How to get accurate stable data

[liuyi.ntu]

Currently I am using Java SDK to get the real-time data, and my application is to control a keyboard. But the problem is that if I use gazeData.rawCoordinates, the data point on the screen would be very very very unstable and always jumping around. If I use gazeData.smoothedCoordinates, the data become much more stable but time delay occurs. Since my application is on real-time interaction, which is sensitive to the time delay. Is there any method can solve this problem? or is it accuracy problem of the device? Thanks.

[Martin]

The raw unfiltered data does contain noise, this is effectively reduced with our processing filter but as you've notice it introduces a bit of lag. It becomes a trade-off between making the UI more noise tolerant (e.g. larger elements) or accepting the processing delay. You could of course implement your own smoothing filter to have complete control of the parameters but it is a lot of work (more than a simple moving-window average)

Running 60 FPS makes interaction a lot "snappier" but I guess you already have tested this?

[liuyi.ntu]

The raw unfiltered data does contain noise, this is effectively reduced with our processing filter but as you've notice it introduces a bit of lag. It becomes a trade-off between making the UI more noise tolerant (e.g. larger elements) or accepting the processing delay. You could of course implement your own smoothing filter to have complete control of the parameters but it is a lot of work (more than a simple moving-window average)

Running 60 FPS makes interaction a lot "snappier" but I guess you already have tested this?

Yeah, the framerate I am using is 60FPS, which is really faster. But the problem is what I mentioned above, using smoothed data, a little bit lag.

[Anders]

Yeah, the framerate I am using is 60FPS, which is really faster. But the problem is what I mentioned above, using smoothed data, a little bit lag.

If you are dissatisfied of the level of smoothing in GazeData.smoothedCoordinates, then instead, you can do 'your own' smoothing by e.g. using the average of the last 3 raw frames. Do this by maintaining a List of the last 3 GazeData.rawCoordinates and then calculate the average.

[varunk28.2007]

Where exactly are you calculating the smoothedCoordinates or it is directly given by the device. I am not quite satisfied with the smoothedCoordinates and was hoping to use some ML algorithms on the rawCoordinates to compute smoothedCoordinates. I'm aware that it might create some lag but I can figure out how much lag is acceptable.

And how exactly are you calculating the smootherCoordinates ? Is it average of previous coordinate and current coordinate ?

Thanks,
Varun

[Anders]

Where exactly are you calculating the smoothedCoordinates or it is directly given by the device. I am not quite satisfied with the smoothedCoordinates and was hoping to use some ML algorithms on the rawCoordinates to compute smoothedCoordinates. I'm aware that it might create some lag but I can figure out how much lag is acceptable.

And how exactly are you calculating the smootherCoordinates ? Is it average of previous coordinate and current coordinate ?

The smoothed data stream is the average of X past frames.

If you are unsatisfied with the result, you can do your own smoothing based on the raw frames.

[varunk28.2007]

Thanks Anders,

Does the sdk provides cursor control libraries or I have to externally add them ? If it does where to find them.

[Anders]

All the SDKs are generic of nature and do not contain features specific to a OS. Therefore, if you want to control mouse cursor under some version of windows, you need to handle that in your own program.