Face De-Identification Model Using Virtual Identity Vectors

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Solution Overview

Problem

Existing image de-identification methods using conditional generative adversarial networks (GANs) result in poor-quality anonymized images due to the use of background pictures with face areas removed, leading to loss of identity-free attributes.

Innovation Solution

A model training method that projects training images to a target space to obtain virtual identity vectors and extracts attribute vectors, generating de-identified images based on these vectors while ensuring attribute information remains unchanged, using a projector, attribute extractor, and generator in the target network model.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If background picture with face area removed is used as model input, then identity feature removal is achieved, but image quality deteriorates

Engineering Contradiction:
Improveidentity feature removalVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent extracts only the necessary attribute information (pose, scale, background) from the original image, rather than removing the entire face area. This selective extraction preserves useful information while achieving de-identification, resolving the contradiction between identity removal and quality preservation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transforms the input representation from removed face areas to attribute vectors (pose angles, scale factors, background features). By changing the parameter representation, the model receives condensed essential information without identity features, maintaining quality while achieving de-identification.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If face area is removed from original picture, then de-identification is achieved, but attribute information is lost

Engineering Contradiction:
Improvede-identification效果VSAvoidattribute information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts specific attribute information (pose, scale, background) separately from the face area, preserving these attributes while removing only the identity-containing face region. This selective extraction prevents information loss of non-identity attributes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary extraction of attribute information before face removal. By pre-extracting pose, scale, and background attributes, the system preserves this information for later reconstruction, preventing attribute loss during the de-identification process.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If virtual identity vectors and attribute vectors are used for image generation, then image quality is improved, but model complexity increases

Engineering Contradiction:
Improvegenerated image qualityVSAvoidmodel structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the generation process into distinct components: virtual identity vector generation, attribute vector extraction, and image synthesis. This segmentation allows each component to be optimized independently, managing complexity while improving overall image quality through specialized processing for each aspect.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12494047B2Model training method and apparatus, deidentification method and apparatus, device, and storage medium
Publication Date: 2025.12.09 TENCENT TECHNOLOGY (SHENZHEN) CO LTD
  • US12494047B2 patent drawing
  • US12494047B2 patent drawing
  • US12494047B2 patent drawing

AI summary

An de-identification method includes: performing sampling on a target space of a projector in a target network model to obtain N virtual identity vectors, N being a positive integer; extracting, by using an attribute extractor in the target network model, M attribute vectors from a target image, M being a positive integer; and generating, by using a generator in the target network model, a de-identified image of the target image based on the N virtual identity vectors and the M attribute vectors.