How about this: An IIR on a fixed-size data set such as an image can be implemented as an FIR with a filter width the size of the image, if I recollect correctly. The classic use of IIRs to provide feedback into a signal aren't nearly as useful for the most part in image processing, where there is a distinctly limited data size. There are some examples of low-pass filtering out there (often under the term recursive filters rather than IIR), but it's not a particularly common usage, in my experience.