Categorical Mask and Spatial Label Refinement R package fibermargin version 0.1.0 Implements 'FiberMargin', a deterministic training-free operator for repairing categorical masks and spatial labels from coordinates and labels alone. Its primary multiclass operator uses rotated space-filling-curve charts and two-sided class enclosure at one fixed geometric transport range. A class-balanced, isolation-protected chart-disagreement rule provides pointwise repair decisions and audit scores. An auxiliary nearest-neighbour ballot handles binary masks. The 'C++' engine supports two- and three-dimensional coordinates, removes constant axes independently within each specimen, and reuses one deterministic CPU worker budget without nested process pools. Reproducible mask corruptions, planar and volumetric simulators, damage-aware evaluation, and compact licensed human dorsolateral prefrontal cortex and colorectal cancer benchmarks support assessment. Software Depends: R (>= 4.1.0) Imports: Rcpp, parallel LinkingTo: Rcpp Suggests: testthat (>= 3.0.0), ggplot2, dplyr, tidyr, knitr, rmarkdown Stefano Cacciatore <tkcaccia@gmail.com> Comprehensive R Archive Network (CRAN) Stefano Cacciatore [aut, cre, cph] MIT + file LICENSE (https://CRAN.R-project.org/package=fibermargin/LICENSE) 2026-09-18 application/tgz https://CRAN.R-project.org/package=fibermargin doi:10.32614/CRAN.package.fibermargin