Cancelling bias induced by correlation coefficient interpolation for sub-pixel image registration
Accurate sub-pixel image registration has many applications in precision engineering and manufacturing. Due to its computational efficiency, correlation-based sub-pixel image registration is especially useful for real-time applications. This paper presents a theoretical analysis of the bias induced...
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Published in | Measurement science & technology Vol. 24; no. 3; pp. 35404 - 1-10 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
IOP Publishing
01.03.2013
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Subjects | |
Online Access | Get full text |
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Summary: | Accurate sub-pixel image registration has many applications in precision engineering and manufacturing. Due to its computational efficiency, correlation-based sub-pixel image registration is especially useful for real-time applications. This paper presents a theoretical analysis of the bias induced by correlation coefficient interpolation, when employed to achieve two-dimensional sub-pixel registration resolution. An analytical model of bias in terms of true sub-pixel image shift is first derived according to the given reference image model. It is then used to establish an accurate bias map expressed explicitly in terms of sub-pixel image shift estimated from coefficient interpolation. This bias map is readily employed to eliminate the bias error and to significantly improve measurement accuracy for real-time applications. A bias cancellation scheme was implemented and verified by means of both computer simulation and experimental results. Specifically, sub-nanometre measurement precision was experimentally demonstrated using a microscopic vision system implemented for real-time motion tracking. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0957-0233 1361-6501 |
DOI: | 10.1088/0957-0233/24/3/035404 |