# CLI Imagemagick > Covers effective use of ImageMagick for image conversion, resizing, cropping, compositing, batch processing, and creating favicons, thumbnails, watermarks, and animated GIFs. Activates when the user wants to manipulate images, convert formats, batch-resize photos, or create image assets programmatically. - Skill: `ryankolean/cli-imagemagick` (Agent Skill) - Install (CLI): `npx skillmds@latest add ryankolean/cli-imagemagick` - Raw SKILL.md: https://api.skillmd.com/api/skills/ryankolean/cli-imagemagick/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: ryankolean (https://skillmd.com/u/ryankolean) - Updated: 2026-09-21 - Page: https://skillmd.com/skills/ryankolean/cli-imagemagick --- # ImageMagick — Image Manipulation Suite **Repo:** https://github.com/ImageMagick/ImageMagick Create, edit, compose, and convert images from the command line. Supports 200+ formats. The standard tool for programmatic image manipulation. > **Note:** ImageMagick 7+ uses the `magick` command. Version 6 uses `convert`, > `identify`, `mogrify`, etc. as separate commands. Examples use `magick` > (v7) — replace with `convert`/`identify`/`mogrify` if on v6. ## When to Activate **Manual triggers:** - "Resize these images" - "Convert images to PNG/JPEG/WebP" - "Create a thumbnail" - "Watermark images" - "Create a favicon" - "Make an animated GIF from frames" **Auto-detect triggers:** - User needs to batch-process a folder of images - User needs image assets at specific dimensions for web/app - User wants to add text or a logo overlay to images - User extracted frames from FFmpeg and wants to process them ## Key Commands ### Inspect Images (magick identify) ```bash magick identify image.png # Basic info (format, size, depth) magick identify -verbose image.png # Full metadata magick identify -format "%wx%h\n" *.jpg # Print dimensions for all JPEGs magick identify -format "%f: %wx%h %[colorspace]\n" *.png # Custom format ``` ### Basic Conversion ```bash magick input.png output.jpg # Convert format magick input.jpg -quality 85 output.jpg # Set JPEG quality (1-100) magick input.png -quality 90 output.webp # Convert to WebP magick *.png output.pdf # Combine images into PDF magick input.pdf output-%04d.png # PDF pages to PNG sequence ``` ### Resize (-resize) ```bash magick input.jpg -resize 800x600 output.jpg # Resize to fit within 800x600 magick input.jpg -resize 800x output.jpg # Width 800, height proportional magick input.jpg -resize x600 output.jpg # Height 600, width proportional magick input.jpg -resize 800x600! output.jpg # Force exact size (distorts) magick input.jpg -resize 800x600^ output.jpg # Fill (crop to fit) 800x600 magick input.jpg -resize 50% output.jpg # 50% of original size magick input.jpg -resize 800x600> output.jpg # Only shrink (don't enlarge) magick input.jpg -resize 800x600< output.jpg # Only enlarge (don't shrink) ``` ### Crop (-crop) ```bash magick input.jpg -crop 400x300+100+50 output.jpg # width x height + x_offset + y_offset magick input.jpg -gravity Center -crop 400x300+0+0 output.jpg # Crop from center magick input.jpg -trim output.jpg # Auto-trim whitespace/border ``` ### Rotate, Flip, Flop ```bash magick input.jpg -rotate 90 output.jpg # Rotate 90° clockwise magick input.jpg -rotate -45 output.jpg # Rotate 45° counter-clockwise magick input.jpg -flip output.jpg # Vertical flip magick input.jpg -flop output.jpg # Horizontal flip magick input.jpg -auto-orient output.jpg # Fix EXIF orientation ``` ### Color Adjustments ```bash magick input.jpg -brightness-contrast 10x20 output.jpg # Brightness +10, contrast +20 magick input.jpg -modulate 100,150,100 output.jpg # Brightness,Saturation,Hue magick input.jpg -colorspace Gray output.jpg # Grayscale magick input.jpg -negate output.jpg # Invert colors magick input.jpg -level 20%,80% output.jpg # Levels (black/white point) magick input.jpg -sigmoidal-contrast 3,50% output.jpg # S-curve contrast magick input.jpg -colorize 10,0,0 output.jpg # Add red tint ``` ### Blur and Sharpen ```bash magick input.jpg -blur 0x2 output.jpg # Gaussian blur, radius 0, sigma 2 magick input.jpg -sharpen 0x1 output.jpg # Unsharp mask sharpen magick input.jpg -unsharp 0x1+0.5+0.1 output.jpg # Fine-tuned unsharp mask magick input.jpg -median 3 output.jpg # Median filter (noise reduction) ``` ### Text Overlay (-annotate) ```bash magick input.jpg \ -font Arial -pointsize 48 -fill white -gravity South \ -annotate +0+20 "Photo Caption" \ output.jpg # With stroke/outline magick input.jpg \ -font Arial -pointsize 48 \ -fill white -stroke black -strokewidth 2 \ -gravity Center -annotate +0+0 "Watermark" \ output.jpg ``` ### Border and Padding ```bash magick input.jpg -border 10x10 -bordercolor white output.jpg # White border magick input.jpg -border 5% -bordercolor black output.jpg # 5% border magick input.jpg -gravity Center -extent 900x600 output.jpg # Pad to exact canvas size ``` ### Shadow and Effects ```bash magick input.png -background none -shadow 50x5+4+4 \ \( +clone -background none -shadow 50x5+4+4 \) \ +swap -background white -layers merge output.png magick input.jpg -vignette 0x20 output.jpg # Vignette effect magick input.jpg -charcoal 1 output.jpg # Charcoal sketch effect magick input.jpg -oil-paint 3 output.jpg # Oil paint effect ``` ### Transparency (-alpha) ```bash magick input.png -alpha set -background none output.png # Preserve transparency magick input.jpg -transparent white output.png # Make white pixels transparent magick input.png -fuzz 10% -transparent "#ffffff" output.png # Fuzzy transparency ``` ## Advanced Patterns ### Batch Processing with mogrify (in-place) ```bash # Resize all JPEGs in a folder (modifies originals!) magick mogrify -resize 1200x1200> *.jpg # Convert all PNGs to JPEG (different extension = new files) magick mogrify -format jpg *.png # Resize and add watermark to all images, output to ./thumbs/ mkdir -p thumbs magick mogrify -path thumbs -resize 300x300^ -gravity Center \ -extent 300x300 -font Arial -pointsize 18 -fill "rgba(255,255,255,0.5)" \ -gravity SouthEast -annotate +5+5 "© 2024" *.jpg ``` ### Create Favicon (Multi-Size ICO) ```bash # Generate all sizes from a source SVG or large PNG magick source.png -resize 16x16 favicon-16.png magick source.png -resize 32x32 favicon-32.png magick source.png -resize 48x48 favicon-48.png magick source.png -resize 64x64 favicon-64.png # Combine into .ico magick favicon-16.png favicon-32.png favicon-48.png favicon-64.png favicon.ico # One-liner magick source.png -define icon:auto-resize=64,48,32,16 favicon.ico ``` ### Thumbnail Generation with Cropping ```bash # Smart crop (crop-to-fill at exact size) magick input.jpg -resize 300x300^ -gravity Center \ -crop 300x300+0+0 +repage thumb.jpg # Batch thumbnails preserving aspect ratio (letterbox) magick input.jpg -thumbnail 300x300 -background white \ -gravity Center -extent 300x300 thumb.jpg ``` ### Watermarking ```bash # Image watermark (logo overlay) magick composite -gravity SouthEast -geometry +10+10 \ logo.png input.jpg output.jpg # Semi-transparent text watermark across entire image magick input.jpg \ \( -size 200x50 xc:none -font Arial -pointsize 24 \ -fill "rgba(255,255,255,0.3)" -gravity Center \ -annotate 0 "CONFIDENTIAL" \) \ -gravity Center -composite output.jpg ``` ### Image Comparison ```bash magick compare input1.jpg input2.jpg diff.jpg # Visual diff magick compare -metric PSNR input1.jpg input2.jpg diff.jpg # PSNR metric magick compare -metric AE input1.jpg input2.jpg diff.jpg # Absolute error pixels ``` ### Create Animated GIF from Frames ```bash # From image sequence (50ms delay = 20fps) magick -delay 5 -loop 0 frame*.png animation.gif # Control per-frame delay magick \( frame1.png -delay 100 \) \( frame2.png -delay 50 \) \ -loop 0 animation.gif # Optimize GIF file size magick -delay 5 -loop 0 frame*.png -layers optimize animation.gif ``` ### Create Contact Sheet / Montage ```bash # 4-column contact sheet with labels magick montage *.jpg -geometry 200x200+5+5 -tile 4x montage.jpg # Uniform grid, white background magick montage *.png -background white -geometry 150x150+2+2 \ -tile 5x -border 1 -bordercolor gray sheet.jpg ``` ### Color Profile Conversion ```bash magick input.jpg -profile /path/to/sRGB.icc -profile /path/to/CMYK.icc output.tif magick input.jpg -colorspace sRGB output.jpg # Convert to sRGB magick input.jpg -strip output.jpg # Strip all metadata/profiles ``` ### SVG to PNG Rendering ```bash magick -background none input.svg output.png # Transparent background magick -background white -density 150 input.svg output.png # 150 DPI rasterization magick -density 300 input.svg -resize 1000x output.png # High-res render ``` ### PDF to Images ```bash # Requires Ghostscript magick -density 150 input.pdf output-%04d.png # All pages to PNG at 150 DPI magick -density 150 "input.pdf[0]" cover.jpg # First page only ``` ### Sprites for Web ```bash # Horizontal sprite strip magick icon1.png icon2.png icon3.png +append sprite.png # Vertical sprite strip magick icon1.png icon2.png icon3.png -append sprite.png # Grid sprite magick montage icon*.png -geometry +0+0 -tile 4x sprite.png ``` ## Chaining with Other Skills - **cli-ffmpeg:** Extract video frames with FFmpeg (`-vf fps=1 frame_%04d.png`), then use ImageMagick's `mogrify` to batch-resize, watermark, or convert the frames - **fd:** Use `fd -e jpg` to find all images recursively, pipe into a shell loop with `magick` for batch processing - **cli-fzf (fzf):** Use `fd -e png | fzf` to interactively select an image before running a `magick` command - **cli-pandoc:** Use ImageMagick to generate or preprocess images that are embedded in documents converted by Pandoc