seg_label_changes — EMPROOF inject op

• Data kinds: labels2d × labels2d → table

• Call: import fullseye as fs; fs.ledger.seg_label_changes(before, after, min_pixels: 'int' = 1, ignore_zero: 'bool' = True) -> 'dict' (to call the implementation directly, import emproof; emproof.seg_label_changes(before, after, min_pixels: 'int' = 1, ignore_zero: 'bool' = True) -> 'dict'; from the registry, opsemproof.get("seg_label_changes"))

Usage

Returns the difference between two label images as pairs of merges and splits (before vs. after calibration, or checking planted errors against the answer).

Counts pairs where label b of before and label a of after share at least min_pixels of the same pixels;

• merge = 1 label of after covers 2 or more labels of before → merge_after / merge_before (1 row per pair; the id of the absorbing side itself is also listed as 1 of the before labels)

• split = 1 label of before breaks into 2 or more labels of after → split_before / split_after (likewise the id of the remaining side is also listed)

n_merged / n_split are the number of errors (counted by ids on the after side / before side). Id equality is not checked (it also works on 2 images whose labels were renumbered).

>>> ch = seg_label_changes(truth, seg_inject_merge(truth))

>>> int(ch["n_merged"])

1

Detailed usage guide

• emproof family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_em_second_opinion — py -3.11 examples/poc_em_second_opinion.py

• poc_em_split_merge_score — py -3.11 examples/poc_em_split_merge_score.py

Ops the type connects to (they accept table as input)

seg_synapse_partners · seg_wiring_variation · seg_synapse_nri · seg_wiring_exposure

Same category (inject)

seg_inject_merge · seg_inject_split


*Provenance: emproof.py — EMPROOF operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.