1. A method of detecting features-of interest in an image, comprising: using a processor to perform steps of: processing the image to make an intensity independent representation of an image intensity profile; comparing the intensity independent representation with an intensity independent shape model for predefined features of interest by: convolving the intensity independent representation with a quadrature filter to derive the phase and amplitude of a pair of odd and even components of the profile in the spatial or spatio temporal frequency domains; deriving from a difference between the components a measure of one of the feature symmetry or asymmetry along the profile, deriving from the components a measure of the local amplitude along the profile; and defining areas of the image satisfying a predefined constraint on the value of said one of the feature symmetry or asymmetry as satisfying the shape model and thus belonging to an image feature; and storing for the profile a label comprising said measures.