Genetic algorithms applied to reconstructing coded imaging of neutrons and analysis of residual watermark.
Genetic algorithms applied to reconstructing coded imaging of neutrons and analysis of residual watermark.
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DOI：
10.1063/1.4765701
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发表时间：
2012-11
期刊：
影响因子：
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通讯作者：
Tiankui Zhang;Huasi Hu;Q. Jia;Fengna Zhang;Da Chen;Zhenghong Li;Yue-lei Wu;Zhihua Liu;Guang Hu;Wei Guo
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文献类型：
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作者：
Tiankui Zhang;Huasi Hu;Q. Jia;Fengna Zhang;Da Chen;Zhenghong Li;Yue-lei Wu;Zhihua Liu;Guang Hu;Wei Guo
采用蒙特-卡罗方法，对半径为5 mm的大视场Z箍缩中子编码成像进行了模拟，得到了编码图像。建立了基于遗传算法的源图像重建方法。在遗传算法适应度计算中采用峰值归一化时，由于其统计波动放大作用，在重构图像中必然会出现“残留水印”。残留水印主要与编码孔径截面的形状等参数有关。分析了残留水印的性质和产生的根本原因，并给出了等效孔径半径的鉴别方法。利用该等效半径，可以在不知道实际孔径的点扩散函数的情况下实现重构。重建结果与利用实际孔径点扩展函数得到的结果接近。
Monte-Carlo simulation of neutron coded imaging based on encoding aperture for Z-pinch of large field-of-view with 5 mm radius has been investigated, and then the coded image has been obtained. Reconstruction method of source image based on genetic algorithms (GA) has been established. "Residual watermark," which emerges unavoidably in reconstructed image, while the peak normalization is employed in GA fitness calculation because of its statistical fluctuation amplification, has been discovered and studied. Residual watermark is primarily related to the shape and other parameters of the encoding aperture cross section. The properties and essential causes of the residual watermark were analyzed, while the identification on equivalent radius of aperture was provided. By using the equivalent radius, the reconstruction can also be accomplished without knowing the point spread function (PSF) of actual aperture. The reconstruction result is close to that by using PSF of the actual aperture.