A spam fax filter which has been configured in accordance with the present
invention can include a fax transformation processor configured to
transform rasterized fax images into non-rasterized representations of
fax images. The spam fax filter further can include a knowledge base of
known spam characteristics. Finally, the spam fax filter can include a
comparator configured to compare non-rasterized representations of fax
images produced by the fax transformation processor to the
characteristics in the knowledge base to detect spam fax in the spam fax
filter.