ImageMagick Quick Reference: Essential Image Operations 🖼️

Your go-to cheat sheet for common ImageMagick operations with both legacy and modern syntax

⚠️ Legacy vs Modern Commands

Legacy (ImageMagick v6): convert Modern (ImageMagick v7): magick or magick convert

Warning: The convert command is deprecated in IMv7. Use magick instead of convert or magick convert

🔄 Basic Resize & Crop Operations

Resize with Canvas Extension

# Legacy
convert out.png -resize 2516x1718 -gravity center -extent 3555x2000 out2.png

# Modern
magick out.png -resize 2516x1718 -gravity center -extent 3555x2000 out2.png

Resizes image to fit within 2516x1718, then extends canvas to 3555x2000 centered

Smart Resize Options

# Resize maintaining aspect ratio
magick input.png -resize 800x600 output.png

# Force exact dimensions (may distort)
magick input.png -resize 800x600! output.png

# Resize only if larger
magick input.png -resize 800x600> output.png

# Resize only if smaller
magick input.png -resize 800x600< output.png

📐 Image Merging & Concatenation

Horizontal Merge (Left-Right)

# Legacy
convert +append 1.png 2.png out.png

# Modern
magick 1.png 2.png +append out.png

Vertical Merge (Top-Bottom)

# Legacy
convert -append 1.png 2.png out.png

# Modern
magick 1.png 2.png -append out.png

🎨 Adding Borders & Padding

Basic Border

# Legacy
convert 1.png -bordercolor "#FFFFFF" -border 0x100 out2.png

# Modern
magick 1.png -bordercolor "#FFFFFF" -border 0x100 out2.png

⚠️ Important: Settings like -bordercolor must come BEFORE the option that uses them (-border)

Advanced Border Options

# Different border sizes
magick input.png -bordercolor "#FF0000" -border 10x20 output.png

# Rounded corners with border
magick input.png -bordercolor black -border 5 -fill white -opaque black output.png

🔗 Advanced Merging Techniques

Merge with Different Dimensions

1. Resize to Match Height (Horizontal Merge)

# Get height of first image, resize second to match
magick identify -format "%h" 1.png > height.txt
magick 2.png -resize x$(cat height.txt) 2_resized.png
magick 1.png 2_resized.png +append merged.png

2. Resize to Match Width (Vertical Merge)

# Get width of first image, resize second to match
magick identify -format "%w" 1.png > width.txt
magick 2.png -resize $(cat width.txt)x 2_resized.png
magick 1.png 2_resized.png -append merged.png

3. One-liner Solutions

# Horizontal merge - resize all to same height (smallest)
magick 1.png 2.png -resize x600 +append output.png

# Vertical merge - resize all to same width (smallest)
magick 1.png 2.png -resize 800x -append output.png

Merge with Padding/Spacing

# Add 20px white space between images horizontally
magick 1.png \( -size 20x1 xc:white \) 2.png +append output.png

# Add 20px transparent space between images vertically
magick 1.png \( -size 1x20 xc:transparent \) 2.png -append output.png

# Add colored separator
magick 1.png \( -size 5x1 xc:"#CCCCCC" \) 2.png +append output.png

Smart Auto-Resize Merging

# Horizontal merge with auto-height matching
magick 1.png 2.png -background white -gravity center -extent 0x+0+0 +append output.png

# Vertical merge with auto-width matching
magick 1.png 2.png -background white -gravity center -extent +0+0x0 -append output.png

🎯 Precise Positioning & Alignment

Custom Positioning

# Place second image at specific coordinates on first
magick 1.png 2.png -geometry +100+50 -composite output.png

# Center second image on first
magick 1.png 2.png -gravity center -composite output.png

Grid Layouts

# 2x2 grid
magick 1.png 2.png +append row1.png
magick 3.png 4.png +append row2.png
magick row1.png row2.png -append grid.png

# Clean up
rm row1.png row2.png

🛠️ Utility Commands

Get Image Information

# Basic info
magick identify input.png

# Specific dimensions
magick identify -format "%wx%h" input.png

# Detailed info
magick identify -verbose input.png

Batch Operations

# Resize all PNGs in directory
magick mogrify -resize 800x600 *.png

# Convert format for all images
magick mogrify -format jpg *.png

📝 Pro Tips & Best Practices

1. Order Matters

# ❌ Wrong - settings after the operation
magick input.png -border 10 -bordercolor red output.png

# ✅ Correct - settings before the operation
magick input.png -bordercolor red -border 10 output.png

2. Background Colors for Transparency

# Set background color for operations that might create transparency
magick input.png -background white -flatten output.png

3. Memory Management for Large Images

# Limit memory usage
magick -limit memory 1GB input.png -resize 50% output.png

4. Quality Control

# Set JPEG quality
magick input.png -quality 90 output.jpg

# PNG compression level
magick input.png -define png:compression-level=9 output.png

🔄 Migration Helper

Quick Command Conversion

Replace your old commands:

# Old way (v6)
convert image.png -resize 800x600 output.png

# New way (v7)
magick image.png -resize 800x600 output.png

Batch Script Migration

#!/bin/bash
# Replace 'convert' with 'magick' in all your scripts
sed -i 's/^convert /magick /' your_script.sh

📚 Common Use Cases Summary

Task Legacy Command Modern Command
Resize convert in.png -resize 800x600 out.png magick in.png -resize 800x600 out.png
Horizontal merge convert +append 1.png 2.png out.png magick 1.png 2.png +append out.png
Vertical merge convert -append 1.png 2.png out.png magick 1.png 2.png -append out.png
Add border convert in.png -bordercolor white -border 10 out.png magick in.png -bordercolor white -border 10 out.png
Canvas extend convert in.png -gravity center -extent 1920x1080 out.png magick in.png -gravity center -extent 1920x1080 out.png

Keep this reference handy for quick ImageMagick operations! Remember: settings before operations, and embrace the new magick command for future-proof scripts. ✨