Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/image/image.api.php

@@ -0,0 +1,43 @@
+<?php
+
+/**
+ * @file
+ * Hooks related to image styles and effects.
+ */
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * Alter the information provided in \Drupal\image\Annotation\ImageEffect.
+ *
+ * @param $effects
+ *   The array of image effects, keyed on the machine-readable effect name.
+ */
+function hook_image_effect_info_alter(&$effects) {
+  // Override the Image module's 'Scale and Crop' effect label.
+  $effects['image_scale_and_crop']['label'] = t('Bangers and Mash');
+}
+
+/**
+ * Respond to image style flushing.
+ *
+ * This hook enables modules to take effect when a style is being flushed (all
+ * images are being deleted from the server and regenerated). Any
+ * module-specific caches that contain information related to the style should
+ * be cleared using this hook. This hook is called whenever a style is updated,
+ * deleted, or any effect associated with the style is update or deleted.
+ *
+ * @param \Drupal\image\ImageStyleInterface $style
+ *   The image style object that is being flushed.
+ */
+function hook_image_style_flush($style) {
+  // Empty cached data that contains information about the style.
+  \Drupal::cache('mymodule')->deleteAll();
+}
+
+/**
+ * @} End of "addtogroup hooks".
+ */