Unit of Pupil Size and Raw Coordinate

[Syamsul]

Dear Martin

I need some values of the pupil size and pupil coordinates that I will input it to some formula, but right now i am still difficult to know about it's unit. Could you give me some description about unit of the "Gazedata.leftEye.pupilSize" and "Gazedata.leftEye.rawCoordinates.x", are pixel or mm?

thanks
Syams

[Martin]

Hi Syams,

PupilSize is camera sensor pixels (not millimeters).

RawCoordinates.x is screen pixels where 0,0 is top left.

[Syamsul]

Hi Martin, thank you for your respon. Let me ask one more questions, is eye tribe api provide function to get Y and X pupil coordinates in camera (eye tracker) image? and how about camera eye tracker resolution?

Thanks
Syams

[Anders]

Hi Sam

The EyeTribe API do not expose camera sensor resolution nor camera pupil coordinates.

Could you give me some description about unit of the "Gazedata.leftEye.pupilSize" and "Gazedata.leftEye.rawCoordinates.x", are pixel or mm?

The unit of pupil size is camera space pixels and the unit of gaze coordinates are screen space pixels. Pupil coordinates are relative screen space.

What are you trying to achieve?

BR,
Anders

[Syamsul]

Hi Anders

Actually, i try to achieve the value of left and right eyes in world coordinate or The X- and Y-coordinates of the right and left eye pupils in the camera image, as a fraction of the camera image size. Is there any possiblity to achieve these value using the eye tribe api?

Thanks
Syams

[Martin]

Syams,

I think it could be helpful to take a look at the TrackBox component which we have open sourced.

The coordinates for the left/right pupil center is normalized to 0-1 range for X & Y axis.