Home
Cameras
Cameras News
Disney's Local Tone Mapping Technique Gives HDR Video Finer Detail

Disney's Local Tone Mapping Technique Gives HDR Video Finer Detail

By Press Trust of India | Updated: 6 December 2014 17:03 IST

A new image processing technique developed by Disney Research could make high dynamic range (HDR) video look better when show on consumer-quality displays.

The technique works by preserving much of the rich visual detail while eliminating 'ghosting' and other unwanted visual artefacts.

The combination of HDR acquisition and the new technique enables video effects such as showing the detail of an actor's face even as lighting shifts from shadow to direct sunlight and back to shadow.

HDR is a means of capturing images with a greater range of lighting and contrast - from dark shadows to bright sunlight - than is possible with standard photography and that is closer to how people perceive natural scenes.

But HDR currently outstrips the dynamic range that most televisions and video monitors can display, so HDR video must go through a process called tone mapping to adapt those images to the limitations of displays.

A number of such techniques, or tone mapping operators (TMO), exist, noted Tunc Aydin, an Associate Research Scientist at Disney Research Zurich. But though they reduce the dynamic range of the video, they either lose some of the visual details or they introduce unwanted effects, such as brightness flickering, or amplify camera noise to create ghosting.

The local tone mapping method developed by Aydin and his colleagues at Disney Research uses an approach taken with many TMOs - decomposing the signal into a base and a detail layer. In that way, the dynamic range of the base layer can be reduced while preserving a great amount of detail and fine scale contrast.

The main difference that the Disney team introduced is using a temporal filter on the detail layer and a spatiotemporal filter on the base layer. They also developed a simple interface that enables a user to perform tone mapping interactively once the base and detail layers have been pre-computed.

Researchers found that the technique was capable of tone mapping video sequences with complex motion and lighting changes and was worked particularly well in low-light situations where camera noise was high.

Comments

For the latest tech news and reviews, follow Gadgets 360 on X, Facebook, WhatsApp, Threads and Google News. For the latest videos on gadgets and tech, subscribe to our YouTube channel. If you want to know everything about top influencers, follow our in-house Who'sThat360 on Instagram and YouTube.