[xplorer]

Resizing with GD has one pitfall - thumbnails look too soft. This is why the upcoming version 4.2 not just resizes images with GD, but also applies "unsharp mask" filter on thumbnails that makes the thumbs clean and sharp.

Note: I've just looked through the Smart Image Resizer (the link posted above) code and noticed that it applies a "sharpness" filter on images too (it uses imageconvolution() function that is available starting from php 5.1.0).