IT notes

extent

To resize an image and adjust it to fit a fixed canvas with transparent background: $ convert in.png \ -resize 128x128 \ -background none \ -gravity center \ -extent 128x128 \ out.png

combine two images

Combine in a single file 2 images: convert +append a.png b.png out.png -append will append vertically instead of horizontally (+)

transparent

Create an image with transparent background Using convert from imagemagick: convert input.jpg -fuzz 10% -transparent white transparent.png