1 ) A method for obtaining a descriptor that is invariant to arbitrary axial symmetries from a visual patch (PAi, nPAi) around a detected point of interest (pi) of an image (I), said descriptor being extracted by scanning the visual patch (PAi, nPAi) according to a scanning path (SPi), characterized in that the method obtains an orientation direction (ODi) of the point of interest (pi), computes a polarity (Poi) of the point of interest which defines the location of the scanning path starting point (sSPi) from the orientation direction (ODi), and if the computed polarity (Poi) does not conform to a predefined polarity (pPoi), mirrors the extracted visual patch (PAi, nPAi) with respect to the orientation direction (ODi).