Zebra Imaging produces both static and dynamic holographic lightfield displays and display technologies. ZScape Prints are film-based images, produced in a plotter-like “printer” of our own invention and design, with thousands of sub-millimeter size hogels permanently encoded in a plastic sheet. The lightfield is activated by illuminating the sheet with a point-source of light in a simple display. The dynamic display is a different beast, however, offering the ability to produce a lightfield display in an interactive, animated form - analogous to a LCD monitor's abilities in 2D. There is another page on Zebra's site that describes this in more detail.

Zebra Imaging dynamic and interactive holographic lightfield display technology, called ZScape Motion Display (“ZMD”), is a display platform developed with support from DARPA. ZMDs are produced in tile-able units, which can be assembled to create arbitrary sized displays in a variety of orientations. The display is integrated through a simple Ethernet connection and a background software agent that runs on a host computer in parallel with the users’ choice 3D software application. ZMD interprets standard computer graphics API scene descriptions and generates and produces holographic lightfields internally, independently, but in synchrony with the host machine. Update rates can range from minutes to milliseconds, depending on the particular ZMD configuration and the complexity of the 3D data. Zebra has demonstrated true, real-time interaction with 3D scenes and objects, as well as streaming holographic telepresence coupling the display with dynamic LIDAR and 3D sensor systems such as the Microsoft Kinect. Details, photos and movies of ZMD prototypes can be seen on Zebra Imaging’s website and I've posted some descriptions of the function of hogels and such in responses to some of the questions and comments above.

There are many definitions of “holographic” these days, and in this case, Zebra Imaging has developed a lightfield-generating display that is “holographic” in the sense that it produces super-imposed arrays of wavefronts, representing a scene or object as mother nature does, but at various levels of approximation. The scene can be perceived in 3D without the need for glasses or head- or eye-tracking. Holographic lightfield displays are the most natural form of 3D display in the sense that they can provide all of the depth-cues for volumetric perception and thus produce no distortion or viewer discomfort or fatigue. See my comments above on the hogel vs. voxel definition.

The basic element in Zebra Imaging’s displays, though not yet a food item, is the hogel. While a pixel is a gridded sample of a 2D image or bitmap, a hogel is a (usually gridded) sample of a lightfield at a specific surface. A pixel provides luminance information that is more or less consistent with viewing position. A hogel, by contrast, provides varied luminance depending on viewing position (as you move around the object represented by the hogels changes). This effect may be achieved through interference and diffraction, or through other combinations of intensity modulation and refraction, reflection, and/or diffraction. A voxel, also by contrast, is a (usually cubic) sample of a 3D space or object with a single associated luminance value for that sample. Unlike pixels and hogels, voxels are not linked to or part of a specific surface. The term “hogel” was coined at MIT in the early 1990’s, a few doors down from where the plenoptic function concept of lightfields was developed.