A display technology that can sense ambient light levels, and adjust its appearance to suit in real time, has been developed by a team of researchers at Columbia University in New York.
Dubbed “Lighting Sensitive Displays” or “LSD” for short, the technology is claimed to overcome a major drawback among the current generation of computer displays; their inability to respond to external lighting conditions. “Whether electronic billboards or laptop monitors, today’s displays produce ‘flat’ images that have no relation to their surroundings,” says Shree Nayar, a professor of computer science at Columbia.
Nayar developed LSDs technology with two other computer scientists, Peter Belhumeur of Yale University and Terry Boult of Lehigh University. The technology enables, for example, a digital image of a museum sculpture on a computer display to have all the colours, shadings, highlights and shadows needed to make the sculpture look like it was illuminated from the actual lighting in the museum.
“To achieve a high degree of realism, you need to ensure that the displayed objects appear to be actually ‘lit’ by their external illumination,” continues Nayar.
LSD technology operates in several ways. For still-life pictures, several thousand images can be collected from different angles with various levels of light and then compressed into a single data file. A photosensitive detector on the display senses the ambient illumination—the intensities and directions of light hitting the display—and then matches it to the stored image that resembles the real situation.
The sensing electronics comprise an arrangement of photosensitive detectors or optical fibres distributed around the object, or a wide-angle camera placed close to the device.
“The idea is to explicitly use the measured light rays hitting your [object] to render the content you want to display,” explains Nayar. “Because you can embed the illumination sensors and chips [into the object] you don’t need an external computer to make a display ‘light sensitive’.”