Standard approaches to the computation of stereo correspondence have difficulty when scene structure does not lie in or near the frontal-parallel plane, in part because an orientation disparity as well as a positional disparity is introduced. We propose a correspondence algorithm based on differential and projective geometry. Based on curves, the algorithm relates the (2D Frenet) differential structures (position, tangent, and curvature) in the left and right images with the Frenet geometry of the (3D) space curve.