iTrace vs PyGaze

iTrace is a free, MIT-licensed toolkit for analyzing webcam eye-tracking data, with a scientific core built on NumPy and SciPy. It computes gaze in degrees of visual angle and detects fixations, saccades, and microsaccades using I-VT, I-DT, and Engbert–Kliegl methods. Pupil tools include blink detection and interpolation, preprocessing, and eye-crop segmentation measured in pixels or relative to iris size. Affine screen-space calibration reports calibration error and gaze-quality measures. The command-line tool analyzes gaze CSV files and exports JSON reports. Optional webcam capture uses OpenCV and MediaPipe, and optional interfaces include a local HTML app using FastAPI and WebSockets and a Streamlit dashboard. Live workflows can export derived gaze, pupil, and capture CSVs. By default, the workflow does not save raw eye video or persisted eye-crop images, though live viewing may send a temporary JPEG crop to a browser over a local WebSocket. The project says its checks use synthetic ground truth rather than real eye-tracking data or a reference device. Webcam pupil size is a relative proxy, not a measurement in millimetres.

PyGaze is an open-source Python toolbox for running eye-tracking experiments. It provides a shared interface for stimulus presentation and tracker communication, with support for EyeLink, SMI, Tobii, and mouse-simulated tracking. For stimuli, it works with PsychoPy and PyGame. The EyeTracker interface covers calibration, recording, gaze sampling, pupil-size retrieval, and fixation and saccade event functions. Gaze-contingent tools include forced retinal location, a cursor that follows gaze, and areas of interest. PyGaze is free at free and supports Linux, macOS, and Windows. Downloads include pip installation instructions for those systems, source packages, and portable Windows environments. The about page recommends Python 2.X and describes its audience as people with minor to advanced programming skills. Some tracker connections require separate steps: PyLink is proprietary and requires registration with SR Research, while SMI and Tobii API downloads must be requested from their makers. PyGaze supplies fresh gaze samples at the tracker’s sampling rate and returns the newest available sample between fresh samples.