Integrating ground and aerial views for urban site modeling

3D models of urban sites with good geometry and facade textures are needed for many planning and visualization applications. Approximate wireframe can be derived from aerial images but detailed textures must be obtained from ground level images. Integrating such views with the 3D models is difficult as only small parts of buildings may be visible in a single view. We describe a method that uses two or three vanishing points, not necessarily from orthogonal sets of parallel lines, and a small number of point correspondences to estimate the intrinsic and extrinsic parameters of the ground level cameras. Experimental results from some buildings are presented.