The count-rate correction clips an over-range pixel to Count_cutoff rather than
marking it - "if the observed rate exceeds the corresponding observed cutoff
rate, the corrected rate is set to the cutoff rate", Trueb et al. (2015)
J. Synchrotron Rad. 22, 701-707 - so the cutoff is a value a pixel can hold and
the limit is exclusive. It is not an NXmx saturation_value, which states the last
VALID count and keeps its +1.
Three of the miniCBF sets in the corpus carry a clipped pixel in every frame:
isolated, in flat background, at exactly the cutoff, with the next-highest count
in the image a tenth of it. Those pixels were integrated as valid measurements.
Only pixels exactly at the cutoff change: 0-2 per frame in 3 of ~30 sets, none in
any EIGER-written CBF, and no set has a pixel within 100 counts below it.
XDS and DIALS read the field as the last valid count and pass such a pixel
through; imgCIF's own overload item states the valid values are those below it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013nW6FNRP1bBJJ8pfHiByAT
leonarski_fandClaude Opus 5
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