The latest cult horror movie to be restored and re-released by Fun City Editions, 1982’s transgressively weird “Der Fan” centers on a teen girl’s obsessive fixation on a pop star — a fixation that takes a turn for the cannibalistic. Writer/director Eckhart Schmidt’s classic video nasty was last restored in 2015 by Mondo Macabro, but the disturbing, German New Wave-era film has never before played U.S. theaters. “Der Fan” was restored in 4K from its original 35mm camera negative by Fun City Editions. The film is presented with its original stereo soundtrack for the first time since its initial German theatrical release in 1982. “Der Fan” will open at the Metrograph in Lower Manhattan starting August 28.