@INTERACTIONSMAG 78 INTERACTIONS JANUARY–FEBRUARY2019
FORUM INTERACTION TECHNOLOGIES
mobile-based user authentication. Proc. of
the 2017 CHI Conference on Human Factors
in Computing Systems. ACM, New York,
2017, 3751–3763; https://doi.
4. Abdelrahman, Y., Velloso, E., Schmidt, A.,
Abdelrahman, Y., and Schmidt, A.
Cognitive heat: Exploring the usage of
thermal imaging to unobtrusively estimate
cognitive load. Proc.of the ACM on
Interactive, Mobile, Wearable and Ubiquitous
Technologies 13, 3 (2017), Article 33;
5. Ioannou, S., Gallese, V., and Merla, A.
Thermal infrared imaging in
psychophysiology: Potentialities and limits.
Psychophysiology 51, 10 (2014), 951–963;
6. Vala, H.J. and Baxi, A. A review on Otsu
image segmentation algorithm.
International Journal of Advanced Research
in Computer Engineering & Technology 2, 2
Yomna Abdelrahman graduated from the
German University in Cairo in 2010. She then
earned her master’s degree in international
computer hardware and software (INFOTECH)
at Stuttgart University, Germany. She
completed her Ph.D. on thermal imaging and
novel interactive systems in the hciLab at the
University of Stuttgart. Recently she joined
University of Bundeswehr Munich as a post doc.
Albrecht Schmidt is a computer science
professor at the Ludwig-Maximilians-Universität
in Munich. He works at the intersection of
ubiquitous computing, digital media, and
human-computer interaction. His research
interests are in creating digital technologies to
augment perception and the human mind. He has
a Ph.D. from Lancaster University.
Reductions in price and size come at the
cost of resolution and thermal
sensitivity. Noncommercial thermal
cameras can detect subtle changes in
temperature (up to 0.005˚C), but while
this ability is reduced in most
commercial cameras (up to 0.04˚C), it
does not affect their potential utility.
Interestingly, although thermal imaging
operates in a different spectrum from
RGB, known computer-vision
techniques that use existing open source
libraries (e.g., OpenCV; https://opencv.
org/) work with the images generated
from thermal cameras. Additionally,
having the temperature information for
each pixel enhances existing techniques
such as person-detection, as our body
temperature can be easily extracted
from the background. Applying the
typical image-processing techniques
shown in Figure 12, different features
could be extracted, such as touch points,
facial temperature, and vein patterns.
Thermal imaging over the next 10
years. Thermal imaging has witnessed a
vast increase in application as well as
specification, where it has been involved
in HCI research, for instance, in building
novel interactive techniques. We
envision that with the DIY movement,
where sensors are commercially available
and building your own hardware
becomes more common, thermal
imaging will be further deployed in a
variety of use cases, from building
interactive systems based on thermal
imaging to replace current technologies,
to deploying it in educational settings to
monitor cognitive load, to replacing
current authentication techniques.
Furthermore, thermal cameras could be
included in all commercial smartphones,
as a feature as indispensable as current
cameras. This will open up a new field of
research in HCI, namely the implications
and privacy concerns raised by using
cameras that operate in the non-visible
1. Abdelrahman, Y., Sahami Shirazi, A.,
Henze, N., and Schmidt, A. Investigation
of material properties for thermal imaging-based interaction. Proc. of the 33rd Annual
ACM Conference on Human Factors in
Computing Systems. ACM, New York, 2015,
2. Sahami Shirazi, A., Abdelrahman, Y.,
Henze, N., Schneegass, S., Khalilbeigi, M.,
and Schmidt, A. Exploiting thermal
reflection for interactive systems. Proc. of
the 32nd Annual ACM Conference on
Human Factors in Computing Systems.
ACM, New York, 2014, 3483–3492;
3. Abdelrahman, Y., Khamis, M.,
Schneegass, S., and Alt, F. Stay cool!
Understanding thermal attacks on
DOI: 10.1145/3297778 © 2019 ACM 1072-5520/19/01 $15.00
Figure 11. Evolution of thermal cameras in terms of size and cost. Source: https://www.flir.de
Figure 10. Facial temperature captured by a
Figure 12. Thermal-image processing for
diverse features extraction [ 6].