rick@pangea.Stanford.EDU (Rick Ottolini) (01/17/91)
In article <1991Jan15.233942.21236@wam.umd.edu> jonnyg@wam.umd.edu (Jon Greenblatt) writes: > > Has anyone heard of some type of technology to produce holographic >images from a computer generated holographic pattern. I can think of See 1/91 Popular Science for a description of how MIT Media Lab does this.
jsivier@ux1.cso.uiuc.edu (Jonathon Sivier ) (01/17/91)
jonnyg@wam.umd.edu (Jon Greenblatt) writes: > Has anyone heard of some type of technology to produce holographic >images from a computer generated holographic pattern. I can think of >two ways of doing this right now, the second being the most likely. . . . > JonnyG. There have been several running discussions on this in comp.graphics and a few other newsgroups. As I recall this is being done as you read this. I don't remember any of the names but there are several people doing research in this area and at least one commercial outfit manufacturing holograms from computer data. I have a friend here at the U of I who has developed a method of producing holograms from 2 or more photographs (stereo pairs), obviously it would be simple to make those photographs with a computer and a film recorder. Jonathan Sivier ------------------------------------------------------------------- | Jonathan Sivier | Ballo ergo sum. | | jsivier@ux1.cso.uiuc.edu | (I dance therefore I am.) | | Flight Simulation Lab | - des Cartwright | | Beckman Institute, Urbana IL | | -------------------------------------------------------------------
bhoughto@pima.intel.com (Blair P. Houghton) (01/17/91)
In article <1991Jan15.233942.21236@wam.umd.edu> jonnyg@wam.umd.edu (Jon Greenblatt) writes: > > Has anyone heard of some type of technology to produce holographic >images from a computer generated holographic pattern. I can think of >two ways of doing this right now, the second being the most likely. It's called pscholography. CNN had a bit on this the day after I bought a small pscholograph for a friend for christmas. A pscholograph is a high-tech version of those "magic pictures" you used to get as Cracker-Jack prizes. A computer generates a 3-D situation, which is then represented by projecting it onto visual planes at every few degrees of rotation. The images are then shone onto the film at the corresponding angle. Covering the film is a diffraction grating with linewidth/linespacing large enough to prevent diffraction of external visual light (which would overwhelm any image transmitted from teh film); the basic reason for using a diffraction grating is just to get many, many, many images onto the film. I.e., the plastic-toy ones would only change the image every 30 degrees or so, allowing only a few images to be stored. With the smaller linespacing, however, the images can change every few tenths of a degree. The larger linewidth blocks out all the other images. Diffraction may serve to blur the lines together. 3-D effects are generated by parallax; your left eye simply sees a different picture from the one your right eye sees. Motion can be stored. The one I bought had both the 3-D and motion. The quality of the cheap ones isn't terriffic. Vertical registration was poor, so adjacent images didn't quite line up, and the picture bounced. The CNN story showed some really nice ones, printed on media several feet across. --Blair "How far across is the electronic medium?"
sandin@uicbert.eecs.uic.edu (Dan Sandin) (01/22/91)
bhoughto@pima.intel.com (Blair P. Houghton) writes: >It's called pscholography. CNN had a bit on this the day after >I bought a small pscholograph for a friend for christmas. > --Blair > "How far across is the electronic medium?" I am one of the 3 or 4 people responsible for PHSColography, and I can tell you, you most assuredly did not buy a PHSCologram for Xmas. PHSCologram (tm) is the product of (Art)^n laboratory. Since 1987, they have been entirely computer-generated (not produced by the photographic means you mentioned) and are usually 20"x24". You bought a lenticular (basically the same deal, but not computer-generated, and with a lenticular screen instead of a barrier screen). The name PHSCologram comes from Photography, Holography, Sculpture, and Computer graphics. stephan meyers, assoc dir. (Art)^n laboratory c/o sandin@uicbert.eecs.uic.edu 319 wishnick hall 3255 s. dearborn chicago, IL 60616 (312) 567-6908 FAX fax for more info...