1. A method comprising: determining randomly distributed features in an object; determining a probability density function associated with the object; compressing data representing the randomly distributed features, wherein the compressing is based in part on the probability density function; encoding the compressed data with a signature; and creating a label comprising the object and the encoded data; determining vectors associated with the randomly distributed features based, at least in part, on the probability density function; and encoding the vectors using an arithmetic coding algorithm, wherein the algorithm comprises: set U as a list of all unit areas in S−S i −u list of all marked units, M(u), is set to M(u)=Ø do find all unit areas V=argmin ν⊂U ∥Q ν −Q u ∥ do find unit area w=argmax νεV ζ(1, ν) set AC range for w to γ(w,u) set of nodes ordered before w is M w (u)=M(u) M(u)=M(u)∪w, V=V−w, U=U−w while V≠Ø while U≠Ø.