setaspect is a simple CLI to adjust the aspect ratio of PNG images by adding transparent padding.
Really, I just want to post screenshots on twitter and have them formattted appropriately.
For that reason, the default aspect ratio is 16:9.
go install github.com/chrisseto/setaspect@latest
Write to an output file:
setaspect -o ./what-i-will-post-on-twitter.png /.my-screenshot.png
Or redirect to an output file
setaspect ./my-screenshot.png > ./what-i-will-post-on-twitter.png
Or just use the online version.