Hu's moment invariants: how invariant are they under skew and perspective transformations?
R. Sivaramakrishna, N.S. Shashidharf · 2002
Hu's (1962) moment invariants are used in pattern recognition to provide a scale, orientation and position invariant characterization of the shape of a given object. In practical situations, objects may undergo other types of deformations, most commonly skew and perspective distortions. This paper explores the behaviour of Hu's invariants under these distortions.