Gaze Point Coordinate System

[Hirnmoder]

Hello,
thank you for sharing the STG+ dataset. Currently I'm working on a similar gaze estimation task and therefore would like to use your dataset for training.

My question relates to the gaze_point entries in the (train|val)_meta.csv. They link to serialized numpy arrays and I'm able to load them as expected. But I have no clue what these values mean.

• The values are two dimensional (xy or yaw,pitch or ...)
• The values range from 3.11 to 56.66 on the first dimension and from 0.16 to 33.46 in the second dimension

Please help me clarify what these values are:

• Are they coordinates on the screen in pixels (seems unlikely because of the value range)?
• Are they coordinates on the screen in centimeters?
• Are they angles in degrees (seems also unlikely because no negative values exist)?
• In which coordinate system are they (camera, screen)?
• Is there any possibility to calculate gaze angles from these values? (maybe using extrinsic camera parameters provided by this repository?)

Thanks in advance! :)