PathML
Scope and safety boundary
Use PathML for local computational pathology research. It is beta research software, not a validated medical device, diagnostic system, clinical decision support tool, or substitute for a pathologist. Do not use outputs to diagnose, grade, stage, or treat a patient.
Pathology files may contain faces, labels, accession numbers, patient identifiers, DICOM tags, filenames, or linked clinical data. Before processing:
- Confirm authorization, consent/waiver, data-use terms, and institutional policy.
- De-identify pixels and metadata; keep the re-identification key outside the analysis workspace.
- Use pseudonymous
patient_id,slide_id, andspecimen_idvalues. Do not put direct identifiers in filenames, logs,.h5pathlabels, model cards, or reports. - Keep inputs, intermediates, and outputs on approved local encrypted storage.
- Split by patient (then slide) before tiling or fitting any preprocessing step.
Version baseline, verified 2026-07-23
- Installable stable release: PyPI
pathml==3.0.5, published 2026-03-24. - The v3.0.5 release notes state Python 3.10-3.12 and sunset 3.9.
PyPI does not declare
Requires-Pythonand still has a stale 3.8 classifier, so use the release statement and test the exact environment. - GitHub releases v3.0.6 (2026-04-14) and v3.0.7 (2026-07-09) exist, but PyPI has no artifacts for them as of this review. v3.0.7 updates Torch/TorchVision/ torch-geometric and ONNX export code. Do not mix those source dependencies with the 3.0.5 wheel.
- ReadTheDocs
/latestidentifies itself as 3.0.5. Examples here were checked against the v3.0.5 tag and PyPI wheel metadata, not unversioned snippets. - This skill is MIT-licensed. PathML itself is GPL-2.0 with upstream commercial licensing options; review upstream terms before redistribution.
Reproducible installation
Use Python 3.11 unless the project has tested another supported interpreter:
uv venv --python 3.11
source .venv/bin/activate
uv pip install "pathml==3.0.5"
python -c "import importlib.metadata as m; print(m.version('pathml'))"
PathML 3.0.5 declares no package extras: do not use pathml[all]. Its base
distribution pins a large scientific/ML stack, including Torch 2.8.0, ONNX 1.17.0,
ONNX Runtime 1.17.x, OpenSlide Python 1.3.1, python-bioformats 4.1.0, and
python-javabridge 4.0.4.
Install native prerequisites before the uv command:
# Debian/Ubuntu
sudo apt-get install openslide-tools gcc g++ libblas-dev liblapack-dev openjdk-17-jdk
# macOS
brew install openslide openjdk@17
# Windows OpenSlide option documented upstream
vcpkg install openslide
Java/Bio-Formats is needed for the broad multidimensional format backend.
OpenSlide handles common brightfield WSI formats more efficiently. CUDA is
optional and must match the pinned PyTorch build; follow PyTorch's platform
selector rather than guessing a CUDA wheel. See references/image_loading.md.
Stable minimal workflow
PathML 3.0.5 uses slide convenience classes and SlideData.run(). It does not
provide SlideData.from_slide(), and Pipeline does not have run():
from pathml.core import HESlide
from pathml.preprocessing import BoxBlur, Pipeline, TissueDetectionHE
slide = HESlide("data/pseudonymous_slide.svs", backend="openslide")
pipeline = Pipeline(
[
BoxBlur(kernel_size=5),
TissueDetectionHE(mask_name="tissue", min_region_size=5000),
]
)
slide.run(
pipeline,
distributed=False,
tile_size=512,
tile_stride=512,
level=0,
tile_pad=False,
)
slide.write("derived/pseudonymous_slide.h5path")
Start with a bounded manual sample before a full run:
from itertools import islice
for tile in islice(slide.generate_tiles(shape=512, stride=512, level=0), 8):
pipeline.apply(tile)
assert tile.masks["tissue"].shape[:2] == tile.image.shape[:2]
Tiles use (i, j) = (row, column) coordinates at the selected pyramid level.
For OpenSlide, PathML maps them to level-0 coordinates internally. Record the
level and downsample; convert to (x, y) or micrometres explicitly downstream.
Research workflow
- Inventory locally. Validate the manifest, reject URLs/symlinks, inspect only allowlisted technical metadata, and remove identifiers.
- Freeze splits. Assign every patient and all their slides to one split before generating overlapping tiles, graphs, normalization references, or features.
- Plan bounds. Estimate tile count, RAM, output size, and pipeline stages.
- Pilot preprocessing. Inspect tissue masks, whitespace/artifact labels, stain behavior, edge padding, and empty-mask cases on representative training slides. Do not tune from test slides.
- Run and preserve coordinates. Keep tile level,
(i, j), downsample, MPP, mask names, QC decisions, and failed/skipped tiles. - Build spatial data deliberately. Validate channel order, physical units, instance labels, node-feature alignment, graph edges, and cell-to-tissue assignments.
- Infer in bounded batches. Verify model provenance and checksum without loading unknown pickle checkpoints. Keep predictions linked to slide/tile coordinates and stitch overlaps with a documented rule.
- Report provenance and limits. Include package lock, source hashes, scanner, stain, parameters, seeds, split manifest, model card, exclusions, and QC.
No-network default and explicit consent gate
Do not instantiate download-capable classes or set dataset download=True unless
the user explicitly opts in after receiving the endpoint and disclosure:
SegmentMIFRemotedownloads an ONNX file fromhttps://huggingface.co/pathml/test/resolve/main/mesmer.onnxat construction, then runs inference locally. Stable source does not upload image pixels. The request still discloses network metadata such as IP address and headers and createstemp.onnx; there is no built-in checksum or offline flag.- Deprecated
SegmentMIFimports local DeepCell Mesmer, but DeepCell model initialization may need separately provisioned weights. It is not a PathML extra and is not the preferred stable API. RemoteTestHoverNetdownloads a model from Hugging Face.PanNukeDataModule(download=True)contacts Warwick;DeepFocusDataModulecontacts Zenodo. Both default todownload=False.
Before any future hosted prediction call, state the exact destination, pixel channels/regions, metadata, identifiers, retention, legal basis, and safeguards; obtain explicit consent; and never send PHI by default. Prefer reviewed, checksummed local model artifacts and local inference.
Model-code security
- PyTorch
model.eval()means evaluation mode for modules; it is not Python's dangerous built-in evaluator. Never use Python dynamic evaluation or execution. - Do not name local files
pathml.py,torch.py,onnx.py, or after standard libraries; shadow modules can silently change imports. - PathML's
EntityDatasetloads.ptobjects withweights_only=False. Never open an untrusted graph/checkpoint. Treat pickle-based pipelines and.ptfiles as executable code. - ONNX is safer than pickle but not inherently trusted. Verify source, SHA-256, expected input/output schema, file size, and runtime limits; use isolation for third-party models.
Bundled local CLIs
All helpers reject URLs and symlinks, cap inputs/work, use strict JSON, avoid
network access, and require no PathML import for --help:
python scripts/slide_manifest.py validate --manifest manifest.csv --root .
python scripts/slide_manifest.py inspect --slide data/example.svs --root .
python scripts/plan_pipeline.py --width 100000 --height 80000 --tile-size 512 --stride 512
python scripts/image_qc.py synthetic --width 256 --height 256
python scripts/validate_spatial_schema.py graph --input graph.json --root .
python scripts/validate_spatial_schema.py multiplex --input cells.csv --root .
python scripts/plan_inference.py --tile-count 4000 --batch-size 16 --height 256 --width 256
The inference planner reads numbers or a bounded JSON model card only; it never imports a model framework or opens a checkpoint.
Detailed references
references/image_loading.md— slide classes, backends, formats, levels, coordinates, technical metadata, and privacy.references/preprocessing.md— stable transforms, masks/QC, stain processing, pipeline execution, and leakage prevention.references/data_management.md—.h5path, manifests, datasets, provenance, splits, and safe downloads.references/multiparametric.md— multidimensional layout, CODEX/Vectra, quantification, AnnData, DeepCell/Mesmer, and network disclosure.references/graphs.md— instance maps, feature alignment, KNN/RAG/HACT graphs, spatial units, schemas, and validation.references/machine_learning.md— HoVer-Net/HACTNet, local ONNX inference, batching, checkpoint trust, evaluation, and model provenance.
Primary sources
All checked 2026-07-23:
- PyPI metadata: https://pypi.org/project/pathml/3.0.5/
- Stable source tag: https://github.com/Dana-Farber-AIOS/pathml/tree/v3.0.5
- Releases: https://github.com/Dana-Farber-AIOS/pathml/releases
- Stable documentation: https://pathml.readthedocs.io/en/stable/
- Rosenthal et al. (2022), PathML toolkit: https://doi.org/10.1158/1541-7786.MCR-21-0665
- Omar et al. (2025), multiplex workflows: https://doi.org/10.1016/j.labinv.2025.104220