From Longman Dictionary of Contemporary Englishfilter something ↔ out phrasal verb1 SEPARATEto remove something, using a filter The pump filters out mud.2 to remove words, information etc that you do not need or want Net users can filter out unwanted emails with software. → filter→ See Verb table
Examples from the Corpus
filter out• Once convinced it is easy to filter them out.• They have variable suction for cleaning delicate curtains, as well as thick carpet, and filters that take out allergens as well as dust.• Each spectacle lens then filters one image out, based on its color or polarity.• Don't filter them out because they seem silly, and don't be afraid of being wrong.• The overflow connection should have a filter to keep out insects and an internal dip tube to prevent icy draughts. 