An ellipsoid-based perspective projection correction for wide-angle images

Wide-angle images have been wisely used in many areas since they can provide much larger field-of-view (FOV) of a scene. But distortions in these images disturb users' perception and many research works have been investigated to tackle this problem. Up to now, several correction methods have been developed, such as the perspective, Mercator and stereographic projections. However, these methods tend to bend straight lines or distort the shapes of objects, and [Zorin and Barr 1995] pointed out that no global projection can preserve both straight lines and the shapes of objects. Recently, [Carroll et al. 2009] proposed a content-preserving approach to map wide-angle photographs onto image plane by computing a spatially-varying projection. Unfortunately, it required the users to draw about 20 lines on average as an initial step.