Please read this before answering: I know we can flush the BLOB cache and it will fix the problem.
But we're giving the power of updating the dimensions to end users and they might do it frequently. Flushing BLOB cache isn't the solution here.
We are using
https://sharepoint.com/PublishingImages/someImage.jpg?RenditionID=xx to refer to the rendition image.
The browser cache is the problem here. How can we tell the browser to make sure it asks the server when the image dimensions are updated?
PS: I had a look at ImageRendition object and it does contain a Version property, but even if I change the dimensions it still remains 1.