NYCPHP Meetup

[Chris Snyder]

The topic of ImageMagick came up at last night's meeting, as a way for 
PHP to work with images.
http://www.imagemagick.org/

I recommend it highly, as it is meant to be scriptable via the command 
line (and therefore via PHP shell_exec()). It's really a suite of 
commands-- the ones you're probably most interested in are convert and 
identify.

For instance, when someone uploads an image to fotola.com, here's the 
call that resizes and/or rotates it, strips any IPTC or APP16 headers, 
and compresses it at medium compression:

$command= "/usr/local/bin/convert jpeg:$tempfile -rotate $rotate 
-geometry \\"500x500>\\" -quality 95 +profile \\"*\\" jpeg:$filename"
exec($command);

 - $rotate is some number of degrees
 - the > after 500x500 means resize only if the image doesn't fit in the 
500x500 box
 - resizing is automatically proportional
 - the +profile "*" option strips all extra info from the image (making 
it 2-3KB smaller)
 - Be sure to properly escape all user input to exec() calls!!!

There is a PHP extension (coauthored by Michael Montero of Community 
Connect, no less)  that makes ImageMagick accessible to PHP without the 
exec calls, but I haven't used it yet-- might be much easier.
http://pear.php.net/package-info.php?pacid=76


    chris.