EINABADI, GRAU: DISCRETE LIGHT SOURCE ESTIMATION FROM LIGHT PROBES 1 Discrete Light Source Estimation from Light Probes for Photorealistic Rendering

This contribution describes a new technique for estimation of discrete spot light sources. The method uses a consumer grade DSLR camera equipped with a fisheye lens to capture light probe images registered to the scene. From these probe images the geometric and radiometric properties of the dominant light sources in the scene are estimated. The first step is a robust approach to identify light sources in the light probes and to find exact positions by triangulation. Then the light direction and radiometric fall-off properties are formulated and estimated in a least square minimization approach. The new method shows quantitatively accurate estimates compared to ground truth measurements. We also tested the results in an augmented reality context by rendering a synthetic reference object scanned with a 3D scanner into an image of the scene with the estimated light properties. The rendered images give photorealistic results of the shadow and shading compared to images of the real reference object.