相位解码的时-空重建算法

基于相位映射的三维传感技术对几何形状和拓扑结构复杂或表面梯度很大的物体进行绝对相位测量及相位重建仍然是一个困难的问题。近年来国际上提出了一种时间维度相位重建算法可以对此提供一种解决方案。然而,该算法对结构光照明系统提出了很高的要求,当系统无法满足算法要求时,重建结果存在严重的噪声。针对这一问题,提出了一种利用分段函数构造的相位解码的时空重建算法。该算法在相位重建过程中同时考虑时间维度和空间维度相位的相对关系,使得空间频率非严格按指数增长的条纹序列可以得到正确的重建,消除了跳变边界的相位模糊问题,从而可以更加有效地解决深度表面不连续和存在相互孤立物表面拓扑结构的景物相位重建问题。实验结果证明了此算法的可行性和有效性。

Phase Decoding Based On Temporal-Spatial Phase Unwrapping

Absolute phase measurement and phase reconstruction to object surfaces with complex geometric and topologic shapes still remain difficult for phase mapping based on three-dimensional(3D) sensing.Recently,an approach based on temporal phase unwrapping has been proposed to handle this task.However,it is found from the experiment that temporal phase unwrapping imposed severe restriction to the illumination system of structured light.If the required condition is not satisfied,the temporal phase unwrapping will cause severe noise in the reconstructed phase map.To overcome this problem,a new approach based on spatial and temporal phase unwrapping is presented,which is constructed with piece-wise functions by taking both temporal and spatial factors into account during the process of phase reconstruction.This leads to the effective phase reconstruction even under the situation that the number of fringes is not exact the integer exponential of power 2,which is an essential restriction imposed on previous temporal phase unwrapping algorithm.The approach eliminates the problem of phase ambiguity at the boundaries of phase jump corresponding to the wrapped phase map and therefore provides a more efficient solution to the phase reconstruction of 3D object surfaces with complex geometric and topologic shapes or to a scene with isolated objects.Experimental results have demonstrated the proposed approach.