3 ms·

There isn't a combination of laser scanning and/or structured light projection scanning that can accomplish this? Or is it a speed/quality control issue of the

• joshvm 10y ago
  Triangulation laser scanning is about the closest you get in terms of accuracy. It can work on virtually any surface, including specularly reflective ones (I've worked on bespoke systems for the steel industry). It's accurate down to microns, but the usual problem is the field of view sucks - either you go further away and sacrifice resolution or you go really close and accept that you need to move the scanner (or object) around a lot. For small things, it's fine. You put your doodad on a turntable. For cars, forget it. Stereo structured light is great, but doesn't work on specularly reflective objects. You've seen those amazing depth maps from the guys at Middlebury? Wonder how they get perfect ground truth on motorbike cowls that are essentially mirrors? Well they have to spray paint them grey so that you can see the light. The next problem is that you're limited by the resolution of the projector (so I guess if you own a cinema, yay!) and the cameras. Then you have to do all the inter-image code matching which sounds trivial in the papers, but in practice a lot harder (and since you don't get codes at all pixels you need to interpolate, etc, etc). There are handheld scanners like the Creaform which work pretty well on small things, but I don't know what the accuracy is like. The ultimate system would probably be a high-resolution, high-accuracy, scanned LIDAR system. Then you lose the problems with scanning ranges/depth of field, but you accept massively higher cost and possibly a much longer scan time for accurate systems.