We present a novel method that determines whether a macula centered retinal image is from the left or right eye and automatically detects the optic disc, the fovea and the vascular arch by inferring the location of a set of landmarks placed on these structures. The algorithm relies on a specific energy function that combines global and local cues. The global cues are derived from vascular atlases of the vessel orientation and thickness on the retina as well as a vascular distance map. A fourth component models the local appearance around each of the landmarks in the model and is able to estimate the distance between a position in the image and the target position of a landmark. For the minimization of the energy function a combination of optimization methods is used. We compare the results of several different system setups and combinations of energy function components with the performance of a second human observer. The best performing system localizes the OD in 91% of all cases, the fovea in 94% of all cases and correctly positions 74% of all vessel landmarks. The results show that a combination of global and local energy function components is required to obtain optimal results.
Automatic Detection of the Optic Disc, Fovea and Vascular Arch in Digital Color Photographs of the Retina
M. Niemeijer, B. van Ginneken, F. ter Haar and M. Abràmoff
Proceedings of the British Machine Vision Conference 2005:109-118.