huiz

The plugin affects the uploaded image while it is uploaded. Straight 
after it is uploaded, it it resized physically to the given width. 
There is no original image left, nor made a backup. Also EXIF infor- 
mation is lost.
A lot of WordPress users or developers who use WordPress as a CMS 
and want to configurate it for easy use, would like to have an option 
to resize uploaded images. Some images come straight from digital cameras 
and exceed 4000 pixels in width. So it would be nice to reduce that to 
the max width you use inside your WordPress theme.
If you want to keep control about perfect sharp and resized images, you 
better use photo editing tools on your computer, not a script like this.
The plugin uses a class originally from Jacob Wyke (www.redvodkajelly.com).

Resize at Upload

This plugin resizes uploaded images to a given width.

ERA404

Extends the WordPress Media Library to allow individual control over each media item size’s crop.
For those particular about their imagery…
WordPress’s Media Library already gives authors strong, intuitive organization over their web site’s images. But some users are a little more particular than others over the individual crop sizes of each media item. CropRefine is for the keen-eyed, visual types who want something fast and fastidious.
<ul>
<li>CropRefine provides quick-links from the Media Library to refine each item.</li>
<li>A full catalog of existing crops and sizes are made available for refinement.</li>
<li>If you prefer a different/better thumbnail but want to leave the other sizes untouched, CropRefine gives you that level of granularity over your imagery.</li>
<li>Packaged with cropper.js, adjusting a crop is a smooth, draggable, precise refinement experience.</li>
<li>Iterative backups are stored alongside each adjustment, so nothing is ever lost—only gained!</li>
<li>If a re-crop just won’t achieve the results you’re after, a quick-upload tool is also offered for each media item size, so that you can replace that (and only that) size.</li>
<li>No additional database is needed, no exhaustive setup process, no hidden license costs.</li>
</ul>

CropRefine

Giving you greater control over how each of your media item sizes are cropped.

Resize at Upload vs CropRefine