Active lighting for object brightness control

We present an active lighting method that can control brightness of multiple objects in a scene to any values on video images. Our approach does not modify pixel values such as in retouching but changes intensities of multiple lights in the scene. Our algorithm needs little computation to calculate appropriate intensities of the lights because we formulate the brightness of the objects so that the essential parameters in our formulation can be measured in advance. We have implemented a prototype system that can control brightness of faces of two people in a room to intended values with eight controllable lights as they are walking.