TRACKPixx Demo 9 – Calibrating the TRACKPixx3 and TRACKPixx /Mini

Note

This demo requires TRACKPixx Revision 16 or later. You can check for recent firmware updates at vpixx.com/whatsnew

This demo calibrates the current eye tracking session and displays the calibration results with the gaze follower described in Demo #21. This calibration script works with all VPixx eye tracking solutions, and takes arguments to specify which product is being used (TRACKPixx3 or TRACKPixx Mini), and whether tracking is remote (head-free, available for TRACKPixx Mini only) or uses a chinrest (head-fixed).

For quick calibration in MATLAB, you can call the shell scripts included in DatapixxDemos.zip that implement TPxCalibrationTesting with the correct arguments. The script for each product is listed in the chart below:

Product	Calibration command
TRACKPixx3	TPxTrackpixx3CalibrationTesting
TRACKPixx Mini	TPxTrackpixxMiniCalibrationTesting
TRACKPixx Mini with chinrest	TPxTrackpixxMiniWithChinrestCalibrationTesting

The steps to calibrating the TRACKPixx are as follows:

1- Initialize the USB I/O Hub (TRACKPixx Mini only) 2- Initialize the tracker 3- Display the eye picture for camera positioning and lens adjustment (TRACKPixx3 only) 4- Display the calibration targets one after the other, gather eye data, finalize the calibration and display the calibration results 5- Launch the gaze following demo to verify that the calibration worked correctly

Once this demo is completed, if you call the data recording schedule, the eye data will be calibrated. The TRACKPixx3 will remain calibrated as long as you do not call Datapixx('ClearCalibration'). For the TRACKPixx Mini, a remote calibration will remain active as long as the tracker is not disconnected; a chinrest calibration will persist in MATLAB as long as you do not call clear all; close all;.

The full TPxCalibrationTesting.m file is not included here because it is too large. Please find it your local VPixx Software Tools installation.