In this paper we describe two general parametric, non symmetric 3×3 gradient models. Equations for calculating the coefficients of matrices of gradients are presented. These models for generating gradients in x-direction include the known gradient operators and new operators that can be used in graphics, computer vision, robotics, imaging systems and visual surveillance applications, object enhancement, edge detection and classification. The presented approach can be easier extended for large windows.
Artyom Grigoryan, Sos Agaian, "Two General Models for Gradient Operators in Imaging" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Image Processing: Algorithms and Systems XVI, 2018, pp 391-1 - 391-8, https://doi.org/10.2352/ISSN.2470-1173.2018.13.IPAS-391