Improved reconstruction accuracy of photometric stereo technique based on control points

A 3D surface with better accuracy can be achieved by using the gradient information recovered from the photometric stereo technique.However the results usually demonstrate bias or distortion across the whole scene due to inherent error accumulation in the reconstruction procedure.A method is presented to improve global accuracy through some control points whose positions are known in prior.Firstly,the accurate 3D coordinates of control points are obtained by laser triangulation,and then the weighted least squares method and interpolation surface method are used to obtain the 3D shape of the object.The experiments are implemented on a synthetic sphere and proved that the interpolation surface method is a better solution in terms of reconstruction accuracy.