14-06-2009, 09:16 AM
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This article is presented by:
SUDEESH S
COMPUTER SCIENCE AND ENGINEERING
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE &TECHNOLOGY,
KOCHI-682022
OPTICAL CAMOUFLAGE
ABSTRACT
While new high-performance, light-transmitting materials such as aerogel and light-transmitting concrete compel us to question the nature of solidity, a new technology developed by University of Tokyo seeks to make matter disappear altogether. Scientists at Tachi Laboratory have developed Optical Camouflage, which utilizes a collection of devices working in concert to render a subject invisible. Although more encumbering and complicated than Harry Potter™s invisibility cloak, this system has essentially the same goal, rendering invisibility by slipping beneath the shining, silvery cloth. Optical Camouflage requires the use of clothing “ in this case, a hooded jacket “ made with a retro-reflective material, which is comprised by thousands of small beads that reflect light precisely according to the angle of incidence. A digital video camera placed behind the person wearing the cloak captures the scene that the individual would otherwise obstruct, and sends data to a computer for processing. A sophisticated program calculates the appropriate distance and viewing angle, and then transmits scene via projector using a combiner, or a half silvered mirror with an optical hole, which allows a witness to perceive a realistic merger of the projected scene with the background “ thus rendering the cloak-wearer invisible.
INTRODUCTION
Invisibility has been on humanity's wish list at least since Amon-Ra, a deity who could disappear and reappear at will, joined the Egyptian pantheon in 2008 BC. With recent advances in optics and computing and with the advent of flexible electronics such as a flexible liquid crystal display, that would allow the background image to be displayed on the material itself, however, this elusive goal is no longer purely imaginary. 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 the cloth using an external projector. They can even reflect images when the material is wrinkled. The same year Time magazine named it the coolest invention of 2003. It is an interesting application of optical camouflage and is called the Invisibility Cloak. Through the clever application of some dirt-cheap technology, the Japanese inventor has brought personal invisibility a step closer to reality. Their prototype uses an external camera placed behind the cloaked object to record a scene, which it then transmits to a computer for image processing. The key development of the cloak, however, was the development of a new material called retro- reflectum. Professor Tachi says that this material allows you to see a three-dimensional image. The computer feeds the image into an external projector which projects the image onto a person wearing a special retro reflective coat. This can lead to different results depending on the quality of the camera, the projector, and the coat, but by the late nineties, convincing illusions were created. That was only one invention created in this field and researches are still being carried out in order to implement it using nanotechnology.
INTRODUCTION
Invisibility has been on humanity's wish list at least since Amon-Ra, a deity who could disappear and reappear at will, joined the Egyptian pantheon in 2008 BC. With recent advances in optics and computing and with the advent of flexible electronics such as a flexible liquid crystal display, that would allow the background image to be displayed on the material itself, however, this elusive goal is no longer purely imaginary. 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 the cloth using an external projector. They can even reflect images when the material is wrinkled. The same year Time magazine named it the coolest invention of 2003. It is an interesting application of optical camouflage and is called the Invisibility Cloak. Through the clever application of some dirt-cheap technology, the Japanese inventor has brought personal invisibility a step closer to reality. Their prototype uses an external camera placed behind the cloaked object to record a scene, which it then transmits to a computer for image processing. The key development of the cloak, however, was the development of a new material called retro- reflectum. Professor Tachi says that this material allows you to see a three-dimensional image. The computer feeds the image into an external projector which projects the image onto a person wearing a special retro reflective coat. This can lead to different results depending on the quality of the camera, the projector, and the coat, but by the late nineties, convincing illusions were created. That was only one invention created in this field and researches are still being carried out in order to implement it using nanotechnology.
