Homography estimation from multithreshold edges of a feature

摘要

A method of analysing a captured image, comprising the steps of capturing a digital image comprising an instance of a target object for each of a plurality of different brightness threshold levels, generating contours from the captured digital image that indicate where in the captured digital image the pixel values of the captured digital image cross the respective brightness threshold level identifying instances of a contour corresponding to a characteristic feature of said target object for at least two of the respective brightness threshold levels and estimating a homography of the characteristic feature of the target object of the captured image based upon the two or more instances of its corresponding contour.