Use of polarized light in image analysis: Application to the analysis of fish eye color during storage

Balaban M. O., Alcicek Z.

LWT-FOOD SCIENCE AND TECHNOLOGY, vol.60, no.1, pp.365-371, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 60 Issue: 1
  • Publication Date: 2015
  • Doi Number: 10.1016/j.lwt.2014.09.046
  • Journal Name: LWT-FOOD SCIENCE AND TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.365-371
  • Keywords: Machine vision, QIM, Image analysis, Fish eye, METHOD QIM SCHEME, THERAGRA-CHALCOGRAMMA ROE, QUALITY EVALUATION, SHELF-LIFE, FILLETS, FRESHNESS, L.
  • Çanakkale Onsekiz Mart University Affiliated: Yes

Abstract

The evaluation of the eye is one method to determine the state of the fish: it is expected that the eye will start as black, transparent, and convex, and during storage it will become progressively lighter in color, more opaque, and will be sunken. Image analysis is an objective method to measure color. In this study, a method was developed to define a region of interest within the image of the eye, and to analyze its color. The effects of using polarized or non-polarized illumination, the dry or wet condition of the fish, and the eye touching ice during storage or being only exposed to air were determined. The L* values of the eye of the fish on the side touching the ice behaved as expected: L* values increased during storage for 7 or 11 days. However, the eye exposed only to air during storage on ice had significantly lower L* values. Wet or dry conditions did not affect L* values, however the eyes illuminated by non-polarized light had higher L* values than those illuminated by polarized lighting. These results should be considered when developing subjective or automated methods to evaluate fish by examination of their eyes.

The evaluation of the eye is one method to determine the state of the fish: it is expected that the eye will start as black, transparent, and convex, and during storage it will become progressively lighter in color, more opaque, and will be sunken. Image analysis is an objective method to measure color. In this study, a method was developed to define a region of interest within the image of the eye, and to analyze its color. The effects of using polarized or non-polarized illumination, the dry or wet condition of the fish, and the eye touching ice during storage or being only exposed to air were determined. The L* values of the eye of the fish on the side touching the ice behaved as expected: L* values increased during storage for 7 or 11 days. However, the eye exposed only to air during storage on ice had significantly lower L* values. Wet or dry conditions did not affect L* values, however the eyes illuminated by non-polarized light had higher L* values than those illuminated by polarized lighting. These results should be considered when developing subjective or automated methods to evaluate fish by examination of their eyes. (C) 2014 Elsevier Ltd. All rights reserved.