What does water look like?

Abstract

What makes images of water look like water? We conducted four psychophysical experiments to isolate perceptual qualities that make water easy to recognize. Water recognition is facilitated by colour and by three patterns of waves. Low spatial frequencies (LSF) (<4.4 cpd) contribute more to recognition than high spatial frequencies (HSF). Here we describe the experimental methodology and results. Knowing which aspects of appearance identify water can inform perceptually inspired depiction of water, can create visual illusions and can reduce computation in realistic simulations.