Detecting Eyes Closed States Reliably

[Benjamin]

I was browsing through the SDK for my Tobii 4C for .NET and Unity, and did not see any apparent way to detect states when the user’s eye’s are closed.

Two things I’d like to detect:

1. The user blinks while tracking gaze
2. The user is present, but their eyes are closed, and when they open their eyes

Thanks in advance!

[Grant [Tobii]]

Hi @innerscript and thanks for your query. With regard to blink detection, I am afraid this is not something that is implemented as a ready to use algorithm within the Tobii Core SDK. To detect blinks, you would need to set up your own customised counter based upon the typical human blink duration of approximately 300ms.

For detecting the presence of a user, you have already the ‘userpresence’ state which you can implement according to the documentation as described @ https://tobii.github.io/CoreSDK/articles/states.html

Additionally, you can download our Core SDK sample programs demonstrating the use of this state @ https://github.com/Tobii/CoreSDK and navigate to the ‘Interaction States’ directory.

Accordingly, if you are tracking gaze upon an object, with the userpresence state as a conditional expectation, you can count the duration that no gaze data is found until reaching a pre-determined blink threshold. This should similarly allow you to detect the presence of a user when eyes are closed and of course when the eyes open once.

Apologies that you need to create some of this functionality yourself, but hopefully the above links will prove useful for your needs. In any event, please don’t hesitate to let us know if we can provide any further assistance.

[Benjamin]

@Grant [Tobii]

Thank you for the explanation. I’m comfortable rolling my own, and will likely do something similar to what you suggest.

If userpresense state is reliable, and doesn’t require gaze data or eyes visible in the camera to be valid, then detecting blinks and eyes closed states should be OK mapping fall offs in gaze data.

.:: Benjamin

[Grant [Tobii]]

H @innerscript, great! Please let us know how you get on and if you would care to share your code thereafter in the projects section of the forum @
https://developer.tobii.com/community/forums/forum/community-projects/ that would be most appreciated!

[Author]

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