Alan Cane's essay in the January 30, 2008 Financial Times about the coming convergence of photorealistic imagery with "reality" was most interesting, especially the final sentence, which read: "But it may be necessary for governments at some stage, and using technologies as yet undiscovered, to limit the extent to which computer-generated images can be presented as reality on our many screens."

Here's the FT piece.

Will we be able to tell reality from artificial imagery?

There is one cast-iron certainty in what is becoming a hazy technological future: the image — and the screen on which it is displayed — will increasingly become king.

On television screens, on personal computers, on digital organisers, on games consoles, telephones and music players, computer generated images of startling realism — animated and in three dimensions — will increasingly become the norm.

By comparison, today's images — excellent though they can be - will appear as dated as the daguerreotypes of the 19th century.

On the one hand, this is progress. A picture may be worth a thousand words - indeed it certainly is worth a thousand words when you are trying to work out how to insert a new ink cartridge into a printer.

On the other hand, this level of photorealism will bring with it a slew of problems with which governments will be forced to deal.

The rate of progress in rendering realistic three dimensional computer generated images over the past few years is remarkable.

The technologies have found application both in feature films, such as the recent release, Bee Movie, and in advertising. "Naturally Juicy", a "strangely saucy" (their words, not mine) advert for Orangina involving a bear and a deer in a forest is the latest creation by The Mill, a London-based post production house which has been making a habit of picking up awards.

For one minute and 45 seconds of screen time, The Mill's 30 animators took three months to bring a galaxy of characters including a flamingo pole-dancer, a bikini-clad rabbit and an octopus waitress to life.

Tellingly, the greatest challenge the animators faced was rendering fur and feathers realistically. Ten years or so ago, it would not have been possible to create such life-like images

The pace has been forced, however, by a couple of critical developments. First, graphics processing units (GPUs) have become incomparably more powerful.

GPUs are processor chips which work in conjunction with the central processor but are designed wholly to carry out the complex mathematics required, for example, accurately to convey the texture of skin, hair or moving water. The market for GPUs is currently dominated by Nvidia, which fabricates the GeForce graphics chip family, and by AMD which makes the ATI Radeon chip line.

A second innovation, pioneered by Nvidia but quickly followed by AMD, was programmable pixel shading, which made it possible to process each individual picture element. This enables the animator to treat each pixel separately and to come closer to mimicking reality. A moving, bumpy, reflective surface can be rendered by pixel shaders in ways which would have been impossible using earlier technology.

There have been other, startling, developments. Henrik Wann Jensen of the University of California at San Diego is an expert in developing images in which light interacts with other materials - the patterns of light and shade created as sunlight filters through a glass of brandy, for example.

Now, he has built a mathematical model based on the absorbtion and reflection of light which can create the image of a material when given its constituents. And it works in reverse: given an image, the software will work out what it is made of.

There are, nevertheless, a number of constraints on the development of three dimensional computer generated imagery, not the least of which is the limited number of skilled craftspeople capable of working with these advanced tools.

The Mill and its London competitors, the US post production world and the GPU manufacturers are all in competition for these individuals. They are often freelance, travelling the world and selling their services when an interesting project presents itself.

The fact that it took about 2,000 hours to produce two minutes of final product for the Orangina advert is another hurdle. The new tools seem to have vastly increased the quality of the final image but have not significantly reduced the time taken to create it.

The upside, therefore, is computer-generated movies indistinguishable from conventionally shot films and computer games where there seems to be no line between real life and fantasy.

The downside is whether we are ready for this degree of photorealism on the screens that will increasingly dominate our lives. A computer game today, however violent, is still clearly a game. The advent of shoot-'em-ups indistinguishable from real life could keep researchers working on the effects of computer games on social behaviour busy for years.

Second Life and other metaverses are again, today, obviously crude imitations of the real thing. What would be the consequences of a Second Life that seemed as real as real life — or at least as real as the television images that we take for granted as representing reality.

One senior figure in the games industry suggested to me in all seriousness that at some date in the future, news events would no longer be filmed live — they would be created wholly in the computer.

The consequences for society are difficult to predict. But it may be necessary for governments at some stage, and using technologies as yet undiscovered, to limit the extent to which computer-generated images can be presented as reality on our many screens.

At first I thought maybe I didn't get the joke about how governments would censor the photorealistic imagery indistinguishable from "reality."

Then I chuckled, knowing that computer-savvy people around the world were laughing out loud and falling off their chairs at the thought.

Not very likely, that apparently wishful thinking of Cane.

Far more likely is William Gibson's vision of the future, where computer-generated media interact seamlessly with the "real world," fusing to take us to the place we're all destined to inhabit in the coming decades.