I was working with Image Renditions in Office 365 recently and switched to test something out on a SharePoint 2013 farm in our Dev Lab. When I checked the images in an Image library the Edit renditions option was missing. I checked all the immediately obvious things but I couldn’t figure out and didn’t have the time to dig further.

Then today, whilst reviewing the Blob Cache configuration guidance I came across this statement in a TechNet article.

For a publishing site that plans to use the image renditions feature, you must enable the BLOB cache.

Aha! That’s why it was missing! I checked the web.config for the Web Application in the Dev Lab, and yes, it was disabled. Hopeful, I switched it to enabled and checked the Image Library to find the missing option had appeared. Problem solved. 🙂

References:

Plan for caching and performance in SharePoint Server 2013
https://technet.microsoft.com/en-us/library/ee424404.aspx#Section1a