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Disney Research Tone Mapping Technique Creates “HyperReal” Look, Avoids Visible Artifacts In High Dynamic Range Video
Method Works Particularly Well In Low Light Sequences With Significant Camera Noise
A new image processing technique developed by Disney Research Zurich could make
high dynamic range (HDR) video look better when shown on consumerquality displays
by preserving much of the rich visual detail while eliminating “ghosting” and other
unwanted visual artifacts.
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.
The workings of the local tone mapping technique and how it compares with previous
techniques was presented at SIGGRAPH Asia 2014, the ACM SIGGRAPH Conference
on Computer Graphics and Interactive Techniques, Dec. 36 in Shenzhen, China.
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 precomputed.
The researchers found that the Disney tone mapping technique was capable of tone
mapping video sequences with complex motion and lighting changes and was worked
particularly well in lowlight situations where camera noise was high.
More information and an explanatory video are available on the project website
http://www.disneyresearch.com/publication/hdrvideo/ and
https://www.youtube.com/watch?v=6yItM8UB7k4 .
###
About Disney Research
Disney Research (www.disneyresearch.com) is a network of research laboratories
supporting The Walt Disney Company. Its purpose is to pursue scientific and technological
innovation to advance the company's broad media and entertainment efforts. Vice
Presidents Jessica Hodgins and Markus Gross manage Disney Research facilities in
Los Angeles, Pittsburgh, Zürich, and Boston and work closely with the Pixar and ILM
research groups in the San Francisco Bay Area. Research topics include computer graphics, animation, video processing,
computer vision, robotics, wireless & mobile computing, humancomputer interaction,
displays, behavioral economics, and machine learning.
Method Works Particularly Well In Low Light Sequences With Significant Camera Noise
A new image processing technique developed by Disney Research Zurich could make
high dynamic range (HDR) video look better when shown on consumerquality displays
by preserving much of the rich visual detail while eliminating “ghosting” and other
unwanted visual artifacts.
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.
The workings of the local tone mapping technique and how it compares with previous
techniques was presented at SIGGRAPH Asia 2014, the ACM SIGGRAPH Conference
on Computer Graphics and Interactive Techniques, Dec. 36 in Shenzhen, China.
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 precomputed.
The researchers found that the Disney tone mapping technique was capable of tone
mapping video sequences with complex motion and lighting changes and was worked
particularly well in lowlight situations where camera noise was high.
More information and an explanatory video are available on the project website
http://www.disneyresearch.com/publication/hdrvideo/ and
https://www.youtube.com/watch?v=6yItM8UB7k4 .
###
About Disney Research
Disney Research (www.disneyresearch.com) is a network of research laboratories
supporting The Walt Disney Company. Its purpose is to pursue scientific and technological
innovation to advance the company's broad media and entertainment efforts. Vice
Presidents Jessica Hodgins and Markus Gross manage Disney Research facilities in
Los Angeles, Pittsburgh, Zürich, and Boston and work closely with the Pixar and ILM
research groups in the San Francisco Bay Area. Research topics include computer graphics, animation, video processing,
computer vision, robotics, wireless & mobile computing, humancomputer interaction,
displays, behavioral economics, and machine learning.