Kanmani B, Vasu R M
Department of Telecommunication Engineering, BMS College of Engineering, Bangalore 560 019, India.
Phys Med Biol. 2007 Mar 7;52(5):1409-29. doi: 10.1088/0031-9155/52/5/013. Epub 2007 Feb 9.
An iterative reconstruction procedure is used to invert intensity data from both single- and phase-correlated dual-source illuminations for absorption inhomogeneities. The Jacobian for the dual source is constructed by an algebraic addition of the Jacobians estimated for the two sources separately. By numerical simulations, it is shown that the dual-source scheme performs superior to the single-source system in regard to (i) noise tolerance in data and (ii) ability to reconstruct smaller and lower contrast objects. The quality of reconstructions from single-source data, as indicated by mean-square error at convergence, is markedly poorer compared to their dual-source counterpart, when noise in data was in excess of 2%. With fixed contrast and decreasing inhomogeneity diameter, our simulations showed that, for diameters below 7 mm, the dual-source scheme has a higher percentage contrast recovery compared to the single-source scheme. Similarly, the dual-source scheme reconstructs to a higher percentage contrast recovery from lower contrast inhomogeneity, in comparison to the single-source scheme.
一种迭代重建程序用于从单源和相位相关双源照明的强度数据中反演吸收不均匀性。双源的雅可比矩阵通过分别为两个源估计的雅可比矩阵的代数相加来构建。通过数值模拟表明,在(i)数据中的噪声容忍度和(ii)重建更小和对比度更低的物体的能力方面,双源方案比单源系统表现更优。当数据中的噪声超过2%时,从收敛时的均方误差来看,单源数据重建的质量明显比双源对应数据差。在固定对比度和减小不均匀性直径的情况下,我们的模拟表明,对于直径小于7毫米的情况,与单源方案相比,双源方案具有更高的对比度恢复百分比。同样,与单源方案相比,双源方案从对比度更低的不均匀性中重建出的对比度恢复百分比更高。