title: Automatic localization of the optic disc by combining vascular and intensity information.
abstract: This paper describes a new methodology for automatic location of the optic disc in retinal images, based on the combination of information taken from the blood vessel network with intensity data. The distribution of vessel orientations around an image point is quantified using the new concept of entropy of vascular directions. The robustness of the method for OD localization is improved by constraining the search for maximal values of entropy to image areas with high intensities. The method was able to obtain a valid location for the optic disc in 1357 out of the 1361 images of the four datasets.
authors.affiliation: INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal; FEUP - Faculdade de Engenharia, Universidade do Porto, Porto, Portugal. Electronic address: amendon@fe.up.pt.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Mendonça
authors.forename: António
authors.initials: A
authors.lastname: Sousa
authors.forename: Luís
authors.initials: L
authors.lastname: Mendonça
authors.forename: Aurélio
authors.initials: A
authors.lastname: Campilho
mesh_terms: D000465:Algorithms; D016208:Databases, Factual; D019277:Entropy; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D009898:Optic Disk / Q000098:blood supply*; D010363:Pattern Recognition, Automated / Q000379:methods*; D012171:Retinal Vessels
keywords: Entropy; Optic disc localization; Retinal image analysis; Retinal vessel segmentation