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

b.kominkova@seznam.cz, http://www.colorlab.no,

Gjøvik University College, 7.6.2007 ,

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Introduction Aim Experiment

Media Images Description

Experimental results Discussion and results What the next?

Content of presentation

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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.

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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.

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Experimental setup - Media

Head-mounted eye tracking device (HED)

Remote eye tracking device (RED)

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iView X System

Experimental setup - Media

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Experimental setup - Images

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Sequence: A B A C A D

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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

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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

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Distance of points from centre of cross – image A in 1., 3., 5. sequence

Blue = Mean Yellow = Median Green = Max Red = Min

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precision in different places

precision in the time aspect

Experimental - results

Image A

Results for the RED:

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Point coordinates of 5 cross 19 observer

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Point coordinates of 2 cross 15 observer

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Technical detail according to iView X System:

Gaze Position Accuracy0.5 - 1 deg.

Image B

Experimental - results

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MEAN MEDIAN MAX MIN

31,1962 29,0273 159,6300 0,6007

Distance of points from centre of cross

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Experimental - results

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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:

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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

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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?

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THANK YOU FOR YOUR ATTENTION