7. The method of claim 5 , wherein the comparison score can be described according to 
 κ on ( x,x ij )=λ· l i ( x )+(1−λ)· s ( x,x ij ), where x is the lower-dimensional representation of the query image, where κ on (x,x ij ) is the comparison score, where s(x,x ij ) is a matching score between the lower-dimensional representation of the query image x and the lower-dimensional representation of the reference image x ij , where l i (x) is a classifier output, and where λ is a weighting parameter.
8. The method of claim 7 , wherein the matching score is a cosine distance, where s(x,x ij )=x ij T x, and where the lower-dimensional representation of the the query image x and the lower-demensional representation of the reference image x ij have been pre-normalized by L 2 -normalization.