Modeling corneal surfaces with rational functions for high-speed videokeratoscopy data compression

Schneider, Martin, Iskander, Robert, & Collins, Michael J. (2009) Modeling corneal surfaces with rational functions for high-speed videokeratoscopy data compression. IEEE Transactions on Biomedical Engineering, 56(2), pp. 493-499.

View at publisher


High-speed videokeratoscopy is an emerging technique that enables study of the corneal surface and tear-film dynamics. Unlike its static predecessor, this new technique results in a very large amount of digital data for which storage needs become significant. We aimed to design a compression technique that would use mathematical functions to parsimoniously fit corneal surface data with a minimum number of coefficients. Since the Zernike polynomial functions that have been traditionally used for modeling corneal surfaces may not necessarily correctly represent given corneal surface data in terms of its optical performance, we introduced the concept of Zernike polynomial-based rational functions. Modeling optimality criteria were employed in terms of both the rms surface error as well as the point spread function cross-correlation. The parameters of approximations were estimated using a nonlinear least-squares procedure based on the Levenberg-Marquardt algorithm. A large number of retrospective videokeratoscopic measurements were used to evaluate the performance of the proposed rational-function-based modeling approach. The results indicate that the rational functions almost always outperform the traditional Zernike polynomial approximations with the same number of coefficients.

Impact and interest:

12 citations in Scopus
Search Google Scholar™
10 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 30342
Item Type: Journal Article
Refereed: Yes
Keywords: Cornea, Keratrometry, Rational Functions, Zernike polynomials
DOI: 10.1109/TBME.2008.2006019
ISSN: 0018-9294
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Optometry & Vision Science
Deposited On: 25 Feb 2010 21:57
Last Modified: 08 Jun 2016 05:50

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page