Selecting a Camera
EFS Blink Tracker will work with most webcams out of the box. However, a camera capable to capture at 30 frames per seconds is recommended. Blinks are very quick events, typically lasting only 100 to 150 milliseconds. At 30fps the camera takes one picture every 33 milliseconds. Maintaining higher frame rates ensures that multiple frames capture the start, middle, and end of the blink, enabling more precise detection and analysis. Below 15 fps blink detection becomes unreliable.
Adjusting Detection Sensitivity
A real-time histogram representing the opening and closing of your eyes is drawn next to the video preview. Blinks are represented by rapid spikes.
- Move the slider on the right to adjust the detection sensitivity.
- The yellow bar represents the threshold at which point a transition between open and closed of the eyes will be recognized as a blink.
- The counter in the top left let's you know if your blinks are properly recognized. Frequently blink while adjusting the slider.
Afterwards move your head around without blinking to test if the settings are too sensitive, in which case rapid movement could produce false positives.
Good Lighting
In low lighting conditions most webcams will compensate by increasing exposure time. This will reduce the frame rate at which the camera records. For best results make sure that your workplace is well lit. If the lighting isn't good enough for your camera, it probably isn't good for your eyes either.
Camera Position
For best results make sure that your face is recorded in a frontal position. The camera can be placed centered on top of your monitor slightly tilted down to your face.
With a secondary monitor, place the camera on the primary monitor about 3/4 towards the secondary monitor. Slightly angle the camera towards your seat.
Troubleshooting and Known Limitations
The most common error to encounter is the camera being blocked by another application. Under Windows only one application can use a specific camera device at a time. Closing the other application will release the camera. If you frequently use your camera for video conferencing, consider getting a secondary camera. EFS Blink Tracker supports switching between multiple camera devices.
When wearing glasses ensure that your pupils are visible and your eyelids aren't covered by the frame. Increase the detection sensitivity as needed. Reflections on the glasses might interfere with the blink detection. Use indirect lighting for better results. Slightly tinted glasses like blue light filters are supported, but more opaque glasses like sunglasses are not.
When games are run in Direct X's exclusive fullscreen mode, other applications cannot draw to the screen. This is mostly an issue with older games and most modern games run in windowed mode natively or support it as an option. Select "Windowed Fullscreen" in your games' video settings; otherwise, only audio warnings will be available for the blink reminder.