Main processing blocks of getsources and getfilaments. For a complete extraction, both methods require two runs (left): the initial and final extractions (red blocks; the preparation and flattening steps are shown in blue; cf. Paper I). A more detailed presentation of the processing steps (right) shows that both algorithms would have had lots of identical actions, if conceived and coded separately. The getfilaments algorithm is essentially localized in only the cleaning and combining steps of getsources (highlighted in yellow). In practice, getfilaments is an integral part of the source extraction code, activated by a single configuration parameter of getsources.