blob_select — BLOB select op

• Data kinds: labels2d → labels2d

• Call: import fullseye as fs; fs.ledger.blob_select(labels: 'Any', feature: 'str', vmin: 'Optional[float]' = None, vmax: 'Optional[float]' = None, spacing: 'float' = 1.0) -> 'np.ndarray' (to call the implementation directly, import blob2d; blob2d.blob_select(labels: 'Any', feature: 'str', vmin: 'Optional[float]' = None, vmax: 'Optional[float]' = None, spacing: 'float' = 1.0) -> 'np.ndarray'; from the registry, opsblob.get("blob_select"))

Usage

Keeps only the objects whose feature value lies in [vmin, vmax] (the numbers are reassigned starting from 1).

Parameters

labels : array_like

Output of blob_label.

feature : str

One of FEATURE_KEYS. An unknown key is rejected, with the candidates listed.

vmin, vmax : float or None

Both ends (inclusive). None leaves that side open. Both None means

"nothing selected" and is rejected -- if you intend to pass everything, just do not call it.

spacing : float

Same meaning as in blob_features. Needed when cutting area or perimeter

in physical units.

Returns

numpy.ndarray

int32 label image. The surviving objects are renumbered consecutively 1..k

(the original numbers are not kept). If you need the original numbers, take

blob_features(labels)["label"] beforehand.

Detailed usage guide

• blob_analysis 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_particle_sizing — py -3.11 examples/poc_particle_sizing.py

• poc_pipe_wall_loss — py -3.11 examples/poc_pipe_wall_loss.py

• poc_pv_thermal_survey — py -3.11 examples/poc_pv_thermal_survey.py

• poc_solar_el_inspection — py -3.11 examples/poc_solar_el_inspection.py

• poc_weld_radiograph_porosity — py -3.11 examples/poc_weld_radiograph_porosity.py

Ops the type connects to (they accept labels2d as input)

blob_features · blob_select_largest · blob_split · blob_region · blob_boundaries · blob_overlay

Same category (select)

blob_select_largest


*Provenance: blob2d.py — BLOB 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.