Combination photometric stereo using compactness of albedo and surface normal in the presence of shadows and specular reflection

We present a novel combination photometric stereo which can estimate surface normals precisely even for images including shadows and specular reflection. We can use photometric stereo if there are more than three input images. Therefore we can employ photometric stereo with nC3 combinations for n input images. We make 3D distribution of albedos and surface normals estimated from pixel intensities of nC3 pixel combinations. In the distribution, we define a novel value “compactness” to distinguish pixels which are included in neither shadows nor specular reflection from pixels which are included in shadows or specular reflection. Through experimental results, we demonstrate that the proposed method can estimate surface normals in the presence of shadows and specular reflection. Moreover the proposed method is superior to previous works in better accuracy.