1. A method for obtaining a descriptor that is invariant to arbitrary axial symmetries from a visual patch around a detected point of interest of an image, the method comprising: extracting, by a computer, a visual patch around a detected point of interest of said image; obtaining an orientation direction of the point of interest; computing a polarity of the point of interest which defines the location of a scanning path starting point from the orientation direction; if the computed polarity does not conform to a predefined polarity, mirroring the extracted visual patch with respect to the orientation direction; and, extracting said descriptor that is invariant to arbitrary axial symmetries by scanning the visual patch according to the scanning path, thereby allowing retrieving or indexing an image in an image retrieving or indexing method.