Computer vision, camouflage breaking and countershading

• Published in: Philosophical transactions of the Royal Society of London. Series B. Biological sciences Vol. 364; no. 1516; pp. 529 - 536
• Main Authors: Tankus, Ariel, Yeshurun, Yehezkel
• Format: Journal Article
• Language: English
• Published: London The Royal Society 27.02.2009
• Subjects: Adaptation, Biological - physiology; Animal camouflage; Animals; Apatetic Coloration; Camouflage; Camouflage Breaking; Caterpillars; Color; Colors; Computer Simulation; Computer Vision; Contrast Sensitivity; Convexity; Countershading; Cylinders; Models, Theoretical; Pattern Recognition, Visual; Predators; Thayer's Principle
• ISSN: 0962-8436; 1471-2970; 1471-2970
• DOI: 10.1098/rstb.2008.0211

Camouflage is frequently used in the animal kingdom in order to conceal oneself from visual detection or surveillance. Many camouflage techniques are based on masking the familiar contours and texture of the subject by superposition of multiple edges on top of it. This work presents an operator,
for the detection of three-dimensional smooth convex (or, equivalently, concave) objects. It can be used to detect curved objects on a relatively flat background, regardless of image edges, contours and texture. We show that a typical camouflage found in some animal species seems to be a ‘countermeasure’ taken against detection that might be based on our method. Detection by
is shown to be very robust, from both theoretical considerations and practical examples of real-life images.