Integrating stereo and photometric stereo to monitor the development of glaucoma

摘要

Progress on a system to monitor the development of glaucoma by measuring the topography of the optic disk is reported. The need for an accurate method for doing this using passive vision is explained. Sparse depth measurements from stereo matching of blood vessels provide insufficient constraint for reconstructing the surface of the optic disk. Shape from shading has to contend with a spatially-varying albedo. We show how a particular arrangement of fundus cameras allows us to apply a technique akin to homomorphic filtering to recover estimates of δzδx that can be smoothed by appropriate regularization. Stereo is integrated with these photometric stereo depth estimates. Examples of artificial object and optic disk surface reconstructions are presented.