Ask HN: 2D Spread-spectrum signal in an advert?

I can remember a company launching an advertising scheme in the late 90's, which involved overlaying a spread spectrum signal on a standard advert, to be printed in magazines. The idea was that readers would point their webcams at the page, for their browser to be directed to a relevant site in a similar fashion to how QR codes are used today. It was evidently way ahead of its time, and it sank apparently without a trace in the dot-com bloodbath.

To be clear, this was not a separate, black-and-white barcode on its own in a corner, it was a pseudorandom overlay across the entire page which, as I recall, was only slightly visible, and didn't overly affect the image quality.

I'm interested in how this technology was implemented (specifically what trade-offs they made with respect to transformations and distortions), but my usual sources have failed me. Can anyone recall what the company or the technology were called? It wouldn't surprise me if they'd tried for a patent, but whether it would have been granted or not is another matter.