title: Approximate nearest neighbour field based optic disk detection.
abstract: Approximate Nearest Neighbour Field maps are commonly used by computer vision and graphics community to deal with problems like image completion, retargetting, denoising, etc. In this paper, we extend the scope of usage of ANNF maps to medical image analysis, more specifically to optic disk detection in retinal images. In the analysis of retinal images, optic disk detection plays an important role since it simplifies the segmentation of optic disk and other retinal structures. The proposed approach uses FeatureMatch, an ANNF algorithm, to find the correspondence between a chosen optic disk reference image and any given query image. This correspondence provides a distribution of patches in the query image that are closest to patches in the reference image. The likelihood map obtained from the distribution of patches in query image is used for optic disk detection. The proposed approach is evaluated on five publicly available DIARETDB0, DIARETDB1, DRIVE, STARE and MESSIDOR databases, with total of 1540 images. We show, experimentally, that our proposed approach achieves an average detection accuracy of 99% and an average computation time of 0.2 s per image.
authors.affiliation: Video Analytics Lab, Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore 560 012, India. Electronic address: avinashrs@ssl.serc.iisc.in.
authors.forename: S Avinash
authors.initials: SA
authors.lastname: Ramakanth
authors.affiliation: Video Analytics Lab, Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore 560 012, India. Electronic address: venky@serc.iisc.in.
authors.forename: R Venkatesh
authors.initials: RV
authors.lastname: Babu
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009898:Optic Disk / Q000033:anatomy & histology*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D042262:Retinoscopy / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: Approximate Nearest Neighbour Field; FeatureMatch; Fundus or retinal image processing; Optic disk detection