Generating icons for PWAs with imagemagick convert and the command line

instruct.md

Generate a set of icons for the manifest, index metadata, so forth.

convert raw-icon.png \
  \( -clone 0 -resize 512x512 -write icon-512.png \) \
  \( -clone 0 -resize 384x384 -write icon-384.png \) \
  \( -clone 0 -resize 192x192 -write icon-192.png \) \
  \( -clone 0 -resize 144x144 -write icon-144.png \) \
  \( -clone 0 -resize 96x96 -write icon-96.png \) \
  \( -clone 0 -resize 72x72 -write icon-72.png \) \
  \( -clone 0 -resize 48x48 -write icon-48.png \) \
  -alpha on null:

Generate a multi-layer PNG ICO

convert raw-icon.png -define icon:auto-resize=48,32,16 favicon.ico