Light source separation from image sequences of oscillating lights

Light has a significant influence on the color of objects in the image. Sometimes scene light is comprised of mixture of several light sources, and this mixture makes it hard to achieve color constancy across the image. Having precise control over the intensity of the light sources at the capturing stage, can enable an easy light source separation by turning on a single light source for each captured frame. In other cases - prior knowledge on the cyclic behavior of the light intensity over time can be used instead, by describing each light source as a set of base functions. This enables the reconstruction of the light sources by means of inner multiplication of the video scene with the base functions. This analysis method assumes that the signal is linear, but this assumption fails when secularities or high illuminance values cause clipping or when low light conditions causes noise to be apparent in the image. By using a cyclic High Dynamic Range (HDR) sampling method the scene becomes linear and good reconstruction results are obtained. Two experiments are used to demonstrate the approach. The first shows the decomposition of two oscillating light sources and the second the decomposition of an oscillating light and sunlight.