Konrád Koller

This plugin helps you to fix any missing thumbnail issue in a fairly short time. The only thing you need to do is just few simple click and the plugin does the rest. It can be really helpful if you have thousands of images in your database.
You can regenerate thumbnails for each single image in your database or you can simply select those you really want to update. If you choose a post or page the plugin will regenerate thumbnails for each related images. You can choose from the following methods:
<ul>
<li>Regenerate thumbnails for all images in the database.</li>
<li>Bulk action in post liste: You can choose which one to update by checking the checkboxes.</li>
<li>Media library items: Move your mouse over the chosen image(s) and click on “Regenerate thumbnails” link.</li>
<li>Post editor: click on “Regenerate thumbnails” button which is next to “Add media” button. (Off by default)</li>
</ul>
Furthermore you can add your own thumbnails sizes, change default JPG compression rate and mass regenerate thumbnails. The best thing about this plugin is that you can use it with custom post types as well.

ONet Regenerate Thumbnails

Doesnt have 4.4.1 bulk generation support. But you can generate thumbnails one by one.



Doesnt have 4.4.1 support completely

Fix missing thumbnails in no time with few easy clicks. The plugin does the hard work.

stasionok

Take some thumbnail type (called here as preset) and cast available image effects on it to get expected size or view.
With this plugin you can:
<ul>
<li>change exists preset or create new one.</li>
<li>on upload image create only enabled preset thumbnails</li>
<li>disable unused presets</li>
<li>remove disabled or extra/trash thumbnails images</li>
<li>regenerate any preset thumbnail images (after change preset as ex.)</li>
</ul>
For each preset you can cast any of available effects to change thumbnail sizes or just desaturate it or something else..

Thumbnails like in Drupal

I’m a drupal developer and i like this module. Its really looks like a drupal image style with image effects. Big thumbs up for the developer of this module. Hope to enhance and improve this in the future.

This really looks like image style of drupal

Wordpress implementation/fork of Drupal imagecache module.

ONet Regenerate Thumbnails vs Thumbnails like in Drupal