Definitions for "Low-Pass Filter"
A signal filter which would be installed in a customer premises ADSL modem (ATU-R), which would not modify the low frequencies present in its input signal (the POTS transmission is sent unmodified to a phone), but does prevent the high frequency components (data) from reaching a customer's telephone. See High-Pass Filter.
A circuit designed to pass signals of low frequency while attenuating those of higher frequency.
A spatial-frequency filter which suppresses the high-frequency contrast variations in an image, and enhances the broad variations.