Automatic measurement of the angle of squint by Hough-transformation and covariance-filtering

Author

Kaupp, Ansgar ; Lehmann, Thomas ; Effert, Rolf ; Meyer-Ebrecht, Dietrich

Author_Institution

Inst. for Meas. Technol., Aachen Univ. of Technol., Germany

Volume

1

fYear

1994

fDate

9-13 Oct 1994

Firstpage

784

Abstract

Describes the image processing method for the automatisation of the measurement of squint using the first and fourth Purkinje reflex. This method is already in use in clinical practice in comparison to the standard method of the cover test. The new method, based on image processing, allows the exact and objective determination of the angle of squint. Children from the age of six months as well as adults can be examined. The automatisation of the previously interactive method is a prerequisite for the screening of large collectives of children for microstrabism. The method uses a two-stage abstraction to identify six reflexes in the iris of each eye. The method based on the Hough-transform and covariance-filtering is robust against image distortions and additional reflexes, as produced by wearing glasses. The reliability of the method has been proven in 191 cases and is tested in routine use now

Keywords

eye; 0.5 y; Hough-transformation; automatic squint measurement; covariance-filtering; first Purkinje reflex; fourth Purkinje reflex; image distortion robustness; image processing; iris; microstrabism; reflex identification; Automatic testing; Digital images; Eyes; Goniometers; Image processing; Iris; Measurement standards; Object detection; Paper technology; Robustness;

fLanguage

English

Publisher

ieee

Conference_Titel

Pattern Recognition, 1994. Vol. 1 - Conference A: Computer Vision & Image Processing., Proceedings of the 12th IAPR International Conference on

Conference_Location

Jerusalem

Print_ISBN

0-8186-6265-4

Type

conf

DOI

10.1109/ICPR.1994.576442

Filename

576442