rle_region op• Data kinds: rle_region → measurement
• Call: import fullseye as fs; fs.ledger.vol_rle_volume(region) -> 'int' (to call the implementation directly, import volregion; volregion.vol_rle_volume(region) -> 'int'; from the registry, ops3d.get("vol_rle_volume"))
Voxel count of the region, computed on the runs (no decode).
Measured ~300x faster than summing the dense mask.
Computation: sum(ends - starts) (the differences are taken in int64, so it does not overflow even with many runs). The return value is a Python int (voxel count, unit = voxel. If you want physical volume in mm^3, multiply by the spacing product sz*sy*sx yourself — this op does not accept spacing).
The input is validated with _require_rle before use (not a VolRLE, inconsistent shape or run arrays, out-of-range runs raise ValueError). An empty region returns 0 (not treated as an error). The purpose is to return the same value as vol_rle_decode followed by sum(), without building a dense array. Applying it to each component of vol_rle_components gives the per-component volume.
• 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.
• rle_region_efficiency — py -3.11 examples_3d/rle_region_efficiency.py
measurement as input)vol_gaussian_psf · fuse_to_voxel · fresnel_reflectance · snell_angle
rle_region)vol_rle_encode · vol_rle_decode · vol_rle_bbox · vol_rle_centroid · vol_rle_union · vol_rle_intersect · vol_rle_difference · vol_rle_components
*Provenance: volregion.py — 3D 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.