Navigation :

> > > >

Ocumen Filters - Overview

The Ocumen filter library is a collection of algorithms that are designed to process eye tracking data and detect eye tracking events.

By applying filters to Advanced Signals directly or to an Ocumen recording, you can refine the data to make it more useful for analysis, and you can detect events in the data such as fixations and saccades. Doing so gets you closer to understanding user behavior and cognitive processes.

To accommodate a wide variety of use cases, the Ocumen filter library is designed as a low level library which is performant, easy to use and versatile with both C# and Python API surfaces. The filter library runs on Windows and Android.

Filter Usage

To use a filter, a function call is made to the filter library from C# or Python. In the function call, a set of arrays is specified as input. Also, for most filters, a set of filter-specific configuration parameters is specified to customize the filter’s behavior. The filter function then processes the input data, updates the output array and returns a code describing if the processing succeeded or not.

A common workflow with the filter library is to chain filters together to form a filter pipeline, the output of one filter being used as the input of the next filter. See below for examples of filter pipelines.

Included Filters

Ocumen includes the following filters.

Eye tracking filters

Filters that classify eye tracking events or extract additional useful data from gaze data.

Eye tracking processors

Filters that process eye tracking data to make it more useful. These filters are often used to prepare data for eye tracking filters.

Generic processors

Filters that process temporal data and are not limited to eye tracking.

Fixation

Simple C#, Python
Tobii IVT C#, Python
Dispersion Angles C#, Python

Saccade

Simple C#, Python
Non-Fixation C#, Python
Smeets-Hooge C#, Python

Velocity

Instantaneous C#, Python
Windowed (index-based) C#, Python
Windowed (time-based) C#, Python

Pupil

Lam-Thomson-Corbett C#, Python

Spectral

STFT Velocity C#, Python
STFT Velocity Extended C#, Python

Fusion

Transform Binocular Gaze C#, Python

Smoothing/Interpolation

Savitzky-Golay Smoothing C#, Python
Catmull-Rom Resampling C#, Python
Calculate Catmull-Rom Resampling Length C#, Python
Resample Binocular Gaze C#, Python
Resample Position Guide C#, Python
Resample Entrance Pupil C#, Python
Resample Pupil Size C#, Python

Invalidation

Detect Near Blinks C#, Python
Invalidate Near Blink: Binocular Gaze C#, Python
Invalidate Near Blink: Entrance Pupil C#, Python
Invalidate Near Blink: Pupil Size C#, Python
Invalidate Near Blink: Position Guide C#, Python
Invalidate Eyes: Binocular Gaze C#, Python
Invalidate Eyes: Blink State C#, Python
Invalidate Eyes: Entrance Pupil C#, Python
Invalidate Eyes: Pupil Size C#, Python
Invalidate Eyes: Position Guide C#, Python

Noise

Add Noise C#, Python

Temporal

Sort By Time C#, Python
Timeshift C#, Python
Verify Delta Above C#, Python
Verify Delta Below C#, Python

Get Started

To get started using the Ocumen filter library, see the following resources.

Sample

Try some filters in near-real-time in VR in the the following sample:

Ocumen Signals & Filters Sample.

Tutorials

Check the Getting Started tutorials on how to use the filter library:

C#
Python

APIs

Read the API reference pages for detailed information about each filter:

C#
Python