Xbox Kinect helps further development of holographic TV
Researchers in the US have brought holographic TV a step closer by turning a motion-capture gaming device into a specialised camera.
A team at the Massachusetts Institute of Technology (MIT) used a Microsoft Kinect device to create the first single-camera holographic video system.
Previous attempts to create a hologram transmission unit have used multiple cameras and the image only changed every few seconds.
With the Kinect, the MIT team has been able to capture an average of 15 frames per second and is confident that with faster software it could boost this to the 30 frames per second used by TV cameras.
Holographic video is a way of making images appear 3D without the viewer wearing special glasses by capturing data about how light bounces off objects in view from multiple angles.
If commercialised, it could have a particular use in realistic video conferencing, as well as for entertainment.
Unlike with traditional 3D video footage, which is the same viewed from any angle, the holographic image changes with the viewer’s perspective, giving the impression of a fully 3D object.
‘Using a single camera is more convenient than a whole array of cameras,’ principal research scientist Michael Bove, director of MIT’s Consumer Electronics Laboratory, told The Engineer.
‘The Kinect is useful because it provides depth information, and we can use that to make a 3D model of the scene from which we can compute the hologram.’
Where standard 3D cameras record two images from slightly different perspectives, the MIT system records the light intensity and the distance from the camera of each pixel of the image.
This data is then converted into fine ‘fringe’ patterns of light and dark that can bend the light passing through them in order to simulate the effect of light bouncing off a three-dimensional object.
Bove’s team has been able to convert the data and make it appear on the holographic display using a standard graphics chip at a rate of 15 frames per second.
He said the main focus of the work was making the technology as cheap as possible by taking advantage of hardware and software that already exists in order to speed up its commercialisation.
The team is also working on a cheaper and more compact holographic display screen that produces larger images.
‘A holographic video display is fundamentally a hologram [a diffraction pattern that reconstructs light waves as if they were coming from a 3D physical object] that changes electronically,’ he said.
‘It needs to have much higher resolution and smaller pixels than a TV. There are a number of ways of achieving such a display; ours uses an acousto-optic modulator, which is a device that converts electrical signals into diffraction patterns inside a piece of transparent material.’