New to R and SomaticSignatures package.

I want to compare a mutational signature that I derived using SomaticSignatures package to SBS signatures published at the COSMIC site. Do I have to normalize the derived signature for background distribution of sequence motifs (trinucleotide distribution) in the reference genome? I understand that all COSMIC SBS signatures are adjusted for the trinucleotide distribution in the reference. From the vignette provided with the package and the examples therein it is not unambiguously clear whether the mutational spectra and the mutational signatures are normalized or not for the distribution of trinucleotides in the reference genome.

What would be the easiest way to apply such normalization if it is needed? Perhaps there is an appropriate package for such purpose?

Thanks.