v0.16.3

BasisSimulator v0.16.3

Diff since v0.16.2

Fixed

• Ring artifacts of the realistic photon-counting detector. Defects are gain and threshold spreads, as in NAEOTOM_ALPHA. In noise-free images against the ideal detector, the rings fall from up to 168 HU to under 0.6 HU.
• calibrate_flat_field for a photon counter with defects now also scans water slabs, every 5 cm from 5 to 50 cm. It divides each pixel's scan of a slab by the nominal detector's scan of it, a per-pixel spectral calibration. apply_flat_field! then corrects each ray at its own line integral. FlatFieldCalibration gains a hardening field.
• The photon-counting defect model now depends smoothly on hardening, from 0 to 50 cm of water. It used to be clamped at 40 cm.
• The pile-up correction's table is finer.

Every result of a photon counter with defects changes. The ideal detector's results are unchanged. See CHANGELOG.md.

Merged pull requests:

• Docs for v0.16.2: the 12 BasisSimulator notebooks re-rendered; CI test jobs get 300 minutes (#85) (@Dale-Black)
• v0.16.3: a photon-counting flat field through water slabs; the realistic unit does not ring (#86) (@Dale-Black)