Make filter2d example self-contained.
Make filter2d example self-contained.

sklam/numba,cpcloud/numba,cpcloud/numba,pitrou/numba,jriehl/numba,ssarangi/numba,stefanseefeld/numba,pitrou/numba,cpcloud/numba,pitrou/numba,numba/numba,gdementen/numba,sklam/numba,stonebig/numba,gdementen/numba,jriehl/numba,seibert/numba,seibert/numba,sklam/numba,IntelLabs/numba,sklam/numba,ssarangi/numba,gmarkall/numba,ssarangi/numba,stuartarchibald/numba,shiquanwang/numba,gmarkall/numba,IntelLabs/numba,gmarkall/numba,IntelLabs/numba,pombredanne/numba,jriehl/numba,numba/numba,pitrou/numba,pitrou/numba,jriehl/numba,stuartarchibald/numba,seibert/numba,shiquanwang/numba,stonebig/numba,gmarkall/numba,cpcloud/numba,pombredanne/numba,stefanseefeld/numba,stuartarchibald/numba,GaZ3ll3/numba,stuartarchibald/numba,gmarkall/numba,stuartarchibald/numba,stonebig/numba,pombredanne/numba,stefanseefeld/numba,stefanseefeld/numba,jriehl/numba,numba/numba,gdementen/numba,GaZ3ll3/numba,gdementen/numba,numba/numba,GaZ3ll3/numba,stefanseefeld/numba,shiquanwang/numba,GaZ3ll3/numba,numba/numba,stonebig/numba,stonebig/numba,cpcloud/numba,GaZ3ll3/numba,ssarangi/numba,pombredanne/numba,sklam/numba,ssarangi/numba,pombredanne/numba,IntelLabs/numba,seibert/numba,IntelLabs/numba,gdementen/numba,seibert/numba