Comparison of two eye tracking devices used on printed images
-
Upload
hayes-nguyen -
Category
Documents
-
view
20 -
download
0
description
Transcript of Comparison of two eye tracking devices used on printed images
Comparison of two eye tracking devices used on printed images
Barbora Komínková
The Norwegian Color Research LaboratoryFaculty of Computer Science and Media Technology
Gjøvik University College, Gjøvik, Norway
University of Pardubice, Czech Republic
[email protected], http://www.colorlab.no,
Gjøvik University College, 7.6.2007 ,
2
Introduction Aim Experiment
Media Images Description
Experimental results Discussion and results What the next?
Content of presentation
3
Introduction
Eye tracking technologies are using in extensive area: usability studies color imaging (image difference) reading studies development of internet pages, etc.
To do this kind of studies we need the eye tracker to be precise.
Two eye tracking camera have been disposable (Remote eye tracking device and Head-mounted eye tracking device).
It was not found that the head mounted eye tracking device was used in printed images.
4
Aim
Compare two eye tracking devices used on printed images
Head-mounted Eye Tracking Device (HED) and Remote Eye Tracking Device (RED).
1. Is possibility to use the HED on printed images as RED? 2. How to register a data from the HED to the real world
coordinates. 3. Find out precisions in the different directions of both devices.
(precision in different places, precision in the time aspect, precision on the edges of the image, then stability of the
calibration and etc.) 4. Investigate advantages and disadvantages of both devices.
5
Experimental setup - Media
Head-mounted eye tracking device (HED)
Remote eye tracking device (RED)
8
Two parts of the experiment Experiment with the remote eye tracking device Experiment with the head-mounted eye tracking device.
Number of observers – 20 observers cca 40 data sets from all observers
Determination of a dominant eye Instruction – before and during the experiment Calibration Experiment Questionnaire
Experiment - description
9
Remote eye tracking device Recording of the eye movement – data file coordinates of the point of
regard (gaze data) BeGaze software Matlab program, Excel program
Head-mounted eye tracking device Recording of the eye movement – video (MPEG-2) Converting of the video Stabilization of the video – Simulink model Findings real-world coordinates Matlab program
Analysis
10
0
10
20
30
40
50
60
70
80
90
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
number of cross
dis
tan
ce
[p
x]
0
10
20
30
40
50
60
70
80
90
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
number of cross
dis
tan
ce [
px]
0
10
20
30
40
50
60
70
80
90
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
number of crossd
ista
nce
[p
x]
Distance of points from centre of cross – image A in 1., 3., 5. sequence
Blue = Mean Yellow = Median Green = Max Red = Min
1.
3.
5.
precision in different places
precision in the time aspect
Experimental - results
Image A
Results for the RED:
11
Point coordinates of 5 cross 19 observer
0
40
80
120
160
200
240
60 80 100 120 140 160 180 200 220
x
y
points
mean
median
centre of cross
Point coordinates of 2 cross 15 observer
0
40
80
120
160
200
240
0 40 80 120 160 200 240x
y points
median
mean
centre of cross
Ratio of points inside view angle
010
2030
405060
7080
90100
0,5 1 1,5 2 2,5 3
view angel [degrees]
rati
o o
f p
oin
ts [
%]
Cross1
Cross2
Cross3
Cross4
Cross5
Technical detail according to iView X System:
Gaze Position Accuracy0.5 - 1 deg.
Image B
Experimental - results
12
MEAN MEDIAN MAX MIN
31,1962 29,0273 159,6300 0,6007
Distance of points from centre of cross
0
20
40
60
80
100
120
1 2 3 4 5 6 7 8 9
number of cross
dis
tan
ce
[px]
Mean
Median
Max
Min
Image C
Image B
Experimental - results
13
The head-mounted eye tracking device is not evaluated at this time
The evaluation is in-process Problems at this time:
time-consuming stabilization
Experimental - results
Results for the HED:
14
If real-world coordinates are fixated, I will say that HED can be more precise at least on the same level as RED
HED allows the subject to move more freely, which I considered an important issue.
But from the questionnaire: Most of the observers felt more comfortable with RED, because:
HED - too big/small, observer has to wear it, does not feel freely, etc. The rest of observer:
HED – possibility move by head, HED is part of the observer, position was better for look at the picture, focus and concentration was better
Discussion and results
15
Continue with evaluation of the remote eye tracking device Complete analysis and evaluation of the head-mounted eye
tracking device Statistical evaluation of both eye tracking devices Investigate advantages and disadvantages of both eye
tracking devices
What the next?