I've checked Clarifai, Google, and Microsoft cognitive services with this photo https://farm4.staticflickr.com/3232/2492569957_1e5ebdec11_b_d.jpg https://farm4.

I've checked Clarifai, Google, and Microsoft cognitive services with this photo https://farm4.staticflickr.com/3232/2492569957_1e5ebdec11_b_d.jpg https://farm4.staticflickr.com/3232/2492569957_1e5ebdec11_b_... (mariachis in a boat in Xoximilco lake) - this should be hard to classify, of course. This are the results: NONE of them identified people as mariachis ;-) Microsoft: Captions: "a group of people on a boat" Tags: outdoor, sky, tree, boat Clarifai (TAGS): people, vehicle, water, festival watercraft, transportation system, tourist, travel tourism, city, adult, group boat, recreation, man, outdoors competition, canal, sfw transportation, travel Google (tags): Boat 79% Vehicle 77% Boating 67% Waterway 58% Raft 53% My only conclusion is that both Google, Clarifai, and Microsoft are doing a great job. You should take a look at what you need and choose the best provider.