Effects of 180 Degree Image Rotation on Eye Movement Pattern

摘要

This study quantitatively compares eye movement (EM) patterns of subjects viewing static pictures for short (5 seconds) period of time. Each image stimulus is viewed in its original appearance and under a linear transformation - rotation by 180 degrees. Eye movements for the original and transformed images are compared in terms of similarity in position of fixations (SP factor) and their sequence (SS factor). The stimuli come from four distinct groups. First group contains "pseudo-natural" images that have typical natural image Fourier power distribution (1/f) and random phase factor. This creates a cloud-like pattern without any particular shape outlines. Second group contains single objects that might appear in the environment in almost any orientation. Such objects do not posses any intrinsic polarity such as "up" and "down" (for example a bundle of keys). The third group contains single object with well-defined polarity (for example a tree). Finally, the fourth category contains scenes with multiple objects and well-defined polarity (for example a picture of a room). We investigate the effects of the transformation for each category on EM pattern and evaluate similarity of viewing strategies for individual subjects.