Science: Disk with a cast of thousands: Digital imaging and its offspring, the electronic picture library, are making their mark in widely divergent fields, says Bernadine Coverley

SEEING is believing when a director is looking for just the right cast for his or her next production. Instead of poring over Spotlight, the theatrical world's directory, producers and casting directors can now key in their requirements to Showbase, UK, a casting database set up in Britain two years ago.

Lorne Magory, one of the founders, demonstrates: 'Say we need a young actress, a French speaker with fencing skills, aged between 18 and 30' - and up comes a list of 17 suitably qualified candidates. Select one, and at the touch of a space bar her image appears on screen and can be printed out.

Electronic picture libraries such as Showcase are easily possible with digital image handling and the storage capability of the laser disk, but they are only now creeping into common use. As with textual information, access to an electronic picture library is immeasurably quicker than taking out a book or file, checking the index and turning pages. Stills can be searched and put up for comparison and the advent of Sony's pocket-sized CD Rom electronic book, which costs about pounds 350, means that wherever you are you can look at, read and listen to recorded information. 'If I were an agent in the Beverly Hills Hotel, I could run through a database on my Discman and pull up photos for a casting meeting or audition shortlist, just like that,' says Mr Magory, who is also a television producer.

Mr Magory and his partner, Christopher Lapina, combine the creative and the technical, Mr Magory with his experience as a director and producer, and Mr Lapina with his information technology consultancy and sound engineering background. They developed Showbase and built up a clientele that has casting directors on one side and 3,000 entertainers on the other, and includes advertising agencies such as Ogilvy & Mather. With voice-overs added to the package and a growing number of photos that can be reproduced on screen, they feel confident enough to promote their product in the United States.

The partners also plan to expand into Europe. Mr Magory explains: 'It will never replace auditions, but with more and more European co-productions, making a shortlist will be a lot easier. Information needs to travel so fast that this will really score. Eventually, there will be phone-link access to photos, although now we send a disk that is updated every two weeks.'

Their experience illustrates the fact that quality image reproduction on disk, as opposed to film or video, has only recently been taken up outside broadcasting companies. Images need a lot more electronic storage space than text and the cost used to be about 25p per picture. Now it is cheaper and data can be compressed into a small space through optical disk storage. Thousands of pictures can be stored on an optical disk, and with digital imaging the quality will not diminish.

Large broadcasting companies have been pioneering the use of digital imaging for some years. TVS was the first customer for a system called Gallery 2000, from Logica Space and Communications Ltd, which manages 50,000 pictures with a four-second retrieval. The BBC has had an electronic file of stills, Slidefile, on several sites. Austrian Broadcasting stores thousands of pictures accessible to news journalists and programme-makers in all parts of the building with one-second recall. In such big institutions the technology that allows television news journalists to access and compare stills directly has long been more cost-effective than sending someone running down corridors to and from a library.

Not all broadcasting initiatives are successful, however. The BBC's own electronic directory of actors, called Lasercast, was finally laid to rest six months ago, after several management buyouts and three years of effort. But when technical developments are accompanied by lower prices, organisations as diverse as art galleries and local police authorities get interested. Police have been testing out databases for mugshots, and art and authority meet when reference is needed for insurance and identification of stolen art and antiques. The National Art Library at the Victoria & Albert Museum in London started a section for CD Rom and video discs two years ago. A program called Impressionism, for example, published in 1991, has a sophisticated search facility that allows researchers or art historians to find paintings by subject, owner, gallery, title or artist.

Douglas Dodds, the head of collection management at the NAL, says: 'We have a long-term obligation to acquire art publications as records.' He speaks enviously of the National Gallery in Washington's CD Rom publishing ventures. Fans of Marilyn Monroe can gaze on every image recorded by artists with a quick search through Notable Americans, a CD Rom released in 1990.

The videodisc, an earlier system on the Apple Macintosh, provides a higher-quality image and includes stills and video sequences. One 30-minute videodisc, Vienna, contains 15,000 still pictures and motion footage plus English and German sound-tracks. A selection of stills can be compiled from the material to make a slide-type presentation and can be printed out if needed.

The Vasari laboratory system takes the possibilities of electronic manipulation of paintings a step further than simple record-keeping for researchers. Since the original research project, which was funded by the European Commission and completed this year, the art world has taken up the challenge of digitisation. The National Gallery in London is using Vasari in scientific analysis to improve techniques in the conservation and restoration of paintings, and Birkbeck College in London has established an MA in art history and computing.

The Micro Gallery in the Sainsbury wing of the National Gallery is perhaps the best-known electronic picture library system. Neil Aberdeen, a spokesman, says: 'The impetus for our Compact Disc Interactive and CD Rom publishing plans came from having such an important computer resource.' The Design Museum in London also has a catalogue of its collection on CD Rom allowing searches for name, period and style.

Rama - remote access to museum archives - is the next development in electronic imaging supported by the European Commission. The Victoria & Albert Museum, with seven million objects to record, is assessing the possibilities of a disk catalogue.

(Photograph omitted)