London, Oct 10 (IANS) Drastically gaining or losing body weight for a coveted film role has long proved the ultimate test for method actors.

Robert De Niro piled on the pounds for his Oscar-winning turn in ‘Raging Bull’, and Christian Bale starved himself to the point of emaciation for ‘The Machinist’.

Scientists have developed a new kind of image manipulation software that promises to allow filmmakers to alter the appearance of their actors without resorting to time-consuming frame-by-frame digital touch-ups.

What has until now taken either the most dedicated of actors, or a painstakingly slow process of computer editing, can be done in a relatively short period of time, reports the Daily Mail.

The new software, called MovieReShape, has been developed by Christian Theobalt and his team at the Max Planck Institute for Informatics in Saarbrucken, Germany.

The researchers generated 3D scans of 120 men and women of varying shapes and sizes pulling various poses, according to New Scientist magazine.

They then fed these scans into a computer, merging them together to create a single model that can be morphed into any desired pose.

Programmers can then use existing software to track an actor’s silhouette throughout a sequence of frames, and then map the silhouette onto the malleable 3-D model.

The software can be manipulated to simultaneously adjust an actor’s height, weight and muscle tone, without having to resort to the painfully slow process of digital touch-ups, one frame at a time.

So, are the days of actors embarking on potentially dangerous diets to alter their physical appearance gone forever?

Theobalt said: ‘The actor wouldn’t need to go to all that trouble.’