“The attempt at blackmail was well-advanced until it failed,” said Judge Joachim Spieth, of the court in the town of Kirchheim unter Teck in Baden-Württemberg.
The sentenced man, Edis Kayalar, had threatened to sell the photo to the media. The photo was apparently taken by Crawford's daughter's former nanny and showed the girl, then aged seven, tied to a chair wearing shorts and a T-shirt.
The girl told her parents, who were unaware of the image, that the nanny had taken the photograph as part of a "cops and robbers" game.
Kayalar, a friend of the nanny, took possession of the photo and threatened Crawford, 44, and her husband Rande Gerber with its release unless they met his demands, officials said.
The couple reported the extortion attempt as soon as Kayalar approached them, authorities said, triggering an FBI investigation. Kayalar then fled to Germany.
A professional model who was already known to police for drug offences, Kayalar received the maximum sentence of two years for the extortion attempt.