Abstract:The illumination coherence in augmented reality isan important means that makes virtual objects get realistic. It can make thecomputergenerated virtual objects blend into the real scene In order toarchieve the illumination coherence of augmented reality

this paper modifiesthe present algorithm and proposes a algorithm based on single tag This newmethod collects the brightness of the identification marking in any directionto make sure which direction the light source might be; it compares thebrightness of the identification marking with the brightness of the virtualobjects to ensure the brightness of the light source; it determines the colorof the light source by getting the color of the marker portion of no inkjetExperiments show that in meet the realtime and stability at the same time

theaverage angle between the virtual light source which is estimated by using thealgorithm in this paper and the true source is 43 degrees

and the virtualobjects can correctly cast shadows