Outline Application areas Stateoftheart technology Eye tracker NCCUCS

Outline 眼動儀類型 應用領域與最新技術 – Application areas – State-of-the-art technology Eye tracker @NCCUCS 1. 0 (wearable) Eye tracker @NCCUCS 2. 0 (remote) Gaze-based HCI Demo (展示) Conclusions

眼動儀類型 侵入式 – 搜尋線圈法（Search Coil ） – 眼電圖法（Electro-Oculography） 非侵入式 – 紅外線視訊（Infra-red Video System） – 光學式瞳位追蹤(Optical-type Eye Tracking Device) – 紅外線眼動圖法（Infra-red Oculography） – Purkinje 影像追蹤法（Dual-Purkinje-image）

基於影像之眼動追蹤 An eye tracker is a device for measuring eye positions and eye movements. The most popular variant uses video images from which the eye position is extracted. Input source: visible spectrum vs. infrared

眼動 Eye Movements Eye movements are typically divided into fixations (凝視when the eye gaze pauses in a certain position) and saccades (掃視 when it moves to another position). The resulting series of fixations and saccades is called a scanpath. (掃描路徑)

Eye. Writer Project

Web Design (U. of Manchester) Heat map Gaze plot

Usability Study: Google Search Evaluation

Gaming

Driving Behavior [Andrew T. Duchowski]

Character Input Eye. Write [Andrew T. Duchowski]

Media Research The Poynter Institute : http: //www. poynter. org Published first eye track study in 1991. More results published in 2000, 2004 and 2007. Eyetrack ’ 07: http: //www. poynter. org/content/conten t_view. asp? id=105035

Text 2. 0

Research Communities ACM SIG/CHI Eye Tracking Research and Applications (ETRA) Symposium: http: //www. e-t-ra. org/ COGAIN: Communication by Gaze Interaction http: //www. cogain. org References: http: //www. cogain. org/downloads/

State-of-the-art Eye tracking Technology Hi-Speed (SMI i. View X™ Hi-Speed) Head-Mounted System Remote tracking Integrated with LCD monitor

Mobile Eye Tracker 1. 0 @ NCCUCS scene camera eye camera

Key Objectives Low-cost (NTD 10, 000 vs. 1, 000) Mobility Easily customized for specific applications On-line processing Sampling rate? Accuracy?

System Architecture Eye image Calibration process Preprocessing 9 pairs of points Pupil detection Calibration Gaze point projection Scene image

Pupil Detection (I): extracting feature points

Pupil Detection (II): Ellipse fitting using RANSAC

Pupil Detection (III): checking fitness measure • Ellipse model: Number of bright vs. dark points inside and out the perimeter

Results

HCI Application: Eye Scrolling

HCI Application: Eye Gaming

HCI Application: Eye Typing

Mobile Eye Tracker 2. 0 @ NCCUCS Improve the pupil detection algorithm to alleviate corneal reflection problem. Enhance the accuracy by compensating for head movement. Construct and test a remote eye tracker. More HCI applications using the remote eye tracker. Use the eye tracking device to assist mobile user interface design.

Improved Pupil Detection

Allowing Head Movement

Remote Eye Tracker

Experimental Results (Wearable) Calibration Original error point Compensate for head movement (error/standard deviation) 1 98. 17 32. 91 (12. 7) 2 137. 54 55. 89 (10. 94) 3 108. 20 29. 69 (9. 57) 4 76. 30 28. 79 (21. 19) 5 113. 30 22. 49 (7. 79) 6 117. 86 34. 83 (10. 96) 7 116. 53 33. 31 (8. 01) 8 112. 56 16. 03 (6. 78) 9 146. 73 26. 49 (9. 66) 1 cm = 38 Pixels

Accuracy (Wearable)

Experimental Results (Remote) Calibration point Original error Compensate for head movement (error/standard deviation) 1 238. 73 39. 69 (24. 6) 2 227. 51 63. 56 (22. 82) 3 132. 97 44. 30 (21. 49) 4 222. 97 51. 66 (30. 94) 5 306. 58 31. 15 (16. 71) 6 280. 79 51. 66 (21. 83) 7 311. 89 69. 03 (41. 57) 8 344. 24 69. 88 (31. 71) 9 347. 03 64. 66 (24. 41)

Accuracy (Remote Eye Tracker)

Demo: Web Browsing

Demo: Photo Viewing

Demo: Interactive Story Telling

Demo: Tic-Tac-Toe

Gaze Path Analysis Recursive intersection – Find the similarity between two scan paths – Order of scanning is irrelevant – Suitable for processing fixation data Modified dynamic time warping – Order of scanning is taken into account – Can handle both fixation and saccade data

Recursive Intersection Path 1 Path 2

Recursive Intersection: Example

Dynamic Time Warping (DTW)

Modified DTW (MDTW) time Y-axis X-axis

MDTW Result

Summary Eye tracking device – Low cost (<$10, 000 NTD) – Head-mounted with mobile functionality – Remote eye tracking – Allow slight head movements – Accuracy: suitable for some HCI applications, image viewing tasks, not high enough for reading HCI applications