基于强度传输方程的多重网格算法

Multigrid Algorithm Based on Transport of Intensity Equation

为了从直接测量得到的强度图像中恢复相位信息,研究了基于强度传输方程的多重网格算法.从最粗层开始计算,给定初值,迭代出一个解,将此解作为最细层的初值,然后在最细层计算出一个近似解.进一步计算其残差,并将残差限制到较粗网格层求解,直至最粗层,然后逐层修正细网格层的解.利用循环在粗细不同的网格层来消除不同频率的误差分量,得到相位的精确解.仿真实验和真实实验表明,多重网格算法能够较好地从强度图像恢复物体的真实相位.

Multigrid algorithm based on the transport of intensity equation is researched to retrieval phase information from the intensity measurement. Given initial value and stared from the coarsest grid, a solution is obtained by calculating; regarded it as the finest initial value, an approximate solution is obtained by calculating; then its residual is calculated and it is restricted to coarser grid and solving, until to the coarsest grid, followed by corrected the solution of finer grid. Finally, different frequency error components are eliminated by cycle which on different sizes grids, and the accurate solution is obtained. The simulation and real experiments show that the multigrid algorithm can well retrieve the actual phase of the ob）ect from the intensity image.