A method, apparatus and computer program product train a signature encoding module and a query processing module. In a method, at least one of the signature encoding module and the query processing module is trained by providing the signature encoding module with a reference image containing a particular object of interest that is marked therewithin. The method generates a digital signature of the object of interest and at least some context associated therewith and provides the query processing module with a query image and the digital signature representing the object of interest and at least some of the context associated therewith. The method additionally identifies the object of interest within the query image based upon the digital signature and modifies at least one of the signature encoding module or the query processing module based upon a qualitative or quantitative difference between the objects of interest identified within the query image and marked in the reference image.