How to find the dimensions of an uploaded image

Rails
1

Hi! I’m trying to make a site that can upload image files, but
instead of posting each picture as their size, I’d rather post them in
thumbnails (thank goodness html can warp images for you). I need to
know how I can find a dimension of an image WITHOUT using a plugin
(the server I am soon uploading this to most likely won’t have that
plugin…and I don’t feel like forcing the administrators to download
it). Are there any methods to take care of this?

Thanks!

2

Hi! I’m trying to make a site that can upload image files, but
instead of posting each picture as their size, I’d rather post them in
thumbnails (thank goodness html can warp images for you). I need to
know how I can find a dimension of an image WITHOUT using a plugin
(the server I am soon uploading this to most likely won’t have that
plugin…and I don’t feel like forcing the administrators to download
it). Are there any methods to take care of this?

This will work for most jpegs…

http://pastie.caboo.se/98119

Don’t remember where I got it… probably off of pastie in the first
place
:slight_smile:

If you have other image types you could find code to handle those and
work
that in. PHP’s getimagesize() method does most of them… and they all
do
it about the same way (read some bytes, do some math).

-philip

3

I found some TCL code to do that here:

It shouldn’t be too hard to port that to ruby. :slight_smile:

  • Tyler
4

Hi, in addituion to what the others have posted, I would first check
what
plugins are available on the host.

Good luck,

-Conrad