How to do setup for microbencharks?

I'm trying to benchmark how long rotating different image resolutions takes. Each benchmark will be rotating the given Bitmap, and is therefore editing it. I want to reset this bitmap before each benchmark, so I looked into the [IterationSetup] attribute. The docs say, however, that this should not be used for microbencmarks. Since rotating a Bitmap takes less than 100ms and therefore is a microbenchmark, I was wondering how would I go about doing Setup for such a problem if I can't use [IterationSetup]?