RMagick can also be used to get an image size (and to change images in
many
ways.
Use,e.g.,
cheetah = Magick::Image.ping(“Cheetah.jpg”) »
[Cheetah.jpg JPEG 1024x768 DirectClass 8-bit 101684b]
p cheetah[0].rows » 768
p cheetah[0].columns » 1024
see :
http://www.simplesystems.org/RMagick/doc/image1.html#ping
(http://www.simplesystems.org/RMagick/doc/image1.html#ping)
Best regards,
Axel