EYE FEATURE IDENTIFICATION

An image of an eye is obtained via a camera. A multi-step filter is applied to the image for multiple iterations. Applying the multi-step filter includes, for each iteration, performing one or more pixel merge operations on the image. The pixel merge operations are controlled based on one or more input parameters to control whether or not the iteration classifies pixels of the image as corresponding to a feature of the eye. The one or more input parameters vary from at least one iteration to another. The iterations each output a provisional output, in which some pixels of the image are deemed as corresponding to the feature of the eye. The provisional outputs provide diverse definitions of the eye feature, and may be combined in various ways to yield a refined output, in which some pixels of the image are deemed as corresponding to the feature of the eye.