One way to precisely align is to place markers, or tags, around the site. We’ve designed “ChromaTag” (above) that can be detected more accurately and 10x to 50x faster than existing markers. The key is to encode the pattern for detection and identification within the “A” and “B” channels of the CIE L*a*b color space. Because the colors aren’t often seen next to each other in natural scenes, the tag can be detected very quickly, while detectors for colorless tags have to spend a lot of time sorting through t
Source: What AI Can Do for Progress Monitoring – Reconstruct Inc – Medium