 The above relation which defines the essential matrix was published in 1981 by H. Christopher Longuet-Higgins, introducing the concept to the computer vision community.Richard Hartley and Andrew Zisserman's book reports that an analogous matrix appeared in photogrammetry long before that.Longuet-Higgins' paper includes an algorithm for estimating formula_2 from a set of corresponding normalized image coordinates as well as an algorithm for determining the relative position and orientation of the two cameras given that formula_2 is known.