Patent ID: 8275204
Filing Date: 2012-09-25
Classification: G06K,G06T

Abstract:
1. A method for estimating the joint radiometric and geometric deformations of an image of an object using a radiometry-first approach comprising: (a) analyzing a first observation h of an image, about a known m-dimensional signal g, of the form where Q is a non-linear mapping of the intensities (radiometry), A is an affine (geometric) transformation, and η is an additive noise; (b) estimating the joint radiometric and geometric deformations of the first observation without limitations on the magnitude of the geometric or radiometric deformations; and (c) analyzing the deformations of the first observation in comparison to a second observation of an object to determine whether the first observation and the second observation are of the same object; wherein (i) the sample distribution transformation T is invariant under right-hand affine compositions: T(g∘A)=Tg, and T(W∘g)=[Tg]∘W (ii) applying T to the (noiseless) relation h=Q∘g∘A, to obtain Th=[Tg]∘Q (iii) using the transformation T to convert a functional relation expressed by a left-hand composition (“radiometric deformation”) into a new functional relation expressed by a right-hand composition (“geometric deformation”) so equation H(t)=[G∘Q (iv) producing linear constraints on Q, enabling the explicit recovery of Q (v) once the radiometric deformation Q (or equivalently its inverse Q and (vi) reducing the problem to a strictly geometric problem where A is recovered.