Serving large binary files via an application framework of any kind (whether MVC, WebAPI, Rails, WebForms, or HttpHandlers) is generally a bad idea.
The ImageResizer Best Practices guide explains in more detail.
To get good performance, you should implement this as a URL rewrite (or IVirtualImageProvider) instead.
Handle ImageResizer's Config.Current.Pipeline.Rewrite
event, and parse the path yourself. Modify the Path based on the ID you parsed, and increment your view counter. This should require 5-8 lines of code.