If you only really care how the image is displayed on a web page, another, lighter, solution would be to use Image::Info to get the dimensions and some simple arithmetic to determine the desired height and width attributes for your img tag.

If you actually want to change the size of the image use one of the other solutions mentioned. Just so you know, Image::Magick is a sledgehammer and GD is somewhat limited in the formats it will deal with.

-sauoq
"My two cents aren't worth a dime.";