I worked for a number of years on making invisible fiducials that can appear only in infrared, and am one of the chief inventors on 3M's smart code. The idea was that on any retroreflective surface you can place this fiducial sticker and relay some information. We were originally looking at approximately 64 bits of information. This isn't a ton, but we thought it a good balance of error correction, and module (the pixels in the code) size.
At least from an IR perspective, it was generally loved by nearly everyone we spoke to, but there was no takers in the end due to the IR requirement and such cameras not being everywhere yet.
Here is a link to some of our first work. That picture of a stop sign is our first prototype with hand cut special film.
At least from an IR perspective, it was generally loved by nearly everyone we spoke to, but there was no takers in the end due to the IR requirement and such cameras not being everywhere yet.
Here is a link to some of our first work. That picture of a stop sign is our first prototype with hand cut special film.
https://www.businessinsider.com/3m-hides-tech-in-sides-to-he...