Camera captures range of real-world light
U. WARWICK (UK) — The world’s first complete high dynamic range (HDR) camera can capture high-quality video in a wide range of lighting conditions, including inside the human body.
The camera is capable of 20 f-stops, full HD (1920 × 1080) resolution at 30 frames per second. Researchers at the University of Warwick developed the technology and will demo it January 19 in the first ever showing of a short film shot using this new HDR technology.
“We have put together unique compression software with a high performance HDR camera and HDR displays that will revolutionize the use of HDR in a range of applications,” says Alan Chalmers, an engineering professor. “The impact will be enormous, for example, the ability to clearly see the football when it is kicked from the shadow of the stadium into sunshine or surveillance cameras which can detect detail even in extreme lighting conditions.”
Chalmers says the team recently put the technology through a test run assisting a thoracic surgery team and documenting a procedure. “HDR is able to accurately capture for the first time the wide range of lighting present in an operation from the dark body cavities through to the bright highlights on the shiny medical instruments.
“The natural world presents us with a wide range of colors and intensities. In addition, a scene may be constantly changing with, for example, significant differences in lighting levels going from outside to inside or simply as the sun goes behind some clouds etc,” adds Chalmers.
“A human eye can cope with those rapid changes and variety but a traditional camera is only capable of capturing a limited range of lighting in any scene. The actual range it can cope with depends on the exposure and f-stop setting of the camera. Anything outside that limited range is either under- or over-exposed.”
Chalmers says HDR imagery offers a more representative description of real-world lighting by storing data with a higher bit-depth per pixel than more conventional images.
“Although HDR imagery for static images has been around for 15 years, it has not been possible to capture HDR video until now. However such HDR images are typically painstakingly created in computer graphics or generated from a number of static images, often merging only 4 exposures at different stops to build an HDR image.
Chalmers says HDR also can complement 3D technology by providing depth perception without the need to wear 3D glasses.
The work was supported by the Engineering and Physical Sciences Research Council.
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