i think,its quite okay i put some text above my adsense ads but sometimes,its very dangerous still confuse about it but my account is active until now
best practice is always get in contact with google and if they do ban you at least you got something to show to them but they can always have tons of other reason.
Google does frown on image placements that are too close and that could be confused as part of their ad displays. I would err on the side of caution and make sure your images could not be confused as part of their ads. Yours, Barry.