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Tagged: Accuracy noise calibration
- This topic has 3 replies, 2 voices, and was last updated 4 years, 9 months ago by Grant [Tobii].
- 20/08/2018 at 07:58 #8736Theodor BozinisParticipant
Hello, I am currently developing an application that uses the eye tracker to collect data of people reading text or seeing a photo. My issue is that although there are occasions that both the precision and accuracy are good enough (but not perfect), all the other times I can see an error of at least 100 (on a 24″ 1080p screen) and a lot of noise. In all of the bad instances I can predict that there will be a lot of noise right after the first dot explodes on the calibration. I can see that the first one is taking way more time to explode than the rest of them. So, do you have an alternative calibration with more points (assuming that this can help)? I don’t mind the extra time spent to a better calibration. Can I achieve better results somehow? (I already tried dark and good positioning)20/08/2018 at 10:20 #8739Grant [Tobii]Keymaster
Hi @tbozinis. Thanks for your query. If you feel the regular calibration after setup is inadequate, you can run the 9-point calibration to improve eye tracking accuracy and performance. If you click on the Tobii Core Software in the System Tray Icon, then click on your name at the bottom right (just next to the moving eyes), you should see an option to “test and improve calibration”
This will demonstrate to you graphically the accuracy across the 9 points of your screen. You can also choose to improve calibration here by clicking on that option on the screen.
In addition to recalibrating it is also useful to consider improving environmental conditions such as: ensuring no strong sources of infrared light (open windows, strong spotlights) are present near the eye tracker, the user is not wearing heavy makeup or facial piercings and that the user is positioned at an optimal distance of around 30cm between tracker and eyes.
Please go through these and let us know how you get on. Thanks.02/09/2018 at 17:45 #8774Theodor BozinisParticipant
Hey Grant, I tried a 9-point calibration using the Tobii dynavox (I couldn’t find any example code on how to launch a 9p calibration). So, my first question is if there is a way to choose manually (in code) where will the calibration points will be. And secondly, where can I find some example code for at least a 9p calibration? Also, I would love to use the “stock” animation for the calibration (that on with the exploding blue dots from the tobii core app), can I still use it with the 9p (or more) calibration?
P.S. I had already did all the environmental tricks…03/09/2018 at 15:11 #8776Grant [Tobii]Keymaster
Hi @tbozinis, could you kindly clarify your hardware setup as Dynavox is not typically supported on this forum which is generally dedicated to the Tobii Tech range of eye trackers.
However, in terms of running custom calibration setups, a couple of options are possible depending on your hardware and licence agreement:
If you have the appropriate analysis licence, you can use the Tobii Pro SDK which does indeed support placing calibration points and predetermined parts of the screen.
Also the Tobii Core SDK Stream Engine API supports custom calibration but this requires the purchase of a special licence (and justification) for doing so and will only work with select eye tracker models.
Certainly, from a non-SDK perspective, I am afraid there is no software we produce that will allow you to run this kind of customised calibration setup directly.
I will ask on your behalf if we can release the stock animation we use, but of course this would only be of use in a development (SDK) environment.
If you could also indicate which SDK you are using or intend to use, that would be most helpful.
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