Reciprocal focus profile
© 2011 IEEE
| Veröffentlicht in: | IEEE transactions on image processing : a publication of the IEEE Signal Processing Society. - 1992. - 21(2012), 2 vom: 15. Feb., Seite 459-68 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | IEEE transactions on image processing : a publication of the IEEE Signal Processing Society |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't |
| Zusammenfassung: | © 2011 IEEE A focus profile having a steeper peak is more resistant to image noise in the autofocus (AF) process of a digital camera. However, a focus profile of such shape normally has a flatter out-of-focus region on either side of the profile, resulting in a slow AF process due to the lack of clue about where the lens should move when the lens is in such regions. To address the problem, we provide a statistical analysis of the focus profile and show that a strictly monotonic transformation of the focus profile preserves the accuracy of the AF. On the basis of this analysis, we propose a new focus profile representation that transforms the focus profile to the reciprocal domain in which the reciprocal focus profile is modeled by a polynomial function. This transformation makes the AF mathematically tractable and boosts the search speed. Experimental results are shown to demonstrate the advantage of the proposed representation |
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| Beschreibung: | Date Completed 16.05.2012 Date Revised 20.01.2012 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1941-0042 |
| DOI: | 10.1109/TIP.2011.2164417 |