Optical%20Camouflage

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Optical Camouflage

• Presented by,
• PRAVIN. M
• R745

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This is what it really does
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What is Optical Camouflage??

• It is developed by three scientists at the
  university of Tokyo.
• Camouflage means to blend with the surroundings.
• Optical Camouflage is a kind of camouflage in
  which, one wears a cloth which projects the
  background so that he appears somehow invisible.
• It provides invisibility only in the visible
  portion of the spectrum.

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Retro-reflective Material

• The cloak that enables, optical Camouflage to
  work is made from a special material known as
  retro-reflective material.
• Retro-reflective material is covered with
  thousands of small beads.
• When light rays strike any of these beads, they
  are reflected back exactly in the same direction
  from which they came.

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Light Surface Reflectivity
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Retro-reflectivity

• In retro reflection the glass beads act like
  prism, bending the light rays by a process known
  as refraction.
• An observer situated at the light source receives
  more of the reflected light and hence a brighter
  reflection.

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Principle of Optical Camouflage

• Optical camouflage works by taking advantage of
  something called augmented-reality technology.
• Augmented reality systems add computer generated
  information to a users sensory perceptions.
• Augmented reality systems are not the same as
  virtual reality systems.
• Augmented reality systems require that the users
  view through a special viewing apparatus.

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REQUIREMENTS

• A garment made from retro-reflective material.
• A video camera.
• A computer.
• A projector.
• A special half silvered mirror called a combiner.

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• Combiner
• It is also called beam-splitter.
• It reflects the projected image towards cloak.
• It lets light rays bouncing of the cloak to the
  users eye.
• Allows the user to perceive both image enhanced
  by computer and surrounding light.
• Both computer generated image and real world
  scene must be fully integrated.

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The Complete System
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How does it work??

• The person who wants to be invisible wears the
  cloak made of retro-reflective material.
• A digital video camera captures the scene behind
  the person wearing the cloak.
• The computer processes the captured image.
• The projector receives the enhanced image from
  the computer and shines the image through a
  pin-hole sized opening onto the combiner.
• contd. . .

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How does it work??

• The silver half of the mirror which is completely
  reflective, bounces the projected image towards
  the person wearing the cloak.
• The cloak reflects light directly back to the
  mirror.
• Light rays bouncing off of the cloak pass through
  the transparent part of the mirror and falls on
  the users eye.
• Hence, the person wearing the cloak appears
  partially invisible.

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Real World Applications

• Pilots landing a plane could use this technology
  to make the cockpit floors transparent.
• This enables them to see the runway simply by
  glancing down.

Contd. . .
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Real World Applications

• Drivers backing up cars could benefit from
  optical camouflage.
• A quick glance backward through a transparent
  rear would make it easy to know when to stop.

Contd. . .
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Real World Applications

• Doctor performing surgery could see through their
  hands and instruments to the underlying tissues.
• Providing a view of the outside in a windowless
  room.
• Mutual Telexistence.

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Mutual telexistence

• Working and perceiving with the feeling that you
  are in several places at once.
• Real-time video of separated individuals is
  projected onto surrogate robotic participants.
• This is done via sophisticated communication
  technology.

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Diagram of Mutual Telexistence
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Where have you seen Optical Camouflage in
fiction??

• James Bond film Die Another Day.
• Arnold Schwarzenegger film Predator.
• Doom video game series.
• Metal gear Solid video game series.
• Halo video game series.
• In Japanese animation series Ghost in the shell.

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Future Outlook

• It requires suit covered in tiny cameras and
  projectors.
• It should be programmed to gather visual data
  from different angles and project them in equally
  large number of directions.
• It would require a massive amount of computing
  power and embedded sensors.
• Sophisticated nanotechnology will be required.

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Drawbacks

• Large amount of external hardware required.
• Only partial invisibility is achieved.
• Target can only be in a certain point of view.
• Observer need to look through a combiner.
• Current system needs half mirror and projector,
  which are fixed on the ground.

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Conclusion

• Now all of us have had a small tour of the
  interesting world of Optical camouflage.
• Optical Camouflage is a technology which is
  currently in a very primitive stage of
  development and hence have many drawbacks.
• Research work is going on and soon we will have
  even more astonishing results.
• This technology is believed to have a significant
  role in the future world. . .

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THANK
YOU. . .
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ANY QUERIES?