Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope.
| dc.contributor.author | Nicolls, F | |
| dc.contributor.author | de Jager, G | |
| dc.contributor.author | Sewell, B | |
| dc.date.accessioned | 2016-07-29T10:08:53Z | |
| dc.date.available | 2016-07-29T10:08:53Z | |
| dc.date.issued | 1997 | |
| dc.date.updated | 2016-07-29T08:09:41Z | |
| dc.description.abstract | This work outlines the development of a general imaging model for use in autofocus, astigmatism correction, and resolution analysis. The model is based on the modulation transfer function of the system in the presence of aberrations, in particular, defocus. The signals used are related to the ratios of the Fourier transforms of images captured under different operating conditions. Methods are developed for working with these signals in a consistent manner. The model described is then applied to the problem of autofocus. A fairly general autofocus algorithm is presented and results given which reflect the predictive properties of this model. The imaging system used for the generation of results was a scanning electron microscope (SEM), although the conclusions should be valid across a far wider range of instruments. It is, however, the specific requirements of the SEM that make the generalisation presented here particularly useful. We have, therefore, confined our investigation to SEM. | en_ZA |
| dc.identifier | http://dx.doi.org/10.1016/S0304-3991(97)00028-4 | |
| dc.identifier.apacitation | Nicolls, F., de Jager, G., & Sewell, B. (1997). Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope. <i>Ultramicroscopy</i>, http://hdl.handle.net/11427/21018 | en_ZA |
| dc.identifier.chicagocitation | Nicolls, F, G de Jager, and B Sewell "Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope." <i>Ultramicroscopy</i> (1997) http://hdl.handle.net/11427/21018 | en_ZA |
| dc.identifier.citation | Nicolls, F. C., De Jager, G., & Sewell, B. T. (1997). Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope. Ultramicroscopy, 69(1), 25-37. | en_ZA |
| dc.identifier.issn | 0304-3991 | en_ZA |
| dc.identifier.ris | TY - Journal Article AU - Nicolls, F AU - de Jager, G AU - Sewell, B AB - This work outlines the development of a general imaging model for use in autofocus, astigmatism correction, and resolution analysis. The model is based on the modulation transfer function of the system in the presence of aberrations, in particular, defocus. The signals used are related to the ratios of the Fourier transforms of images captured under different operating conditions. Methods are developed for working with these signals in a consistent manner. The model described is then applied to the problem of autofocus. A fairly general autofocus algorithm is presented and results given which reflect the predictive properties of this model. The imaging system used for the generation of results was a scanning electron microscope (SEM), although the conclusions should be valid across a far wider range of instruments. It is, however, the specific requirements of the SEM that make the generalisation presented here particularly useful. We have, therefore, confined our investigation to SEM. DA - 1997 DB - OpenUCT DP - University of Cape Town J1 - Ultramicroscopy LK - https://open.uct.ac.za PB - University of Cape Town PY - 1997 SM - 0304-3991 T1 - Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope TI - Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope UR - http://hdl.handle.net/11427/21018 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/21018 | |
| dc.identifier.vancouvercitation | Nicolls F, de Jager G, Sewell B. Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope. Ultramicroscopy. 1997; http://hdl.handle.net/11427/21018. | en_ZA |
| dc.language | eng | en_ZA |
| dc.publisher | Elsevier | en_ZA |
| dc.publisher.institution | University of Cape Town | |
| dc.rights | Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) | * |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | en_ZA |
| dc.source | Ultramicroscopy | en_ZA |
| dc.source.uri | https://www.elsevier.com/search-results?query=Ultramicroscopy&labels=all | |
| dc.subject.other | Scanning electron microscope (SEM) | |
| dc.subject.other | Automatic focus | |
| dc.subject.other | Autofocus | |
| dc.subject.other | Depth-from-defocus (DFD) | |
| dc.subject.other | Modulation | |
| dc.title | Use of a general imaging model to achieve predictive autofocus in the scanning electron microscope. | en_ZA |
| dc.type | Journal Article | en_ZA |
| uct.type.filetype | Text | |
| uct.type.filetype | Image | |
| uct.type.publication | Research | en_ZA |
| uct.type.resource | Article | en_ZA |