Maybe you saw the vOICe?

Thanks for pointing me to that website. Looking at one of the pages, I think what I saw was this:

On September 16, 1998, the BBC science program Tomorrow's World featured a musical image to sound mapping devised by John Cronly-Dillon, a neurobiologist at the Department of Optometry and Vision Sciences at the University of Manchester (UMIST), UK. The broadcast showed examples in which the basic characteristics of transforming shapes into music for hearing images appeared identical to those employed by The vOICe [...] Cronly-Dillon's implementation was a computer program without live visual input, but he mentioned plans for a future portable system with a camera.

Apparently it's pretty similar to The vOICe. Both systems sound less flexible than yours could be, though, so you're probably onto a good thing here!

(You'd think the concept would be an easy sell, much like a free screen reader and electrostatic haptic displays. Of these three, only the free screen reader is catching on, and it's still more or less the Linux to Jaws' Windows.)

Yikes.