Nanoporous membranes are an important class of nanomaterial that can be used in many applications, especially in micro- and nanofiltration. Electrospun nanofibrous membranes have gained increasing attention due to the high porosity, large surface area per mass ratio along with small pore sizes, flexibility, and fine fiber diameter, and their production and application in development of filter media. Image analysis is a direct and accurate technique that can be used for structural characterization of porous media. This technique, due to its convenience in detecting individual pores in a porous media, has some advantages for pore measurement. The threedimensional (3D) reconstruction of porous media, from the information obtained from a two-dimensional (2D) analysis of photomicrographs, is a relatively new research area. This chapter provides a detailed review on relevant approach of 3D reconstruction from two views of single 2D image. The review concisely demonstrated that 3D reconstruction consists of three steps which is equivalent to the estimation of a specific geometry 188group. The method’s algorithm has five major steps: (1) take a set of SEM images of a sample, (2) identify key points in the images that can possibly be detected in other images in the set, (3) search for corresponding points in images, (4) finding the fundamental matrix and computing 3D coordinates, and (5) triangulating the 3D points to compute 3D surface model. The obtained properties such as roughness, thickness, and porosity using proposed methods have been compared with the results of direct measurement. The evidence showed that the proposed method will be useful for extraction of volume information, such as porosity and thickness of nano-fibrous structures with high precision and accuracy.