In a heavy traffic site with large number of images flushing an image style, or change image style shown in page could cause performance issues, when large number of images want to be generated in the same time. With this module you can generate all the images for a particular image style and when that's ready you can change e.g. an imagefield format style to use this new style safely.
The module provides an action for the following entity types:
Also provides VBO based views for all entity types, you can start the process at admin/config/media/image-styles/ispre
The settings page of an operation is simple, just choose which preset(s) you want to use, and which field contains the images to generate.
Please note that whenever you adjust a setting on an existing image style, the respective folder holding the image files will be immediately flushed, so you better create a new image style instead, generate all images in advance and then switch to the new image style in your field formatter for instance.
The functionallity is quite similar as that given by Rules Image Style, the main difference is that Image Style Pregenerate is designed for bulk image generation, instead of action based (eg. create images when new node is generated) process.