1. A method, comprising: performing, by one or more computing devices: generating, by a panoramic image stitching module, a panoramic image from a set of input images according to a projection model by; projecting the input images onto a virtual sphere; and projecting the surface of the sphere onto a plane; passing, by the panoramic image stitching module to a post-processing module, one or more parameters of the projection model, including a virtual focal length for the virtual sphere onto which the input images are projected and an indication of a point at which the plane contacts the sphere, as metadata for the panoramic image; and applying, by the post-processing module, one or more image processing techniques, including a conversion of an original projection model for an image into an adaptive projection, to the panoramic image according to at least the virtual focal length and the indication of the point at which the plane contacts the sphere.