ImageMagick Help
 

-resize 300x300 will resize it so the LARGEST side is 300, no matter the inital geometry.

Is there a way to have the SMALLEST side to be 300, not knowing the image size?

Not that I am aware of. You'll have to get the image size first and then resize from that.

Try this page.
http://www.imagemagick.net/MagickStudio/Resize.html

:)

Thanks! You too have helped me :)

try to resize to 300x1000 or some unrealistically large number on the longest side. it worked when i tried it.