Common concepts

In all language bindings, some concepts are the same. This includes which coordinate systems are used, how time stamps are defined and how licenses are handled. In this section we have collected information that is useful no matter which language binding is used.

  • Gaze

    The primary output of any eye tracker is where the person in front of it is looking. However, how this is defined varies between brands. In this section, we define how it should be interpreted in the context of the Pro SDK. Read more...

  • Coordinate systems

    Depending on your application, the requirements for how the gaze point and gaze origin is presented varies. Sometimes the most appropriate presentation is in 3D space while in others 2D is better. Because of this, the Pro SDK utilizes three different coordinate systems. Read more...

  • Pupil diameter

    Another output from eye trackers available through the Pro SDK is the pupil diameter. In order to utilize this to its full potential, it is useful to know how it is defined by the Pro SDK. Read more...

  • Time stamps and timing

    In most applications, the data from the eye tracker needs to be coordinated with something else in order to be useful for analysis at a later stage. This can be when a stimuli was presented on the screen or when a specific event happened in another data source such as EEG or GSR. This is made possible by knowing how to interpret the Pro SDK timestamps and using its synchronization capabilities. Read more...

  • Validity codes

    All gaze related data in the Pro SDK has its own validity codes. A validity code denotes how trustworthy the data received is, but what this means can vary between different kinds of data. Read more...

  • Calibration

    In order to get accurate and precise gaze data, it is very important that the eye tracker adapts the eye model it uses for the person in front of the eye tracker. This is done during the calibration procedure. Read more...