How to remove alpha channeled margins from an image using ImageMagick

Question

I have an image that all four margins are transparent alpha channels and I want to crop all margins and only keep the non-alpha channel parts. Is there any way to do it with ImageMagick? Take this image as an example but consider its transparent margins!

Answer 1

You can do that in Imagemagick using -trim to automatically remove the constant transparent regions.

convert img.png -trim +repage result.png