The module looks simple, thanks for the opportunity to try it.This module gives you the most easy and convenient way to regenerate your thumbnail images especially if you have a large catalog. It’s using a batch ajax technic, so no more timeout during the regeneration process. The old thumbnails deleted right before generate the new one, so no more missing thumbnail. You just select the desired image type and format or select all, it generates a process queue so you can track the regeneration status.
https://addons.prestashop.com/en/visual-products/20351-regenerate-image-thumbnails.html#overview