IT UNIVERSITY OF COPENHAGEN

MAGIC pointing for eyewear computers

Shahram Jalaliniya

Diako Mardanbegi

Thomas Pederson

IT UNIVERSITY OF COPENHAGEN

Why gaze-based interaction on eyewear computers?

• Need for touch-less interaction- Interaction on the move- In parallel with real world tasks

• Head & Eye movements as input modalities

• Eyewear device as a platform for gaze-tracker

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Challenge of gaze tracking on eyewear computers

Small size of the head-mounted displays & need for more accurate gaze trackers

Eye FOV: 95°

HMD HMD FOV: 14°

(Google Glass)Big screens

HMD

Accuracy of gaze tracker

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Target acquisition on GUI

• Point & select• Eye-pointing is fast but:

- Works for only big targets

• Head-pointing is accurate but:- Tiring specially for long distances

+

Target size

Distance fro

m

start p

oint

+

Accuracy of gaze tracking

*

Initial point

Target

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Magic (Manual & gaze input cascaded) pointing

• Use gaze as an implicit data to move cursor as close as possible to the target (Zhai,99)

- Liberal approach (fixed distance)- Conservative approach (involve user)

+

+*

Gaze moves the cursor

Close to the target

Manual part of the pointing (Head movement)

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Previous Work

Dimensions

Manual part of pointing

Display setup Strategy

MAGIC pointing (Zhai, S., Morimoto, C.,1999)

Mouse Stationary Liberal/Conservative

MAGIC-Touch System (Drewes, H., and Schmidt, A., 2009)

Touch-sensitive mouse

Stationary Liberal

Look & Touch (Stellmach, S., and Dachselt, R.,2012)

Mouse Stationary Conservative

Head assisted gaze pointing(Spakov & et al., 2014)

Head movements Stationary Liberal

Our study Head movements Head-mounted display

Liberal

Previous work

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Experiment goal

• Investigating utility of MAGIC pointing for eyewear computers (combination of eye & head movements)

• Comparing user performance in a target acquisition task using:

•Head pointing

•Combination of eye & head (MAGIC) pointing

•Eye pointing

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Head pointing

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Magic pointing

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Experiment Setup

• Participants- 16 participants (mean age=29, 2 females)- all highly skilled computer users (x ̅= 4.62, σ= 0.5)

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Apparatus• Head tracker of Google Glass (9DoF)• Home-made monocular wearable gaze tracker (GlassGaze)

with accuracy of 1 degree (about 50 pixel on Google Glass)

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Design (2 x 2 x 2)

• Two pointing modalities: - MAGIC & Head pointing

• Two target sizes- Small (30 pixels ≈ 0.6°) & Big (70 pixels 1.4°)

• Two distances- Near (100 pixels ≈ 2°) & Far (280 pixels ≈ 5.6°)

• 15 repetitions- Median of 15 trials is taken

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Experiment results: Task completion Time

• Head pointing is faster for the short distance

• MAGIC pointing is faster in longer distance

• Target size effect is observed

• No distance effect is observed in MAGIC pointing for big targets

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Experiment results: Error rate (wrong tap)

MAGIC pointing is more accurate for pointing to small

and far targets

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Conclusions

• MAGIC pointing makes it possible to select targets smaller than accuracy of the gaze tracker on head-mounted displays

• MAGIC pointing is faster than Head pointing just for long distances

• In MAGIC pointing the distance does not affect the performance for big targets since in this case MAGIC pointing is similar to eye pointing

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Outlook

• Investigating different strategies for positioning the cursor to the initial point of the manual part in MAGIC pointing

- Fixed minimum distance- Fixed time

• Investigating MAGIC pointing for UI development

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