HDR stands for High Dynamic Range, a technique that gives an image greater dynamic range to better highlight the differences between shadow and highlight detail. Traditional video cameras have difficulty in capturing a range of light as they are only using a single exposure to form the image, resulting in footage that might not look quite the same as the human eye sees.
The standard method for constructing an HDR image involves taking multiple exposures of an image or video and merging the results together in post-production.
Professor Alan Chalmers of the WMG Visualisation Research Group at the university outlined the new HDR system, which involves a complete method to capture and view HDR video. Using special compression software in conjunction with an HDR camera, the technology allows the camera to cover 20 f-stops — or aperture diameters — at full HD at 30fps. The footage also has potential applications in glasses-less 3D by providing better depth perception.
The system would theoretically allow a videographer to capture footage in tricky lighting situations without the need for lighting crews to illuminate a subject. While similar cameras have been developed before, both for still and video capture, this is the first video system that integrates capture and display. The HDR monitor used to display the footage consists of an LCD screen with an LED panel behind it, which gives the extra visual information.
According to the research team, the system will have many potential applications, including filming medical procedures, sports and surveillance. “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,” Professor Chalmers said in a statement.
“We have also recently successfully trialled its use to assist and document surgery together with the thoracic surgery team and the multimedia group at Heartlands Hospital. 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,” he said.