This document provides an overview of the image system in Drupal 8 compared to Drupal 7. It discusses the key changes to image loading and saving, image styles, image effects, image toolkits, and image toolkit operations between the two versions. The main points are that images are now objects loaded via a factory, image styles are configuration entities, effects and operations are plugins, and functionality is now defined through plugins rather than hooks.
20. How to add your
image style effect?
Create your own
@ImageEffect
plugin
In your module directory, drop it under
lib/Drupal/mymodule/Plugin/ImageEffect/
31. How to add your
image toolkit operation?
Create your own
@ImageToolkitOperation
plugin
In your module directory, drop it under
lib/Drupal/mymodule/Plugin/ImageToolkit/Operation/{toolkit}/