Metrology invariants (pixel-center world)

Coordinate convention

• •Integer index i corresponds to pixel center at i as f32.
• •Subpixel values are expressed in the same coordinate system.

Subpixel outputs

• •

  Always specify what x/y means in docs (center coordinates).

• •

  Provide tolerances in tests:

  • •quick unit tests: ~0.1 px is fine
  • •precision tests (later): push toward 0.05 px on higher-fidelity fixtures

Robustness

• •

  Prefer edge-pair (Rising→Falling) for laser stripes over intensity peak fitting.

• •

  If the algorithm uses an ROI around a predicted center, document:

  • •how prediction is formed
  • •what happens on gaps / reacquisition