Enum: DefacingMethodEnum

Approaches to pixel-level de-identification that remove or obscure facial features in head imaging. Skull-stripping removes all non-brain tissue and may discard useful anatomy; face-specific methods aim to remove only facial features while preserving as much of the head volume as possible.

URI: valuesets:DefacingMethodEnum

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Permissible Values

Value	Title	Description	Applicable To	Example Tools	Preserves Skull
SKULL_STRIPPING	Skull stripping	Removal of all non-brain tissue including scalp, skull and face, for example with FSL BET or AFNI 3dSkullStrip			false
TEMPLATE_BASED_MASKING	Template-based masking	Registration of the image to a standard brain template such as MNI152 followed by application of a predefined binary face mask that zeros out facial voxels		PyDeface, FreeSurfer mri_deface, mydeface	true
SURFACE_BLURRING	Surface blurring	Diffusion or blurring of face surface voxels to obscure identity while preserving head shape, as in Milchenko and Marcus (2013)			true
SHEARING_PLANE	Shearing plane	Removal of the front of the head by computing a plane through the head and discarding voxels in front of it, as in QuickShear			partial
DEEP_LEARNING_SEGMENTATION	Deep learning segmentation	Use of a trained neural network such as a 3D U-Net to segment facial features (eyes, ears, nose) and mask or blur them		DeepDefacer, Asan Defacer	true
REFACING	Refacing	Replacement of the subject's face with an average or synthetic face so that images retain a realistic head surface		AFNI refacer	true
MANUAL_MASKING	Manual masking	Interactive painting or erosion of a face mask in an image editor such as 3D Slicer or ITK-SNAP, followed by zeroing or blurring of masked voxels			true
FACE_DETECTION_AND_BLURRING	Face detection and blurring	Frame-by-frame detection of faces in 2D images or video followed by blurring, pixelation or masking, for example with OpenCV Haar cascades	photographs, video
MANUAL_CROP_OR_BLUR	Manual crop or blur	Manual cropping or blurring of the face region in photographs or video with an image or video editor	photographs, video

Slots

Name	Description
defacing_method	The method used to remove facial features from image pixel data

Identifier and Mapping Information

Schema Source

from schema: https://w3id.org/valuesets

LinkML Source

name: DefacingMethodEnum
instantiates:
- valuesets_meta:ValueSetEnumDefinition
description: Approaches to pixel-level de-identification that remove or obscure facial
  features in head imaging. Skull-stripping removes all non-brain tissue and may discard
  useful anatomy; face-specific methods aim to remove only facial features while preserving
  as much of the head volume as possible.
title: Defacing Method
from_schema: https://w3id.org/valuesets
contributors:
- orcid:0000-0002-6601-2165
- https://github.com/anthropics/claude-code
status: DRAFT
rank: 1000
permissible_values:
  SKULL_STRIPPING:
    text: SKULL_STRIPPING
    description: Removal of all non-brain tissue including scalp, skull and face,
      for example with FSL BET or AFNI 3dSkullStrip
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'false'
    title: Skull stripping
    aliases:
    - brain extraction
  TEMPLATE_BASED_MASKING:
    text: TEMPLATE_BASED_MASKING
    description: Registration of the image to a standard brain template such as MNI152
      followed by application of a predefined binary face mask that zeros out facial
      voxels
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'true'
      example_tools:
        tag: example_tools
        value: PyDeface, FreeSurfer mri_deface, mydeface
    title: Template-based masking
  SURFACE_BLURRING:
    text: SURFACE_BLURRING
    description: Diffusion or blurring of face surface voxels to obscure identity
      while preserving head shape, as in Milchenko and Marcus (2013)
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'true'
    title: Surface blurring
  SHEARING_PLANE:
    text: SHEARING_PLANE
    description: Removal of the front of the head by computing a plane through the
      head and discarding voxels in front of it, as in QuickShear
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: partial
    title: Shearing plane
    aliases:
    - cropping plane
  DEEP_LEARNING_SEGMENTATION:
    text: DEEP_LEARNING_SEGMENTATION
    description: Use of a trained neural network such as a 3D U-Net to segment facial
      features (eyes, ears, nose) and mask or blur them
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'true'
      example_tools:
        tag: example_tools
        value: DeepDefacer, Asan Defacer
    title: Deep learning segmentation
  REFACING:
    text: REFACING
    description: Replacement of the subject's face with an average or synthetic face
      so that images retain a realistic head surface
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'true'
      example_tools:
        tag: example_tools
        value: AFNI refacer
    title: Refacing
  MANUAL_MASKING:
    text: MANUAL_MASKING
    description: Interactive painting or erosion of a face mask in an image editor
      such as 3D Slicer or ITK-SNAP, followed by zeroing or blurring of masked voxels
    annotations:
      preserves_skull:
        tag: preserves_skull
        value: 'true'
    title: Manual masking
  FACE_DETECTION_AND_BLURRING:
    text: FACE_DETECTION_AND_BLURRING
    description: Frame-by-frame detection of faces in 2D images or video followed
      by blurring, pixelation or masking, for example with OpenCV Haar cascades
    annotations:
      applicable_to:
        tag: applicable_to
        value: photographs, video
    title: Face detection and blurring
  MANUAL_CROP_OR_BLUR:
    text: MANUAL_CROP_OR_BLUR
    description: Manual cropping or blurring of the face region in photographs or
      video with an image or video editor
    annotations:
      applicable_to:
        tag: applicable_to
        value: photographs, video
    title: Manual crop or blur