Image-based scanpath comparison with slit-scan visualization

The comparison of scanpaths between multiple participants is an important analysis task in eye tracking research. Established methods typically inspect recorded gaze sequences based on geometrical trajectory properties or strings derived from annotated areas of interest (AOIs). We propose a new approach based on image similarities of gaze-guided slit-scans: For each time step, a vertical slice is extracted from the stimulus at the gaze position. Placing the slices next to each other over time creates a compact representation of a scanpath in the context of the stimulus. These visual representations can be compared based on their image similarity, providing a new measure for scanpath comparison without the need for annotation. We demonstrate how comparative slit-scan visualization can be integrated into a visual analytics approach to support the interpretation of scanpath similarities in general.