Patent ID: 8170293
Filing Date: 2012-05-01
Classification: G06K,G06T

Abstract:
1. A method for segmenting a biometric characteristic from an eye image captured by a biometric device, the method comprising the steps of: defining one or more first search windows in a captured eye image; identifying a first set of points corresponding to peaks in an image intensity gradient in each of the one or more first search windows; determining, from the first set of points, segments according to image intensity transitions, each segment having a center point; determining a position for the center point of each segment; grouping sets of the segments into a first set of clusters according to an analysis of the positions of the center points for the segments; and selecting, from the first set of clusters, a second set of clusters corresponding to a pupil image; fitting a first model template to the points for each set of segments corresponding to the second set of clusters, the fitted first model template corresponding to an initial pupil outer boundary for the pupil image; defining one or more second search windows in relation to the initial pupil outer boundary; identifying a second set of points corresponding to peaks in an image intensity gradient in each of the one or more second search windows; and fitting a second model template to the second set of points, the fitted second model template corresponding to a refined pupil outer boundary for the pupil image.