Disruptive Camouflage and Psychophysics

In order to process information efficiently and quickly visual systems take short cuts that exploit redundancies and regularities in natural scenes. Camouflage exploits these shortcuts in order to conceal the location or identity of objects. Identifying and isolating the perceptual processes exploited by camouflage can help us understand both how the visual system works and how to make camouflage more effective.

Psychophysics is methodology used to study perception. It uses objective measurements of the point where a stimulus feature can just be detected or where two stimuli can just be discriminated. We use this methodology to investigate how disruptive camouflage works and what influences its effectiveness.Disruptive colouration is a visual camouflage which comprises false edges and boundaries. It features contrasting areas of pigmentation across the animal’s surface. An often ignored feature of disruptive camouflage is high contrast edge ‘enhancement’ of the coloured patches – light patches have lighter edges and dark patches have darker edges.

In this talk I will use objective measurements to demonstrate that 1) edge enhancement improves crypsis beyond simple background matching, potentially by increasing pictorial depth; 2) edge enhancement disrupts shape discrimination and 3) edge enhancement can help to conceal a target’s identity even when it is not hidden.