Image::Size returns a raw (X, Y) pair of the height and width of
an image, and includes wrappers to pre-format that output into
either HTML or a set of attribute pairs suitable for the CGI.pm
library by Lincoln Stein.

Currently Image::Size can size images in XPM, XBM, GIF, JPEG, PNG,
TIFF, PCD and the PPM family of formats (PPM/PGM/PBM).