Eye Calibration in ARCADE for iRec eye tracker

[Raghuram5032]

Hello,

I'm currently working with NHPs using ARCADE software, recording with BlackRock microsystems and iRec eyetracker. I need to do eye calibration. Currently with respect to iRec eyetracker, there is no calibration script present.

I'm planning to manually calculate the offset, gain (from figure 1) and the transformation matrix (from figure 2) manually by designing scripts in arcade as shown in the figures.

Q1: Is it possible to calculate these values in this way and is this the correct way to do this?
Q2: Where in the arcade eyeserver scripts can we apply these values?
Q3: If you have any calibration scripts for iRec, could you please share the codes?

Thank you in advance.

[jsdpag]

In the ARCADE folder, you will find a batch file called:

\ARCADE\arcade\EyeServerCalibrateEyelink.bat

Which, in turn, opens Matlab and runs CalibrateEyelink.m

This sets up a mini ARCADE session to control eye calibration.

Me, I've only used this with the SR Research EyeLink. I guess that you are using iRecServer.exe to communicate with your iRec system. There might be a way to configure CalibrateEyelink.m to use iRecServer.exe. But, if not, it could serve as a template.

[KatharineShapcott]

I've been using iRecHS2 with iRecServer.exe but with another display backend (Unreal Engine). As far as I know you need to enter the calibration point locations into iRec yourself in centimeters to be able to correctly apply a calibration.

So if you use ARCADE to show 5 calibration points at (0,+10), (+10,0), (0,0), (-10,0), (0,-10) in degrees then in iRec you need to enter the distances in centimeters of each point from the subject's eye.

In the iRec interface the first column is the horizontal distance, the second is the vertical distance and the third is the distance in front of the subject. (when displaying the points on a screen at a right angle to your subject the third column is the same value repeated).

There is a useful figure for this from their manual: https://staff.aist.go.jp/k.matsuda/iRecHS2/trial/calibration.pdf

I hope this helps!