Optical Camouflage Analysis

ABSTRACT:- Invisibility are heard in stories but it is made true using optical camouflage, image based-rendering, retro-reflective material. The object is made transparent by painting with retro-reflective material. The background image is projected using the projector making it virtually transparent. Video camera captures the background behind the masked object. Digital video camera should be used so that it can be sent to the computer for image processing
KEYWORDS :
Optical camouflage ,retro reflective material.
I. INTRODUCTION
Optical camouflage is a active camouflage. The concept is simple. If the background image is projected on the object painted with retro reflective material, it creates invisibility. Digital Video camera, computer,

The masked object acts like a screen in which the background is projected using video camera. The format of the video should be digital for easy processing.
COMPUTER:
Powerful computers synthesize graphics and superimpose on real world image on augmented outputs. Computer reckons perspective to simulate the reality and modify the captured image into the image that will be projected on the clock. This technique is image based rendering.
PROJECTOR AND COMBINER:
PROJECTOR:
The transformed image must be shone on to the cloak. The image is sent through an opening controlled by iris diaphragm .Its is made of thin opaque plates and rings to change the diameter. The size of the opening must be in the size of the pin hole to ensure larger depth of field. larger field depth allows the screen to be located at any difference from the projector.
COMBINER:
A special mirror known as a combiner or beam splitter is required for both reflection and transmission .silvered half of mirror reflects the light while the other transparent half transmits light.the combiner must be properly positioned to view the image processed by the computer.the cloak and the background image must be fully integrated for realistic

The computer gives the processed image to the computer and sends it through the iris diaphragm on to the combiner.th silvered half is completely reflective and project the image to the image to the cloak. The cloak acts as a movie screen and reflects light back to the source. Light rays from the cloak pass through the transparent mirror and reach the user. These rays contain the background scene. Object covered with the retro reflective material appears invisible due to the background scene which is being display on it HEAD-MOUNTED DISPLAYS :
HMD is a wearable device capable of projecting images and helps the user to see through it
HMD display assemble combiner and optics in a mobile device .two types of HMD exists; optical see through displays and video see through displays. The former looks like hi-tech goggles. These goggles provide the display and optics for each eye to provide a stereoscopic effect. Video see through displays combines camera image with computer graphics. The combined is presented on a LCD displays. Video see through displays can make virtual object fully obscure real world objects VII.REAL-WORLD APPLICATIONS
While an invisibility cloak is an interesting application of optical camouflage, it's probably not the most useful one. Here are some practical ways the technology might be