Updated for Phoenix
Automatic create on the fly Thumbnails for all your images:
This add-on improves the page load time serving all images in just the required image size on all places.
Features:
Configurable min. image size to use thumbs
Equal image size adding background if necesary to smaller images
Equal image proportion adding background if necesary
Add watermark for images bigger than configured (including big images in pop-up of product_info)
Show customizable no image available thumb if image is missing
WEBP, JPEG, GIF and PNG images supported
Configurable JPEG and WEBP quality
In RGB configurable Background color
3 level sharpness filter
Transparent GIF and PNG suport
Reset thumbnails from Admin
Optional support for Admin
New Version Pro for Phoenix available:
KissIT Image Thumbnailer Pro
It allows to auto convert all image formats (jpeg. png, gif) to webp images.
Webp format offers smaller images and therefore faster page load than all other image formats with the same image quality.
Pro introduces support for the html tag “srcset:” It allows to indicate the browser that different versions of an image are available to fit the different needs of high resolution/retina devices and smaller devices.
Version: 4.7.1
Installation:
Very easy
Copy files and 2 new images
No file changes
Configuration entries will be automatic installed on first admin page load
Copy new files and 2 new images
Compatibility:
Phoenix Cart 1.0.9.9+
Tested with Phoenix Cart 1.0.9.9
PHP 7.0 - 8.3
Phoenix Cart Support Forum:
KissIT Image Thumbnailer 
