Characteristic curves representative of ridges or edges in an image can be generated from a gradient magnitude image and gradient vector data associated with the image. Such characteristic curves may be evaluated with filter criteria in order to identify whether a characteristic curve or curves is indicative of a feature in the image. Filter criteria can be determined to identify a desired feature in the image, whereby the filter criteria evaluates a characteristic curve or curves, or points in a characteristic curve or curves in order to identify features in the image. Identified features can be graphically indicated on the display of a computing device.
