card-scale · spike

Measure it with a card.

Put any bank card flat on the surface you want to measure — a dishwasher door, a cabinet opening. One photo, and the card's exact 85.6 mm size turns pixels into millimetres.

  1. 1 Lay a card flat on the surface.
  2. 2 Shoot it straight-on, filling the frame.
  3. 3 Tap two points — get the distance in mm.

Starting camera…
0 in set
Detecting card…

Photo set

These frames are staged for the phase-2 GPU reconstruction (VGGT / MapAnything). The card in the set gives the metric scale; the backend returns depth.