To increase the realism in rendering, estimating the illumination in the scene is a key element. A lot of works tackle this problem but rarely discuss the color of the reconstructed illumination. The Dichromatic Model indicates that the specular component is not affected in color by the texture underneath and holds the light source’s color. Though theoretically sound, in practice consumer cameras are subject to nonlinear behaviors which change RGB ra- tios and create inconsistencies when estimating the illumination. In this paper, we study the conditioning and limits of inverting local illumination models while relying on the Dichromatic Model. We show that the reconstructed specular component has an inconsis- tent color because it changes depending on the surface’s colors.

We propose dual JOLIMAS, a new model which raises the planarity assumption. It uses the fact that specularities remain elliptical on convex surfaces and that every surface can be divided in convex parts. The geometry of dual JOLIMAS then uses a 3D quadric per convex surface part and light source, and predicts the specularities by a means of virtual cameras, allowing it to cope with surface’s unflatness.

This paper highlights our empirical model called JOLIMAS (JOint LIght-MAterial Specularity) which is used to predict specularities in real-time on planar surfaces. We used this model to perform retexturing on several objects. The novelty of paper compared to our previous approach is the handling of multiple light sources of different intensities. Moreover, light sources can be turned on and off.

This paper highlights our empirical model called JOLIMAS (JOint LIght-MAterial Specularity) which is used to predict specularities in real-time on planar surfaces. We used this model to perform retexturing on several objects.

We proposed a real-time method for specularity prediction. The novelty of the approach was the use of a pre-treatment step to level the brightness of the image, a thresholding process according to the brightness of the image and a post-processing step which use the gradient aspect of a specularity.