Converting coordinates to pixels for Tobii x120

[Aina]

Hello,

I’m currently conducting research on a project that used Tobii X120 eye tracker for eye tracking. I could not identify the metric used for the coordinates in the output but it definitely does not look like it’s in pixels. An example of coordinates:

X: 0.555511
Y: 0.51207

The study was conducted on videos with 1280×720 resolution. I’m trying to convert these coordinates to pixels and one of the topics suggested to multiply it with the current resolution https://developer.tobii.com/community/forums/topic/can-we-get-gaze-information-in-pixels-with-net-tobii-research/

I’m wondering if this is applicable to all data collected from Tobii eye tracker and if not are there other ways to accurately convert these coordinates into pixels?

Could these coordinates be cartesian coordinates? And if so, what could be the scale factor in my case?

[Grant [Tobii]]

Hi @ainaazlin and thanks for your query. The Tobii X120 is part of the Tobii Pro business department.
This forum is intended for support with the Tobii Tech Consumer level eye trackers (4C, Eyex, etc) and their associated SDK’s.

Please get in touch with Tobii Pro Support team directly @ http://www.tobiipro.com/contact/contact-support/ for an
answer to your query. Apologies for the inconvenience and thanks for your understanding.

That being said, It would appear that the coordinates system you reference does indeed refer to the fraction of the screen resolution. Namely (1,1) would correspond to (1280,780), etc, so if you look in the extremities of the screen you should be able to confirm this.

It would also depend on the co-ordinate system you are using with which you have many options in the Tobii Pro SDK and Tobii Pro lab software so you could not necessarily guarantee all tracking setup would be using the system notation.

[Aina]

Thank you so much for your swift reply! I will further enquire with the business department!

[Author]

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