An improved image alignment procedure for high-resolution transmission electron microscopy |
| |
| Authors: | Fang Lin Yan Liu Xiaoyan Zhong Jianghua Chen |
| |
| Institution: | 1. College of Science, South China Agricultural University, GuangZhou, GuangDong 510642, China;2. Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA;3. Center for High-Resolution Electron Microscopy, College of Material Science and Engineering, Hunan University, Changsha, Hunan 410082, China;1. Nuclear Science and Technology Development Center, National Tsing Hua University, 101, Sect. 2, Kuang Fu Road, Hsinchu 30013, Taiwan, ROC;2. Department of Engineering and System Science, National Tsing Hua University, 101, Sect. 2, Kuang Fu Road, Hsinchu 30013, Taiwan, ROC;1. Meteorological Research Division, Environment Canada, Dorval, Quebec H9P 1J3, Canada;2. Department of Mechanical and Materials Engineering, The University of Western Ontario, London, Ontario N6A 5B9, Canada;1. Institute of Materials Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan, ROC;2. United Microelectronics Corporation, Xinshi Dist., Tainan City 74147, Taiwan, ROC;3. Institute of Technical Research Industries, Hsin-Chu 31005, Taiwan, ROC;1. Department of Mechanical Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada;2. Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA |
| |
| Abstract: | Image alignment is essential for image processing methods such as through-focus exit-wavefunction reconstruction and image averaging in high-resolution transmission electron microscopy. Relative image displacements exist in any experimentally recorded image series due to the specimen drifts and image shifts, hence image alignment for correcting the image displacements has to be done prior to any further image processing. The image displacement between two successive images is determined by the correlation function of the two relatively shifted images. Here it is shown that more accurate image alignment can be achieved by using an appropriate aperture to filter the high-frequency components of the images being aligned, especially for a crystalline specimen with little non-periodic information. For the image series of crystalline specimens with little amorphous, the radius of the filter aperture should be as small as possible, so long as it covers the innermost lattice reflections. Testing with an experimental through-focus series of Si1 1 0] images, the accuracies of image alignment with different correlation functions are compared with respect to the error functions in through-focus exit-wavefunction reconstruction based on the maximum-likelihood method. Testing with image averaging over noisy experimental images from graphene and carbon-nanotube samples, clear and sharp crystal lattice fringes are recovered after applying optimal image alignment. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
