The Concept of Stereo Vision arises from the Perception or Estimation of Depth by using two different Planar (i.e. zero Depth) images. For Example, in humans, objects at different distances from the persons eyes are projected as images in the two retinae which are at a separation 'd' in their position Co-ordinates, giving a clue to the horizontal disparity, also referred to as the retinal disparity, which forms the basis for the humans' perception of depth even though retinal images are planar.

The Chief Objective of Computer stereo vision, a branch of the various sciences of computer vision is to generate a quantitative measure of the depth through the use of 2 Cameras.

The cameras take pictures of identical points, but they are separated by a ceratin amount, something like human eyes. A computational algorithm processes the images while super imposing them on top of each other to find the regions (R.O.I) that match. The displacement is called the disparity. The value of disparity at which objects in the image give the best matching results is used by the algorithm to get a depth estimate.