attachment_fu max height/width

I think the best way is to resize image without error confirmation.
Simple add: :resize_to => [50,50]
to the has_attachment.
Or if you really want to check size, then you may use validate method,
and check for the
if width > your_width_max and height > your_height_max

Look into this article:

Thanks for what, what was the solution... I still don't see any way to
find out the dimensions of the original image, nor can I find
information anywhere about how to get the original dimensions, just
using "width" doesn't work.