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Light fields and computation

al photography

Overview The light field, first described in Arun Gershun's classic 1936 paper of the same name, is defined as radiance as a function of position and direction in regions of space free of occluders. In free space, the light field is a 4D function - scalar or vector depending on the exact definition employed. Light fields were introduced into computer graphics in 1996 by Marc Levoy and Pat Hanrahan. Their proposed application was image-based-rendering - computing new views of a scene from pre-existing views without the need for scene geometry. (A workshop on image-based modeling and rendering was held at Stanford in 1998.)

WikiLeaks: The Spy Files

Mass interception of entire populations is not only a reality, it is a secret new industry spanning 25 countries

International surveillance companies are based in the more technologically sophisticated countries, and they sell their technology on to every country of the world. This industry is, in practice, unregulated. Intelligence agencies, military forces and police authorities are able to silently, and on mass, and secretly intercept calls and take over computers without the help or knowledge of the telecommunication providers. Users’ physical location can be tracked if they are carrying a mobile phone, even if it is only on stand by.