Illumination Techniques in Augmented Reality for Cultural Heritage

Augmented reality technology is becoming important in developing visual representation of virtual environment. In augmented reality environment, the most difficult problem is to render the virtual object with illumination which is consistent with the illumination and shadow of the real environment. Without the consistent illumination, the realism of augmented reality environment will be reduced. Recently, a lot of researchers developed new techniques to improve the quality of illumination in augmented reality. This paper presents an overview of the available illumination techniques in augmented reality environment. Three classification techniques were presented which is common illumination, relighting and inverse illumination. The used of the techniques depends on input requirement of the user that appropriate with the projects.