Blink detection

[Riccardo]

Hi all!

Can anyone tell me the dimension of the time window for blink detection?
It would be fantastic to avoid tests 😀

Thank you

[Grant [Tobii]]

Hi @riccardomollo, as mentioned the Tobii Core SDK Does not contain a blink detection algorithm builtin so it is up to the develop what they believe is an appropriate time counter.

Blinks typically last 300-400 milliseconds, so if you base your own detection function around this value it should be sufficient.

Please let us know if we can be of further assistance.

[Pascal Seitz]

Hi, the issue with the current api is, there is no seperation between closed lid and presence of the eye (e.g. when the user moves the head slightly of of range, it counts as blinking).
It would be helpful if the api would provide somehting like TOBII_VALIDITY_INVALID_CLOSED, TOBII_VALIDITY_INVALID_NOT_TRACKING, TOBII_VALIDITY_VALID.

[Grant [Tobii]]

Hi @pascalius, thanks for your suggestion. I wonder if the user presence state is of use to you? Brief description @ https://tobii.github.io/CoreSDK/articles/states.html

This would allow your program to be aware that a user is present regardless of whether eyes are open or not. In any event, I will pass along your idea to the developer for further consideration. If you would care to expand on your intentions, that would be helpful.

[Pascal Seitz]

Hi, thanks for you suggestion. User presence in its current api would help with blinking with both eyes, but not blinking with one eye .. more like winking actually. Blinking with one eye here would be some form of user interaction.

[Grant [Tobii]]

Hi @pascalius, interesting idea although the consumer range of the Tobii eye trackers are designed to work alongside traditional keyboard and mouse rather than a replacement, for which there is the Tobii dynavox range of trackers.

That being said, if you check out the Tobii Core API reference guide with respect to the Eye Position Data class, herein
we describe the methodology for obtain validity codes for each eye

For example, “HasLeftEyePosition” Gets a value indicating the validity of the left eye position.

Declaration

public bool HasLeftEyePosition { get; }

Further details about this method online @ https://tobii.github.io/CoreSDK/api/Tobii.Interaction.EyePositionData.html

Perhaps this is of use to you?

[Yu]

Hello Tobii Support,

We conducted an experiment which measuring eye-movement by Tobii Glasses 3.

However, we want to obtain the data related to the blink rate.

There is “eye movement type” and “gaze event duration” from the exported data.

Can we consider the output data “EyesNotFound” and 100 ms < “Gaze event duration” < 400 ms to be equivalent to blinking?

Thanks,

Yu

[Grant [Tobii]]

Hi @atai and thanks for your query. The Tobii Glasses is part of the Tobii Pro business department.

This forum is intended for support with the Tobii Tech Consumer level eye trackers (ET5, 4C, etc) and their associated SDK’s.

Please get in touch with Tobii Pro Support team directly @ https://connect.tobii.com/ for an
answer to your query.

[Author]

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