Smoothing a wrinkled black fabric backdrop

A pregnant woman in a mustard gown and a man kissing her belly in front of a creased black fabric backdrop, with a metal shelf, a window and a light stand visible beyond its edges.

Fictional demonstration. A couple's maternity session in a small studio, where the black backdrop came out of storage creased and was too narrow for the wide frame.

Keep in mind: Beyond the edges of the original cloth, the backdrop is filled in by estimate. The fabric texture is evened out, so the backdrop and the people are not pixel-identical.