Imagine a Noel Coward exhibition, and you’d expect a dressing gown or two. But you might not anticipate paintings by the writer-composer-director-actor himself.Such art is among the memorabilia on display as part of Star Quality: The World of Noel Coward, an exhibition from the New York Public Library for the Performing Arts and the Noel Coward Foundation. There are also opening-night gifts, an Oscar and a Tony as well as letters, manuscripts and set and costume sketches by designers Coward worked with on Broadway and beyond. Opening March 12, the exhibition — part of a citywide Coward festival that also includes screenings at the Film Society of Lincoln Center and AMPAS — covers all periods of the creative’s life. That includes his later years in Jamaica, which inspired his colorful, primitivistic painting. “He called the style ‘Touch and Gauguin,’ ” said curator Brad Rosenstein. The Coward exhibition has been seen in four prior incarnations, but according to Rosenstein, this Gotham version incorporates a trove of never-before-seen stuff. And that includes dressing gowns — including one signature robe he wore in “Present Laughter.” “It’s a knockout,” Rosenstein said. Exhibition runs March 12-Aug. 18 at the Lincoln Center homebase of the NYPL for the Performing Arts.