Stereoscopy, stereoscopic imaging or 3-D (three-dimensional) imaging is any technique capable of recording three-dimensional visual information or creating the illusion of depth in an image. The illusion of depth in a photograph, movie, or other two-dimensional image is created by presenting a slightly different image to each eye. Many 3D displays use this method to convey images. It was first invented by Sir Charles Wheatstone in 1840.[1] Stereoscopy is used in photogrammetry and also for entertainment through the production of stereograms. Stereoscopy is useful in viewing images rendered from large multi-dimensional data sets such as are produced by experimental data. Modern industrial three dimensional photography may use 3D scanners to detect and record 3 dimensional information. [2] The three-dimensional depth information can be reconstructed from two images using a computer by corresponding the pixels in the left and right images. Solving the Correspondence problem in the field of Computer Vision aims to create meaningful depth information from two images.   «   Summary from Wikipedia