Literature Review, Chow Zi Jie (11)

Anderson, Johnston, McOwan. (n.d). Motion Illusions and Active Camouflage. Retrieved from: http://www.ucl.ac.uk/~ucbplrd/motion/index_motion.html

Anderson, Johnston, McOwan described camouflage on a basis of living organisms. They mentioned that Colt (1940) wrote a paper on animal camouflage and identified several methods of camouflage used by those organisms, among them disruptive, cryptic, mimicry and countershading. They further mentioned that Ender (1986) defined five stages of predation by predatory animals: detection, identification, approach, subjugation, and consumption. This in military terms is roughly similar, where the soldier has to detect, identify, get in-range and eliminate their enemy. They stated that there are two main aspects of camouflage, cryptic and disruptive. 
Cryptic camouflage renders bearers difficult to detect by imitating the immediate visual background, where the colouring, size and distribution of pattern elements must be in aspects pertinent to the visual system of the observer. Disruptive patterns merge well with the background, along with some parts of the periphery and thus are inconspicuous, as other areas will contrast highly and draw the observers attention to less essential areas of the bearer’s form.
Anderson et.al. also described the computational visual processing of the mammalian visual system, in detecting camouflage. This, in particular has relation to the human visual system, similar to how a human’s visual system works, therefore, can be used to study how camouflage is detected. Anderson et.al. suggest that a single layer of photosensitive receptor cells line the retina so the visual field can be treated as a two-dimensional map of receptor activations. They state that many artificial models of the visual system simplify situations, ignoring complex colour channels and consider only light intensity. They stress that the information at the lowest level of these simulations of the visual processing pathway is an array of brightness values. The visual system is hierarchical, with each level performing simple computations from the output passed to it from lower levels. It is also combinatorial, as separate information channels are combined in varying ways to reveal features in the visual field.

References:
Anderson, Johnston, McOwan. (n.d). Motion Illusions and Active Camouflage. Retrieved from: http://www.ucl.ac.uk/~ucbplrd/motion/index_motion.html