Image-based Dynamic Lighting Control

In taking an image, it is important to shoot target objects under an appropriate lighting. If the lighting is inappropriate, the target objects become too dark or too bright in the taken images and the details of the objects cannot be seen. We propose a method to control lighting automatically to keep the image brightness of the target objects within the dynamic range of the camera. In our method, a background image under arbitrary lighting is synthesized from a set of images obtained under different lighting. The generated background image is used to extract the image regions that correspond to the target object. The intensity of the lights is dynamically controlled so that the target objects are shot under an appropriate lighting by observing the brightness of the extracted foreground pixels. Because this method controls the intensity of the lights based only on the brightness of the taken images, it is needless to recover 3D information and reflectance properties of any objects in the room. We present some experimental results to show the effectiveness of our method.