Note: most of these are in place conversions.
Only shrink larger images
magick $i -resize 800x600\> $i
Shrink and convert to webp
magick test.png -resize 800x600\> test.webp
Trim borders and shrink if larger
I use the following for cover art on this website:
magick $i -trim -resize 140x183\> $i
I use the following for card art on this website:
magick $i -trim -resize 75x105\> $i