Detection of retinal vascular bifurcations by rotation-, scale- and reflection-invariant COSFIRE filters

We propose trainable filters, which we call COSFIRE (Combination Of Shifted FIlter REsponses), and use to de- tect vascular bifurcations in retinal images. We configure a COSFIRE filter to be selective for a bifurcation that is speci- fied by a user in a single-step training phase. The automatic configuration comprises the selection of channels of a bank of Gabor filters and the determination of certain blur and shift parameters. A COSFIRE filter response is computed as the geometric mean of the blurred and shifted responses of the selected Gabor filters. The proposed filters share sim- ilar properties with some shape-selective neurons in visual cortex. With only five filters we achieve a recall of 98.57% at a precision of 95.37% on the 40 binary retinal images (from DRIVE), containing more than 5000 bifurcations.peer-reviewe

Costing mixed coxian phase-type systems in a given time interval

Previously we have introduced a modelling framework to classify individuals in Mixed Coxian Phase-type Systems. We here add costs and obtain results for moments of total costs in (0, t], for an individual, and a cohort arriving at time zero. Based on data from the Belfast City Hospital Stroke Unit we use the overall modelling framework to obtain results for total cost in a given time interval to facilitate planners who have limited time horizons for budget planning.peer-reviewe