3D reconstruction technology of SMT solder joint by shape from shading based on improved illumination model

Three-dimensional shape and its accuracy are dissatisfactory because of the highlight caused by specular reflection when the shape from shading is used to reconstruct the three-dimensional soldered joint.An improved illumination model is proposed, which can modify the diffuse reflectance component based on the features of image shooting, make a linear superposition for both specular reflection component and diffuse reflectance component.Then the improved illumination model is used to reconstruct the three-dimensional soldered joint after dealing with the soldered joint image by the proper image processing arithmetic.The experimental results show that the 3D shape by SFS based on the improved illumination model is more satisfactory in decreasing specular reflection influence than that of the traditional methods.