This Robin Williams foto contains
snap randhut, schnappen sie randhut, snap krempe hut, filzhut, homburg, stetson, trilby, fedora, stetson trilby, kampagne hut, and kampagnenhut.
There might also be
porkpie, porkpie hut, boater, leghorn, panama, panamahut, seemann, skimmer, hut stroh, bootsfahrer, bein, strohhut, livorno, panama-hut, biber, rizinus, rolle, and castor.