20 November 1989 An Assessment Of Some Image Enhancement Routines For Use With An Automatic Fringe Tracking Programme
Author Affiliations +
An automatic fringe tracking programme has been developed for use with holographic interferograms obtained for heat transfer and compressible flow studies at the City University Thermofluids Laboratory. This paper reviews the image enhancement routines which were considered for use to prepare images prior to the application of fringe tracking and fringe ordering procedures. Their relative performances are assessed qualitatively and the conclusions which were reached in these studies are presented. Data pre-processing aspects such as image masking and the selection and implementation of common point or fiducial marking are also described. An important aspect of the work described has been the necessity of operating with an optimised level' of image enhancement, trading off processing time and hardware costs against usable image quality. Maximum entropy and statistical enhancement methods were rejected in favour of more direct and speedier methods. The heat transfer experiments were carried out with more primitive equipment than that used for the compressible flow studies, yielding poorer quality raw data, so that a much more extensive image enhancement regime was required before adequate data was available for the fringe detection routines. The paper details the different routines required in these two cases, illustrating how experimental sophistication can be traded against image processor costs and processing time.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. C. Hunter, M. W. Collins, B. A. Tozer, "An Assessment Of Some Image Enhancement Routines For Use With An Automatic Fringe Tracking Programme", Proc. SPIE 1163, Fringe Pattern Analysis, (20 November 1989); doi: 10.1117/12.962785; https://doi.org/10.1117/12.962785


Back to Top