Overview of our research in holovideo
Holovideo papers
Links to holovideo-related work
TV of Tomorrow Research - where Cheops began.
Our TVoT page from 1995
Spatial Imaging Group
Holovideo on the cover of Frames, 1993 Sept
Our sponsors
The next photo shows the real-time holovideo display system as it
appeared in 1991.
Photo of Interactive Holovideo Display System
The holographic fringe pattern use to create the interactive image in
the above photo contained 2 MB of information, and was computed on a
massively parallel supercomputer (a Connection Machine Model 2 with 16
Kprocessors). A time-multiplexed scanned acousto-optic modulator
transfers the fringe pattern onto a beam of light at a rate of over
100 MB/s.
In our most recent work on real-time holographic display systems, a 36-MB system produces an image that is approximately 140 mm wide, 80 mm tall, and 150 mm deep. The following picture shows schematically the layout of the current 36-MB holovideo display system.
This is what the display setup looks like:
A new approach to fringe computation - called Diffraction-Specific fringe computation - has yielded two types of holographic bandwidth compression. Diffraction-Specific fringe computation is based on the spatial and spectral discretization of the hologram. The hologram is treated as a regular array of holographic elements called "hogels." Each hogel is a small piece of the hologram and possesses a homogeneous spectrum (distribution of spatial frequencies). [This research was performed by Mark Lucente, former member of the Spatial Imaging Group.] The first method of holographic bandwidth compression, called Hogel-Vector Encoding, is a two-step process. First, an array of hogel vectors (one representing the discretized spectrum of one hogel) is computed from the 3-D object scene description. In the second step, each hogel vector is decoded into a hogel (the usable fringe) through the linear superposition of a set of precomputed basis fringes. Hogel-Vector decoding has been implemented using the Cheops Image Processing system and the Splotch Engine - a superposition stream-processing daughter card. The second method of holographic bandwidth compression is called Fringelet Encoding. A fringelet is computed for each hogel, and each fringelet is rapidly decoded to produce fringes. This method is designed to reduce the total number of calculations required per fringe sample, increasing computation speeds by over 100 times. Fringelet Encoding promises to greatly simplify the design and contruction of holovideo displays.
Current Holovideo Researchers:
We are grateful to our numerous sponsors, past and present: