CAJ | 학술논문

网格算法是最常见的衍射层析成像的频域重建算法，然而这种算法却容易引入误差，且对采样点的分布形状较敏感，因此，本文提出了一种基于 Voronoi 图密度补偿的超声衍射层析成像重建算法．首先，用三角剖分快速生成算法生成投影数据的 Voronoi 图，并对在外凸壳上对应的 Voronoi 图面积是无穷大的点通过拟合、插值处理使之变为有限的补偿面积，从而得到整个点集的补偿面积．其次，提出了基于 Voronoi 图面积密度补偿的衍射层析成像的非均匀傅里叶变换网格重建算法，重建图像的质量较没有补偿的有很大提高．最后，提出了选取1/4圆弧的数据集重建方案，实验结果表明：在重建质量相当的情况下，1/4圆弧的重建时间比1/2圆弧少27．32％．
망격산법시최상견적연사층석성상적빈역중건산법，연이저충산법각용역인입오차，차대채양점적분포형상교민감，인차，본문제출료일충기우 Voronoi 도밀도보상적초성연사층석성상중건산법．수선，용삼각부분쾌속생성산법생성투영수거적 Voronoi 도，병대재외철각상대응적 Voronoi 도면적시무궁대적점통과의합、삽치처리사지변위유한적보상면적，종이득도정개점집적보상면적．기차，제출료기우 Voronoi 도면적밀도보상적연사층석성상적비균균부리협변환망격중건산법，중건도상적질량교몰유보상적유흔대제고．최후，제출료선취1/4원호적수거집중건방안，실험결과표명：재중건질량상당적정황하，1/4원호적중건시간비1/2원호소27．32％．
A common way for image reconstruction in frequency domain is the gridding algorithm .However ,this approach is liable to introduce inaccuracies and is sensitive to the configuration of the sample points .So a new reconstruction method based on Voronoi diagrams is proposed in this paper .Firstly ,the projection data of Voronoi diagram is generated quickly based on triangula-tion algorithm ,data points on the convex shell with the infinite area of Voronoi diagram is turned into the finite compensation area by polynomial fitting and interpolation processing ,then all the data points obtained the compensation area of Voronoi diagram .Sec-ondly ,the reconstruction algorithm of diffraction tomography using NUFFT (non-uniform FFT) and the density compensation by the area of Voronoi diagram is proposed ,and the quality of reconstructed image has been greatly improved .Finally ,the results of simu-lation showed that there is 27 .32% less reconstructive time of 1/4 arc than the time of 1/2 arc in the case of considerable quality of reconstruction .