CImage (works with PHP GD)
Resizing and cropping images on the server side by caching generated image files using PHP. Requires PHP 5.3+ and soon PHP 5.4+
GitHub https://github.com/mosbth/cimage
Another alternative would be SLIR (works with PHP GD)
(Smart Lencioni Image Resizer) resizes images, intelligently sharpenes, yields based on width: height, color, fill transparent GIF and PNG files, as well as cache options for optimal performance. Requires PHP 5.1.2 +
It does not seem to support external images. But for the local, this is fine.
GitHub https://github.com/lencioni/SLIR
Posted by TimThumb is no longer supported or supported. You can read the reasons why on my blog: [TimThumb End of Life] [1]
You also have TimThumb (works with PHP GD)
It is widely used in the world of Wordpress. It can be implemented almost identically phpThumb, but requires PHP 5.2 +
GOOGLE CODE https://code.google.com/p/timthumb/
TIMTHUMB PAGE http://www.binarymoon.co.uk/projects/timthumb/
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