Two-step Light Source Detection Algorithm Importing the 3D Shadow and Specular Reflection

The inverse detection algorithms based on the illumination model are widely used in augmented reality,however their detection errors of the light source's position are relatively large,and they demand that the surface of the calibration object is purely diffuse.A two-step detection algorithm of the light source is proposed which imports 3-D features of the shadows and specular reflection.The algorithm is divided into two parts,position detection of the light source and intensity detection of the light.Under the condition of having known the position of the light source,the Cook-Torrance model with the specular reflection is imported,and such methods as random sampling partition and error handling are also adopted.Besides,the 3-D features of the shadow are used instead of the plane corner features,and the position of the light source is detected according to the ray tracing.Experiment results show that the position detected by this algorithm is more accurate.Therefore,it solves the inaccuracy in detecting the position of the point light source and the limitations in the calibration objects.