightness": 5, "contrast": 10},
{"op": "annotate", "text": "Title", "gravity": "South", "pointsize": 36, "fill": "white", "stroke": "black", "strokewidth": 2},
{"op": "composite", "overlay": "watermark.png", "gravity": "SouthEast", "opacity": 25},
{"op": "quality", "value": 90},
{"op": "strip"}
]
}
EOF
# Dry run (print command)
python3 ~/.claude/skills/image-forge/scripts/image_pipeline.py /tmp/pipeline.json --dry-run
# Execute
python3 ~/.claude/skills/image-forge/scripts/image_pipeline.py /tmp/pipeline.jsonAvailable operations:
| Op | Parameters |
|---|---|
resize | width, height, mode (fit/fill/exact/shrink/enlarge/percent), filter |
crop | w/width, h/height, x, y, gravity |
trim | fuzz (%) |
annotate | text, font, pointsize, fill, stroke, strokewidth, gravity, x, y |
composite | overlay, gravity, x, y, opacity, compose, resize |
rotate | angle, background |
blur | sigma, radius |
sharpen | sigma, radius |
unsharp | sigma, radius, amount, threshold |
modulate | brightness, saturation, hue (100 = no change) |
brightness_contrast | brightness, contrast |
levels | black, white, gamma |
gamma | value |
sigmoidal_contrast | strength, midpoint |
colorize | color, amount (%) |
sepia | threshold (%) |
grayscale | (none) |
negate | (none) |
auto_level | (none) |
normalize | (none) |
auto_orient | (none) |
flip / flop | (none) |
border | color, size |
extent | width, height, background, gravity |
shadow | opacity, sigma, x, y |
transparent | color, fuzz (%) |
alpha_remove | background |
alpha_set | (none) |
quality | value (1-100) |
strip | (none) |
density | value (DPI) |
draw | primitive, fill, stroke, strokewidth |
raw | args (string or array of raw magick args) |
smart_crop.py — Gravity-Based Smart Crop
python3 ~/.claude/skills/image-forge/scripts/smart_crop.py photo.jpg --target 800x600
python3 ~/.claude/skills/image-forge/scripts/smart_crop.py photo.jpg --target 800x600 --gravity north
python3 ~/.claude/skills/image-forge/scripts/smart_crop.py photo.jpg --target 1080x1080 --output cropped/
python3 ~/.claude/skills/image-forge/scripts/smart_crop.py photo.jpg --target 800x600 --dry-runGravities: center, north, south, east, west, northwest, northeast, southwest, southeast.
batch_ops.py — Parallel Batch Processing
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.jpg --op resize --width 800 --output resized/
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.png --op format --to jpg --quality 85 --output converted/
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.jpg --op thumbnail --width 200 --height 200 --output thumbs/
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.jpg --op strip --output clean/
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.jpg --op watermark --overlay wm.png --opacity 25 --output marked/
python3 ~/.claude/skills/image-forge/scripts/batch_ops.py *.jpg --op resize --width 800 --parallel 8 --output resized/Operations: resize, thumbnail, format, strip, auto_orient, watermark, crop.
montage_builder.py — Contact Sheets
python3 ~/.claude/skills/image-forge/scripts/montage_builder.py *.jpg --output contact.jpg
python3 ~/.claude/skills/image-forge/scripts/montage_builder.py *.jpg --cols 3 --thumb 300x300 --label --output grid.jpg
python3 ~/.claude/skills/image-forge/scripts/montage_builder.py *.jpg --background '#1a1a2e' --border 2 --output dark_grid.jpgQuick Recipes
Social Media Crops
# Instagram square
magick in.jpg -resize 1080x1080^ -gravity center -extent 1080x1080 instagram.jpg
# Instagram story
magick in.jpg -resize 1080x1920^ -gravity center -extent 1080x1920 story.jpg
# Twitter/X header
magick in.jpg -resize 1500x500^ -gravity center -extent 1500x500 header.jpg
# OG image
magick in.jpg -resize 1200x630^ -gravity center -extent 1200x630 og.jpgWatermark
# Text watermark
magick photo.jpg -fill 'rgba(255,255,255,0.3)' -gravity SouthEast \
-font Helvetica -pointsize 24 -annotate +10+10 '© 2026' out.jpg
# Image watermark at 25%
magick photo.jpg wm.png -gravity SouthEast -geometry +10+10 \
-compose Dissolve -define compose:args=25 -composite out.jpgBorders and Shadows
# Solid border
magick in.jpg -bordercolor '#333' -border 10 out.jpg
# Drop shadow
magick in.png \( +clone -background black -shadow 60x5+5+5 \) \
+swap -background none -layers merge +repage shadow.pngColor Effects
# Vintage
magick in.jpg -modulate 105,80,100 -fill '#704214' -colorize 15% \
-sigmoidal-contrast 3x60% vintage.jpg
# High contrast B&W
magick in.jpg -colorspace Gray -sigmoidal-contrast 10x50% bw.jpgGeometry Syntax Quick Reference
| Syntax | Meaning |
|---|---|
800x600 | Fit within box, preserve aspect |
800x600! | Force exact (distort) |
800x600> | Shrink only if larger |
800x600< | Enlarge only if smaller |
800x600^ | Fill box (minimum dimension matches) |
50% | Scale by percentage |
+X+Y | Offset from gravity anchor |
Shell escaping: Quote geometry with >, <, ^:
magick in.jpg -resize '800x600>' out.jpgCritical Reminders
- Always
+repageafter-crop— Virtual canvas offset persists without it -modulateorder is B,S,H — Brightness, Saturation, Hue (not H,S,L)- Settings persist, operators execute immediately — Order matters in magick commands
- Use
rembgfor background removal —rembg i input.jpg output.png(add-afor alpha matting) - Quote geometry —
>,<,^are shell metacharacters -alpha offis permanent in IM7 — Use-alpha deactivate/-alpha activatefor temporary toggle- Inspect before editing — Run
image_info.pyfirst to know dimensions, format, alpha state - Pipeline for multi-step — Use
image_pipeline.pyinstead of chaining shell commands
References
Detailed references in ~/.claude/skills/image-forge/references/:
magick-reference.md— Complete ImageMagick 7 command reference (resize, crop, color, text, drawing, batch, identify)compositing.md— All compositing operators (Duff-Porter, mathematical, lighting, HSL, special)recipes.md— 30+ recipes (borders, shadows, watermarks, social sizing, color effects, sprites, batch patterns)
Dependencies
| Tool | Version | Install |
|---|---|---|
| ImageMagick | 7.1.2-7 (Q16-HDRI) | brew install imagemagick |
| rembg | 2.0.72 | uv pip install rembg |
| sips | macOS built-in | — |
| Pillow | 10.4.0 | uv pip install Pillow |