There is a approach that uses notions from Discrete Geometry: Discrete Geometry is a discipline that works with objects defined as sets of pixels that try to mimic their standard counterparts. It defines discrete segments, discrete circles, discrete planes etc... In your case, there is an algorithm  that has a definition of what a discrete segment is, and that reconstructs in the input image the set of maximal segments, i.e. segments that cannot be further extended by adding new pixels to them. See also the extensions to fuzzy data [2,3]. The approach was successfully applied to 3D reconstruction from multiview images 
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