1. A computer implemented method of computing a features dataset classifying a pose of a hand of a human, comprising: selecting, using a computerized processor, a global orientation category (GOC) defining a spatial orientation of a hand of a human in a three dimensional (3D) space by applying a plurality of GOC classifying functions on a received image segment depicting said hand; identifying an in-plane rotation by applying a plurality of in-plane rotation classifying functions on said image segment, said plurality of in-plane rotation classifying functions being selected according to said GOC; aligning said image segment in a 2 dimensional (2D) plane according to said identified in-plane rotation; applying a plurality of hand feature classifying functions on said aligned image segment, each one of said plurality of feature classifying functions outputting a current discrete pose value of an associated one of a plurality of hand pose features; and outputting a features dataset defining a respective said current discrete pose value for each of said plurality of hand pose features for classifying a current hand pose of said hand; wherein said GOC is identified after estimating a center of hand by applying a plurality of center of hand classifying functions on said image segment.