Privacy Policy

Last updated May 2026 — see git history for all changes.

Summary

CellSeg collects no personal data. There are no analytics, no crash reporters, and no advertising SDKs in the app. The only outbound network traffic is the one-time model download and any cloud segmentation requests you explicitly initiate yourself.

Data collected

  • No personal identifiers are collected or transmitted.
  • No analytics SDK is included (no Firebase, no Mixpanel, no Amplitude, etc.).
  • No crash reporting SDK is included (no Crashlytics, no Sentry, etc.).
  • No advertising identifiers are accessed.
  • Images you capture or analyse remain on your device unless you explicitly send them to a cloud segmentation endpoint that you configure.

Network requests

Local segmentation mode

When using local segmentation (the default), no image data or metadata ever leaves your device. The only network request CellSeg makes is a one-time download of the ONNX model file (~26 MB) from the configured model host (currently a public Hugging Face repository).

After the model has been downloaded, local segmentation works entirely offline.

Cloud segmentation mode

When using cloud segmentation (Hugging Face Gradio Space), the image you are processing is sent over HTTPS to the Gradio Space you have configured.

  • Please review the Hugging Face Privacy Policy and the privacy terms of the specific Space you connect to.
  • Your Hugging Face API token (if provided) is stored in Android EncryptedSharedPreferences and is never logged or written to any storage other than that encrypted store. It is transmitted only to api.huggingface.co and your configured Space.
  • Cloud mode is opt-in and disabled by default.

File storage

All files produced by CellSeg — captured images, segmentation outputs (masks, outline PNGs, flow visualisations), metrics, and the ONNX model — are stored in app-private storage (Context.filesDir, typically /data/data/uk.yaylali.cellseg/files/).

This storage is:

  • Not accessible to other apps without root access.
  • Deleted automatically when CellSeg is uninstalled.
  • Excluded from Android Auto Backup (the app opts out to protect potentially sensitive microscopy images).

Permissions

Permission Purpose
CAMERA Capture microscopy images with the phone camera
READ_MEDIA_IMAGES / READ_EXTERNAL_STORAGE Import images from gallery or file manager
INTERNET Model download; optional cloud segmentation
WRITE_EXTERNAL_STORAGE (API ≤ 28) Export results on older Android versions

No third-party SDKs

CellSeg does not include any of the following categories of SDK:

  • Advertising (AdMob, Meta Audience Network, etc.)
  • Analytics (Firebase Analytics, Mixpanel, Amplitude, etc.)
  • Crash reporting (Crashlytics, Sentry, Bugsnag, etc.)
  • Social login or sharing

A complete list of all third-party libraries and their licences is published in the NOTICE file in the source repository.

Children’s privacy

CellSeg is a research tool intended for adult researchers and scientists. It is not directed at children and does not knowingly collect data from anyone under 13.

Changes to this policy

Material changes will be announced via a commit to PRIVACY.md in the repository. The git history provides a full audit trail of all changes.

Contact

Questions or concerns about privacy: support@yaylali.uk