We present HeatWave, a system that uses digital thermal imaging cameras to detect, track, and support user interaction on arbitrary surfaces. Thermal sensing has had limited examination in the HCI research community and is generally under-explored outside of law enforcement and energy auditing applications. We examine the role of thermal imaging as a new sensing solution for enhancing user surface interaction. In particular, we demonstrate how thermal imaging in combination with existing computer vision techniques can make segmentation and detection of routine interaction techniques possible in real-time, and can be used to complement or simplify algorithms for traditional RGB and depth cameras. Example interactions include (1) distinguishing hovering above a surface from touch events, (2) shape-based gestures similar to ink strokes, (3) pressure based gestures, and (4) multi-finger gestures. We close by discussing the practicality of thermal sensing for naturalistic user interaction and opportunities for future work.

1. Heatwave:
Thermal Imaging for
Surface Interaction
Eric Larson, Gabe Cohn, Sidhant Gupta
Xiaofeng Ren, Dieter Fox, Beverly Harrison
Shwetak Patel
UbiComp Lab
Design Use Build Laboratory of Ubiquitous Computing
University of Washington University of Washington Intel Research
1

2. 2

3. 3

4. LCI Interactive Floor
- 55 Merthyr Terrace, Barnes, London, SW13 8DL - Telephone: +44(0) 20 8741 5747 - Email: contact@lci-uk.com - Website: www.lci-uk.com
Intel oasis
SmartBoards
4

5. 12 34 5678
5

6. 6

7. 7

8. What is thermal
infrared imaging?
8

9. Solar Reflection Thermal Radiation
Intensity
Source
34
33
32
RGB Depth Thermal
31
30
29
28
27
26 UV Visible Near InfraredFar Infrared
25
0.1um 1um 10 um 100 um
Wavelength
9

10. $1 M
$100k
$10k
$1k
$100
$10
1940 1950 1960 1970 1980 1990 2000 2010 2020
10

11. $1 M
$100k
$10k
11

12. $1 M
1950
>$200k
1980
$100k
$10k
12

13. $100k
1991
$10k
2000
13

14. 2003 ~$2-8k
2005
2010 •30 fps
•50mK
•384x288
~$250M
14

15. 15

16. ~$50
>200 fps
2015
16

17. 17

18. $1 M
$100k
$10k
$1k
$100
$10
1940 1950 1960 1970 1980 1990 2000 2010 2020
18

19. $1 M
$100k
$10k
•30 fps
•50mK
•384x288
$1k
$100
50mK ?
$10
1940 1950 1960 1970 1980 1990 2000 2010 2020
19

20. o
~6 C
50mK levels
120
o
20 levels C
20

21. skin temperature
o
29-35 C
room temperature
o
18-26 C
21

22. 22

23. 23

24. Touch down Motion
24

25. Thermal
Camera Overhead projector
25

26. 26

27. 27

28. 28

29. 29

30. Heat Heat
Absorption Retention
Heat Transfer? 30

31. Conductivity
T
31

32. Thermal Conductivity
>100
1.1
0.4 0.5
0.04 0.23
Foam Plastic Wood Skin Glass Aluminum
32

33. Touch Release Cooling/Warming
Down Touch period
50ms 200ms 100s
Hand 34
Temperature (C)
33
Skin
32
31
30
29
28
Foam Surface
27
26
40-50s
Room 25
1ms 10ms 100ms 1s 10s 100s
Time (log scale)
Foam Plastic Wood Skin Glass Aluminum
33

34. Touch Release Cooling/Warming
Down Touch period
50ms 200ms 100s
34
Temperature (C)
33
32
31 Skin
30
29
28
27
26
Aluminum Surface
Room 25
1ms 10ms 100ms 1s 10s 100s
Time (log scale)
Foam Plastic Wood Skin Glass Aluminum
34

35. Touch Release Cooling/Warming
Down Touch period
50ms 200ms 100s
34
Skin
Temperature (C)
33
32
31
30
29
28 Wooden Surface
27
26
2-3s
25
1ms 10ms 100ms 1s 10s 100s
Time (log scale)
Foam Plastic Wood Skin Glass Aluminum
35

36. M arble Ti
Pap er le
Rubb
Salt y er
C la
ite
Bran
Plast
r
G
Po ic
lym k
Wate ers
er
r ass
exi -gl
Pl
Foam Plastic Wood Skin Glass Aluminum
36

37. Touch Release Cooling/Warming
Down Touch period
50ms 200ms 100s
34
Temperature (C)
33
32
31
30 Derivative
29
28
C Absolute C
27
26
25
1ms 10ms 100ms 1s 10s 100s
Time (log scale)
x x >
37

38. x10
Plastic
Wood
Paper
Table Top
38

39. Accuracy
100%
100%
detection accuracy
plastic wood
paper table top 0%
0%
39

40. Pressure
34
Temperature (C)
33
32
Contact Time, 50-200ms
31
30
29
4N
28 2N
27
26
0.5 N
25
1ms 10ms 100ms 1s 10s 100s
Time (log scale) Pressure
C
Derivative
Absolute C
40

41. 3 pressure levels = 96% Accuracy
41

42. 42

43. {Derivative
~166ms 25ms
{
43

44. 44

45. 45

46. strokes hand prints
chording
multi-user pressure
curves
46

47. 47

48. an interactive surface
48

49. an interactive surface...
49

50. Heatwave:
Thermal Imaging for
Surface Interaction
eric.cooper.larson@gmail.com
Eric Larson
ubicomplab.cs.washington.edu
Gabe Cohn, Sidhant Gupta
Xiaofeng Ren, Dieter Fox, Beverly Harrison *Ryder Ziola
Shwetak Patel
UbiComp Lab
Design Use Build Laboratory of Ubiquitous Computing
University of Washington University of Washington Intel Research
50

51. 51

52. thermal
input image
Otsu
spatial smoothing video segmentation
(median filter) buffer
hand segmentation
(Otsu thresholding)
temperature trajectory
feature hand trajectory finger tip
calculation search analysis
temporal
derivative
No surface Yes
calibrated?
background
subtraction
bayesian classify pressure
not heat trace -
inference (trees classifier)
is heat trace -
-high pressure
-medium pressure
detect lines -low pressure
save heat traces -hand
(Hough transform)
-not heat trace
detected heat trails
user interface engine
detected lines
52

53. Categorization with Temperature Distribution of the Human Hand Surface
Hideyuki Kokubo, Mikio Yamamoto, Masahiko Hirasawa and Junko Taniguchi
53

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55. Figure 15 Thermal reflections of a person from a wooden wall.
left: visual image; right: close up view with LW IR camera.
Figure 16. Suppression of thermal reflections from varnished) wood as observed through an IR
polarizer oriented perpendicular or parallel to the plane of incidence.
InfraMation 2004, Proceedings Volume 5, 287-298 (2004) 9
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'B&! "<! +8$&H'8,)0! T#6&+! ,)! ,O6&$M#'8,)6! ,K! 'B&! K8)G&$D$8)'E! 'B&! ##
6F$K#H&!$,FGB)&66!,K!'B&!K8)G&$D#+!P,FI+!O&!&CD&H'&+!',!&CB8O8'!#!
Figure 15 Thermal reflections of,K! 'B&! 6D#H8)G!from a wooden wall. #
D&$8,+8H! D$,K8I&0! ! (&#6F$&%&)'6! a person D#$#%&'&$E! !"" $ % & '!
4*%678)E! 8)+8H#'&+! 'B#'! 'B&! %&#)! 6D#H8)G! ,K! 'B&! $8+G&6! 86! )*+,"-./ !
left: visual image; right: close up view with LW IR camera.
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Figure 16. Suppression of thermal reflections from varnished) wood as observed through an IR
P,%&)!8)!678)!'B8H7)&66!V12W!,$!B#$+)&66!V1.W0!
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polarizer oriented perpendicular or parallel to the !""
plane of incidence. %
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&
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*&M&$#I! D#$#%&'&$6! )&&+! ',! O&! H#IHFI#'&+! O&K,$&! D&$K,$%8)G! 'B&! &
68%FI#'8,)! F68)G! 'B&! 'B&$%#I! %,+&I0! QB&! 'B&$%#I! H,)'#H'! &
$&686'#)H&! F6&+! 8)! 'B86! 68%FI#'8,)! P#6! &6'8%#'&+! F68)G! 'B&! %&#)! &
InfraMation 2004, Proceedings Volume 5, 287-298 (2004) 9 58

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