IEIE Summer Annual Conference 2024

Study on Facial Composite Feature Analysis for Determining Subject Anxiety Levels on Low-Power Computing Modules

저연산 컴퓨팅 모듈에서 구동 가능한 안면 복합 특성 분석 기반 대상자 긴장 상태 판단에 관한 연구

A contact-free system that reads eye blinks, pupil movement and facial expressions from an ordinary RGB camera and combines them into a single anxiety score, light enough to run on low-end hardware.

JunGyu Lee1,2 Sanghyun Alex Lee1 Gi Pyo Nam1,2
1Korea Institute of Science and Technology 2AI-Robotics, KIST School, UST

Eye-blink detection with the eye aspect ratio (EAR). Six eye landmarks give EAR per frame; a blink is counted when EAR drops below a threshold set from the subject's own mean and recovers.

Abstract

Reading anxiety from the face, without contact

Recent studies have utilized external biosignals, particularly those observable on the human face such as expressions and eye blinks, for the analysis of a subject’s level of anxiety. This paper presents the first comprehensive system for contact-free prediction of various facial features from RGB images, surpassing traditional methods reliant on prior knowledge or significant computing power. Our approach introduces modules for analyzing variations in facial features, such as eye blinks, pupil movement, and expressions, developed to operate effectively in low-end hardware environments with limited computing power. Each module has been validated on its respective benchmark dataset, demonstrating comparability with or even exceeding the State-Of-The-Art. A method for deriving a composite anxiety score based on the combination of biological signal changes is further proposed, with additional validation on a privately-conducted user study.

System

Three facial signals, one score

Each module runs on its own lightweight model so the whole pipeline fits on a low-power computing module next to the camera.

01 · Eye blinks

Blink rate from landmarks

Facial landmarks from a lightweight Pixel-in-Pixel network give six points per eye; the eye aspect ratio turns them into a per-frame openness signal and a blink count.

02 · Pupil movement

Gaze and pupil changes

Movement of the pupils between frames is analysed as a second facial signal.

03 · Expression

Facial expression recognition

A compact expression classifier reads the facial expression in every frame.

Changes in the three signals are combined into a composite anxiety score. Each module was validated on its own benchmark, and the composite score was further validated in a private user study.

Demo

Real-time blink detection on a webcam

The released eye-blink module running live: face detection, landmark localisation and a running blink count, all in real time.

The module keeps per-subject statistics of the eye aspect ratio, so the blink threshold adapts to each person instead of using one fixed value.

Because it needs only landmarks from a single RGB frame, it runs on embedded boards and plugs directly into the anxiety-estimation pipeline above.

Run it yourself

In the news

Featured in national media

The research was covered by a national newspaper and two national broadcasters, including reports on detection technology at customs.

Chosun Ilbo article: AI, reading inner feelings
Chosun Ilbo · Jul 2023AI, reading inner feelingsAI, 속마음을 읽다
MBC Newsdesk · May 2023On-site report: drugs, from inflow to distribution — can they be stopped?[현장검증] 마약, 유입부터 유통까지‥막을 수 있나?
JTBC News · D:Issue · Apr 2023Customs' cutting-edge detection technology on the front line of the “war on drugs”‘마약과의 전쟁’ 일선에 선 세관의 최첨단 탐지 기술
Cite

BibTeX

@inproceedings{lee2024facial,
  title     = {Study on Facial Composite Feature Analysis for Determining Subject Anxiety Levels on Low-Power Computing Modules},
  author    = {Lee, JunGyu and Lee, Sanghyun Alex and Nam, Gi Pyo},
  booktitle = {Proceedings of the IEIE Summer Annual Conference},
  pages     = {1816--1820},
  year      = {2024}
}