The design of two-dimensional gradient estimators based on one-dimensional operators

Two-dimensional (2-D) gradient estimators are some of the most useful tools in image processing. A computational procedure for the extension of one-dimensional (1-D) gradient estimators to two dimensions (2-D) is presented. The procedure is equivalent to the surface fitting method. It is, however, simpler in design, as the design is 1-D rather than 2-D. Higher order derivative estimators can also be constructed by the same procedure.