08-03-2011, 09:55 AM
presented by:
KARTHIK
K.PAVANKUMAR
S.RAVITEJA
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Introduction:
1. Definition
Active camouflage differs from conventional means of concealment in two important ways: firstly, it makes the camouflaged object appear not merely similar to its surroundings, but effectively invisible through the use of mimicry; secondly, active camouflage changes the appearance of the object as changes occur in the background. Ideally, active camouflage mimics nearby objects as well as objects as distant as the horizon.
2.optical camouflage
Wearable version of illusory transparency made from a tiling of flat panel displays supplied with images from cameras, and a computer processing system. This functioning prototype is limited by the number of sensors and transducers.
Outside of fiction, the concept exists only in theory and in proof-of-concept prototypes, although many experts consider it technically feasible. In 2003, three professors at University of Tokyo — Susumu Tachi, Masahiko Inami and Naoki Kawakami — created a prototypical camouflage system in which a video camera takes a shot of the background and displays it on a cloth using an external projector. The same year Time magazine named it the coolest invention of 2003. With flexible electronics such as a flexible liquid crystal display that would permit display of the background image by the material itself, this form of optical camouflage may closely resemble its fictional counterparts
Phased array optics (PAO) provides a more ideal implementation of optical camouflage. Instead of producing a two dimensional image of background scenery on an object, PAO would use computational holography to produces a three dimensional hologram of background scenery on an object to be concealed. Unlike a two dimensional image, the holographic image would appear to be the actual scenery behind the object independent of viewer distance or view angle
3.Fictional examples
Optical camouflage is a kind of active camouflage which completely envelopes the wearer. It displays an image of the scene on the side opposite the viewer on it, so that the viewer can "see through" the wearer, rendering the wearer invisible. The idea appears in many fictional works, such as the William Gibson novel Neuromancer, where it is referred to as a "mimetic polycarbon suit," and the 1979 novel Mirror Friend, Mirror Foe by George Takei and Robert Asprin. Also referred to as "thermoptic camouflage" or simply "thermoptics," this technology was popularized by the sci-fi manga (and later anime) Ghost in the Shell and Gantz..
In fiction
The active camouflage suit by name is credited to science fiction author Philip K. Dick in his 1974 novel A Scanner Darkly. Worn by the narcotics double agent Bob Arctor/Fred, the "scramble suit" is described as a flexible sheath covering the body of the wearer with a reflective/refractive coating on the inside surface that transfers the camouflaging pattern — projected by a holographic lens mounted on the wearer's head — onto the outside surface of the sheath.
Dick's invention has been copied many times in novels, films and video games to become a standard device in science fiction. Examples appear in the Arnold Schwarzenegger film Predator, the James Bond film Die Another Day, the Metal Gear Solid video game series, the MMOFPS game PlanetSide, the,halo video game