Human Computer Interaction

Tobias Appel

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University of Tübingen
Dpt. of Computer Science
Human-Computer Interaction
Sand 14
72076 Tübingen

+49 - (0) 70 71 - 29 - 75458
+49 - (0) 70 71 - 29 - 50 62
Sand 14, C205a
Office hours
on appointment

Research Interests

  • Eye-tracking applications in psychological research
  • Machine learning
  • Computer vision
  • Cognitive load detection
  • Eye tracking and self-regulation
  • Blink detection



CBF:Circular binary features for robust and real-time pupil center detection

by W. Fuhl, D. Geisler, T. Santini, T. Appel, W. Rosenstiel, and E. Kasneci

In ACM Symposium on Eye Tracking Research & Applications, 2018.


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Brightness- and Motion-Based Blink Detection for Head-Mounted Eye Trackers

by T. Appel, T. Santini, and E. Kasneci

In ACM International Joint Conference on Pervasive and Ubiquitous Computing: Adjunct publication – PETMEI 2016, 2016.


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Blink Detection

Blinks are an indicator for fatigue or drowsiness and can assist in the diagnose of mental disorders, such as schizophrenia. Additionally, a blink that obstructs the pupil impairs the performance of other eye-tracking algorithms, such as pupil detection, and often results in noise to the gaze estimation. The algorithm presented here, is tailored towards head-mounted eye trackers and is robust to calibration-based variations like translation or rotation of the eye. The proposed approach reached 96,35% accuracy for a realistic and challenging data set and in real-time even on low-end devices, rendering the proposed method suited for pervasive eye tracking.

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Course Term
Seminar: Advanced Topics in Perception Engineering Summer 2019