REVIEW database comparison.

REVIEW database comparison of successful measurement percentages (i.e. the percentage of vessel locations at which a meaningful measure of vessel diameter was returned by the algorithm), mean vessel diameters and standard deviations of the measurement error (). The data included in the top part of the table are reproduced from [26] (© 2009 IEEE), to which we have added the results of the graph-based algorithm [34] and those obtained by applying the same tests using our algorithm. O1–O3 were obtained from measurements made by three manual observers, and ‘Standard’ is the average of these measurements.