EyeLink II Scene Camera User Manual
©
2004-2007 SR Research Ltd.
1
1. Introduction
The standard EyeLink II setup allows users to record eye movements at a fixed
viewing distance (e.g., computer monitor, TV, projected screen, etc). The
EyeLink scene camera option provides a powerful extension so that
participants’ gaze position can be tracked on a real world scene video being
captured from a head mounted scene camera. With horizontal disparity
information from binocular recording capability of the EyeLink tracker, the
scene camera option provides a build-in parallax error correction, which
permits accurate gaze overlay regardless of viewing depth relative to calibration
plane.
In a scene camera experiment, either a color or high resolution black and white
scene camera is used to generate 30 Frames (60 fields) of scene video recording
per second. The scene video is streamed to an external video overlay box,
which can be used to superimpose real-time overlay graphics (current gaze
position, time stamp, etc.) generated by the EyeLink II tracker on the video
source. The composite output can then be displayed on a TV monitor and
recorded by a VCR or DVD recorder. Alternatively, the SR Research SceneLink
application can be used to save the scene camera video as digital video (in .AVI
file format) without any gaze overlay graphics. A binary millisecond time code is
written to every scene camera field to allow for excellent synchronization
between the EyeLink gaze data and scene video. The SceneLink application is
used to merge these two sources of data to create overlay graphics during
playback.
This manual is for use with the EyeLink scene camera option together with the
SceneLink application. Please send all bug reports and comments to SR
Research Ltd (
).
