ing their bets. ÒWeÕve been approachedby a lot of people. WeÕre not doing any-thing that is either permanent or diÛ-cult to back away from,Ó says CharlesS. MoÝett, director of the Phillips Collec-tion in Washington, D.C. A few muse-umsÑespecially small, technologicallyaware ones, such as the Michael C. Car-los Museum in AtlantaÑare taking mat-ters into their own hands by makingtheir collections available on the Inter-net via the World Wide Web. Even theSmithsonian Institution is getting inthe act, oÝering digital images throughAmerica Online.

Some critics worry that the limitedresolution and poor color accuracy ofcomputer monitors degrade the qualityof the art. Most museums, however,seem Þrmly convinced that familiarityincreases interest in the original work.A more serious concern involves main-taining control of images. One startlingfeature of Art GalleryÑand of any un-protected CD-ROMÑis that it allows

users to copy the images oÝ the diskand manipulate them on the computer.Drawing a mustache on the Mona Lisahas never been so easy. Defacing repro-ductions of great art is hardly a newgame, but what is novel is the ability tocreate, save and erase the changes.

The legal departments of museumsare still coming to grips with the impli-cations of digitized artworks. They willhave to determine which breaches ofelectronic rights they wish to pursue. ÒIdonÕt know that there is a solution. Le-gally, you just go after the biggest of-fenders,Ó says Alan B. Newman, execu-tive director of imaging at the Art Insti-tute of Chicago. Museums may try toattach copyright tags to images thatthey post through the Internet, as theSmithsonian does.

As Ben Davis points out, digitized artÒis a medium you can literally do any-thing with: itÕs transmissible, itÕs alter-able, you can make new art out of it.ÓAlready lawsuits are blooming over the

appearance of pirated cartoon charac-ters and scanned-in Playboy nudes onthe Internet; manipulated Þne-art imag-es are also beginning to show up. Thelimited resolution of current CD-ROMor on-line images restricts their useful-ness. But soon it will be easy to storeand transmit publication-quality digi-tized artworks. Some computer-literatemuseum employees are starting tothink about ways to encrypt such im-ages so that only authorized users canlook at them.

Last summer the Association of ArtMuseum Directors held a special meet-ing, ÒArt Museums on the InformationSuperhighway,Ó to consider the philo-sophical implications of digital art andto sort out questions about image own-ership in the electronic age. ÒThe com-puter makes capitalism very transpar-entÑitÕs all about property rights,Ó BenDavis reßects. ÒThe problem is, muse-ums donÕt see themselves in the art-in-formation business.Ó ÑCorey S. Powell

SCIENTIFIC AMERICAN January 1995 31

They fit the profile of certain illicit drugs: ubiquitous,addictive, the cause of euphoria as well as irritability

and lassitude. Like LSD, they are available as dots on pa-per. But while stereograms seem psychedelic in origin,they are actually the product of psychology, military re-search and art.

The popularity of three-dimensional viewing of two-di-mensional images dates to the early 1800s, when the ste-reoscope was invented. It was not until the 1950s, howev-er, that so-called random-dot stereograms, which resem-

ble Jackson Pollack paintings,were created. At that time, ac-cording to the October 1994issue of the American Math-ematical Monthly, psycholo-gist and engineer Bela Juleszlooked through a stereoscopeat two aerial photographs ofcamouflaged areas taken fromslightly different angles. Henoted that previously hiddentanks seemed to jump out.Julesz determined that depthperception did not take placein the eye but at a higher placein the brain.

In 1979 a former student ofJulesz’s, Christopher W. Tyler,created the single-picture ste-reogram, akin to the oneshown here. Such images didnot need the stereoscope; witha little training, eyes couldfind the hidden three-dimen-sional picture.

To see what all the hoopla isabout, just cross your eyes un-

til the two black dots above this image become four. Then,through luck or will, make the two central dots of your hal-lucination coalesce, until only three spots remain. Take anaspirin. Focus on the middle dot. When it is clear and un-moving, slowly bring your eyes down over the picture. Youshould see parts of the image bending concavely in theform of two marine mammals—unless you are part of the2 percent of the population that is stereoblind. Of course,it may be simpler to just hang out of a helicopter and lookfor camouflaged army equipment. —Marguerite Holloway

Secrets in Stereogram

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Copyright 1994 Scientific American, Inc.