Study on coma aberration correction technique for imaging systems of optical and electron microscope by the use of image processing

本研究是基于过去对“科研资助”的研究结果。本研究旨在建立透射电子显微镜彗差和高阶反对称波像差的校正理论。基于此，将三维成像理论推广到反对称波像差的情况，得到了一种广义的彗差校正理论。在本研究的第一阶段（1999年），我们提出了一个简单的傅立叶空间的校正滤波器。利用扩展的三维成像理论，对彗差校正进行了计算机模拟，以研究非线性成像项对彗差校正的影响 ...更多信息 不适用。在该模拟中，对于相位延迟大于1/20 λ的相位物体，非线性成像项的影响开始显现出来。下一阶段（2000年）进行了实时在线彗差校正装置的系统设计和程序编码。由于程序编码的困难，设计了一个局域网连接的独立在线校正系统，用于视频图像采集和彗差校正，而不是原来预期的使用一台PC机的集成系统。所构造的在线慧形像差校正装置的处理速率为约30秒/帧。虽然与第一目标值（几帧/秒）相比，该处理速率非常低，但在本研究中很好地证实了在线慧形像差校正器的其他特性。我们将重新规划系统设计，使其成为使用一台PC的集成系统。少

The present study is based on results of past studies of 'Grant-in-aid for scientific research'. The aim of this study is the establishment of the aberration correction theory for coma and higher order anti-symmetric wave aberrations in transmission electron microscopes. And also, the construction of a real-time on-line coma aberration correction apparatus, based on the image processing, is the second aim of this study.According to these aims, a generalized aberration correction theory for coma aberration was obtained by extending the tree dimensional (3D) imaging theory to the case of the anti-symmetric wave aberration. And a simple correction filter in the Fourier space, derived from this aberration correction theory, is proposed in the first stage (1999) of this study. Using the extended 3D imaging theory, computer simulations of the coma aberration correction were also achieved to examine the influence of the non-linear imaging terms in which the present coma aberration correction … More is not applicable. In this simulation, the influence of non-linear imaging terms begun to exhibit obvious for phase objects of the phase delay greater than 1/20 λ.The present coma aberration correction filter is based on the simple 2D phase correction in the Fourier space. The system design and the program coding of the real-time on-line coma aberration correction apparatus were carried out in the next stage (2000). By the reason of difficulties on the program coding, a LAN connected separate on-line correction system was designed for the video image acquisition and the coma aberration correction, instead of the integrated system using one PC, originally expected. The processing rate of the constructed on-line coma aberration correction apparatus was about 30 sec/frame. Although this processing rate is very low compared with the first aimed value (several frames / second), other characteristics as the online coma aberration corrector were well confirmed in this study. We will be re-planning the system design as an integrated system using one PC. Less