image-tools

Image Tools

CLI-first image manipulation using ImageMagick (raster) and vtracer (raster-to-vector).

Prerequisites

# Check if installed
which magick && echo "imagemagick OK" || echo "need: brew install imagemagick"
which vtracer && echo "vtracer OK" || echo "need: cargo install vtracer"

Install if missing:

brew install imagemagick    # raster image editing
cargo install vtracer       # raster-to-vector conversion (Rust)

Raster-to-SVG Conversion

Simple flat icon (single/few colors)

Best for logos, icons, flat illustrations:

vtracer --input input.png --output output.svg \
  --colormode color \
  --filter_speckle 10 \
  --color_precision 4 \
  --corner_threshold 60 \
  --segment_length 6 \
  --gradient_step 32

High-detail image

For complex images, increase precision:

vtracer --input input.png --output output.svg \
  --colormode color \
  --filter_speckle 4 \
  --color_precision 6 \
  --corner_threshold 60 \
  --segment_length 4

Black-and-white / monochrome

For line art, text, or single-color designs:

vtracer --input input.png --output output.svg --colormode bw

Tuning guide

• file too large → increase filter_speckle, gradient_step, decrease color_precision
• too rough/blocky → decrease segment_length, filter_speckle
• too many colors → decrease color_precision (1-8, lower = fewer colors)

Raster Editing with ImageMagick

Remove watermark / overlay

Paint over a region with a solid color (e.g. matching background):

# Get image dimensions first
magick identify input.png

# Paint rectangle over bottom-right corner (100x100 area)
magick input.png -fill "#0F0F0F" -draw "rectangle 1180,1180 1280,1280" output.png

Resize

# Resize to specific width, maintain aspect ratio
magick input.png -resize 512x output.png

# Resize to exact dimensions
magick input.png -resize 512x512! output.png

# Resize to fit within bounds (no upscale)
magick input.png -resize 512x512\> output.png

Crop

# Crop to 500x500 from top-left
magick input.png -crop 500x500+0+0 output.png

# Crop from center
magick input.png -gravity center -crop 500x500+0+0 output.png

Format conversion

magick input.png output.jpg
magick input.jpg output.webp
magick input.png -quality 85 output.jpg

Trim whitespace / transparent borders

magick input.png -trim +repage output.png

Threshold (prepare for BW tracing)

magick input.png -threshold 50% output.pbm

Common Workflows

Clean image then convert to SVG

When source image has watermarks, logos, or artifacts:

# 1. Check dimensions
magick identify input.jpg

# 2. Remove unwanted elements (paint over with background color)
magick input.jpg -fill "#BACKGROUND" -draw "rectangle x1,y1 x2,y2" clean.jpg

# 3. Convert to SVG
vtracer --input clean.jpg --output output.svg --colormode color \
  --filter_speckle 10 --color_precision 4 --corner_threshold 60 \
  --segment_length 6 --gradient_step 32

# 4. Check output size (aim for <50KB for icons)
ls -la output.svg

Create favicon from logo

# Resize to favicon sizes
magick logo.png -resize 32x32 favicon-32.png
magick logo.png -resize 16x16 favicon-16.png

# Or create .ico with multiple sizes
magick logo.png -resize 256x256 -define icon:auto-resize=256,128,64,48,32,16 favicon.ico

Decision Guide

Task	Tool
PNG/JPG → SVG	vtracer
Resize, crop, format convert	magick
Remove watermark	magick (paint over) → then vtracer if SVG needed
Trim borders	magick
Create favicon	magick