VAMPIRE: Vessel Assessment and Measurement Platform for Images of the REtina A Perez-Rovira, T MacGillivray, E Trucco, K S Chin, K Zutis, C Lupascu, D Tegolo, A Giachetti, PJ Wilson, A Doney, and B Dhillon Abstract—We present VAMPIRE, a software application for efficient, semi-automatic quantification of retinal vessel properties with large collections of fundus camera images. VAMPIRE is also an international collaborative project of four image processing groups and five clinical centres. The system provides automatic detection of retinal landmarks (optic disc, vasculature), and quantifies key parameters used frequently in investigative studies: vessel width, vessel branching coefficients, and tortuosity. The ultimate vision is to make VAMPIRE available as a public tool, to support quantification and analysis of large collections of fundus camera images. I. I NTRODUCTION VAMPIRE is an easy-to-use tool allowing efficient quan- tification of features of the retinal vasculature with hundreds or thousands of images. Most processing is performed auto- matically before user intervention, which is kept at a mini- mum. The VAMPIRE interface provides easy-to-understand visual feedback of the features extracted and a set of tools that allows the user to easily identify, locate and correct wrong measurements. No experience of image processing algorithms is assumed. Retinal microvascular abnormalities seen on fundal pho- tography are associated with diabetes, hypertension, stroke and cognitive impairment [1], [2], [3]. Often, diagnostic fo- cus is placed on structural features of the vasculature such as vessel width, branching angles, and vessel tortuosity [4], [5], [6]. Retinal blood vessels have similar size and physiology to cerebral small vessels and may act as a surrogate marker for them. Abnormalities are often subtle and may be missed by visual observation or conventional retinal image inspection. Taking manual measurements in retinal fundus images is also time-consuming and laborious, slowing down significantly the analysis of large numbers of images. Hence the need for software tools that can process large numbers of images in an objective, effective and efficient manner. Some systems have appeared recently for semi-automatic assessment of retinal vessels. They include RISA, ROPtool, and ROPnet, designed within the context of retinopathy of Perez Rovira, Trucco, Chin and Zutis are with the School of Computing, Univ of Dundee, UK e.trucco@dundee.ac.uk MacGillivray is with the Clinical Research Imaging Centre, Univ of Edinburgh, UK T.J.MacGillivray@ed.ac.uk Lupascu and Tegolo are with the Dept of Mathematics and Informatics, Univ of Palermo, Italy lupascu,tegolo@math.unipa.it Giachetti is with the Dept of Computer Science, Univ of Verona, Italy andrea.giachetti@univr.it Wilson and Doney are with Ninewells Hospital, NHS Tayside, UK pj.wilson@nhs.net, a.doney@cpse.dundee.ac.uk Dhillon is with the Princess Alexandra Eye Pavilion, NHS Lothian, UK Bal.Dhillon@luht.scot.nhs.uk Fig. 1. Examples of OD location with ORIGA-light image (top; courtesy of Dr Liu Jiang, A-STAR Singapore) and Dundee diabetic screening image. prematurity, and IDx, IVAN, CAIAR, SiVA and AVRnet in wider contexts. Space constraints preclude a comparative discussion. Apart from IDx, obtainable for research only, no system appears to be accessible publicly yet. 1 VAMPIRE starts with a segmentation of blood vessels and optic disc, followed by geometry estimation at vessel bifurcations, the tortuosity of major vessels, and fractal dimension of the vasculature. Most of the processing is hidden from the user, who is expected to provide only a minimal level of inter- vention after all measures are calculated. The current, beta version of VAMPIRE includes modules for vessel detection, branching angle measurements, vessel width estimation and tortuosity estimation. Optic disc location and fractal analysis are available and to be incorporated. II. VAMPIRE OVERVIEW A. User interface VAMPIRE allows the user to load a set of images of arbitrary size. At the moment, no automatic quality as- sessment [7] is included. VAMPIRE locates the vasculature network and estimates branching coefficients, vessel widths, and tortuosity. The user can revise results efficiently, making corrections or discarding images. All measures, together with