Authors:
Sandra Morales
1
;
Álvar-Ginés Legaz-Aparicio
2
;
Valery Naranjo
1
and
Rafael Verdú-Monedero
2
Affiliations:
1
Universitat Politècnica de València and Unidad Conjunta UPV- FISABIO, Spain
;
2
Universidad Politécnica de Cartagena, Spain
Keyword(s):
Retinal Image, Bifurcation Angle, Multiple Orientation Estimation, Regularized Morphological Opening.
Related
Ontology
Subjects/Areas/Topics:
Applications and Services
;
Biomedical Engineering
;
Biomedical Signal Processing
;
Computer Vision, Visualization and Computer Graphics
;
Medical Image Detection, Acquisition, Analysis and Processing
Abstract:
This paper describes a new approach to compute bifurcation angles in retinal images. This approach is based on the estimation of multiple orientations at each pixel of a gray retinal image. The main orientations are provided by directional openings whose outputs are regularized in order to extend the orientation information to the whole image. The detection of vessel bifurcations is based on the coexistence of two or more than two different main orientations at the same pixel. Once the bifurcations and crossovers has been identified, bifurcation angles are calculated. The proposed procedure of computing bifurcation angles by means of orientation estimation at all pixels of the gray level image is much more stable than those methods which are based on the skeleton of the vascular tree, since a slight variation of a pixel of the skeleton can produce a significant change in the angle value.