Adjusting The Camera - LCT Eyegaze Edge User Manual

*if no eye image is present when you are in an Eyegaze screen try pressing control-F12.
The eye image display contains:
a) a display of the full camera image (right window)
b) a magnified display of the eye (left window)
c) a focus indicator (between windows)
Use the display of the full camera image on the right to help center the camera on the user's eye. Until
the eye is clearly visible in the window on the right there will be no image on the left. A close-up image
of the eye will appear in the left window once the camera is adequately focused on the eye. Always use
the full camera image on the right to aid in positioning the system and camera since the close-up image
will always be centered in its window, even when the eye is not actually centered in the camera's field
of view.
The presence of an eye image in the close-up (left) window is an indication the eye is being "tracked."
You will see a bright tracking dot in the center of the pupil and a very tiny dark tracking dot in the center
of the glint spot (corneal reflection). Look for these tracking indicators during the process of positioning
the system. The Eyegaze Edge and its camera are in a relatively good position when the image of the
eye is centered and the tracking indicator dots are present.

1.3.3 Adjusting the Camera

The camera angle and the focus range must be adjusted so a clear close-up image of the user's eye
appears, and the focus indicator is centered over its tick mark. Typically either eye may be used.
Position the Eyegaze screen a comfortable distance from the user, typically around 20-26 inches away
from the screen, with the top of the screen at eye level or lower. The camera can be focused as close
as 16 inches from the user's eyes to as for away as 30 inches, based on user preference. Note: It is
usually easier for the user to move his eyes around the screen when it is not too close.
Focus range indicator
A focus indicator is displayed between the two eye images to assist in fine-tuning the focus. The focus
indicator is a white dot that moves up or down showing whether the subject is too close or too far from
the camera. If the focus indicator is centered on the reference tick mark, the eye is in perfect focus. If
the focus indicator reaches either end of the scale, the eye is approximately 0.75 inch (2 cm) out of
focus. As an additional indicator, the images of the eye turn red or green if the eye is significantly out of
focus. Green indicates that the user should move (go) forward to restore good focus, and red indicates
that he should move backward (retreat).
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