where are profile images saved

os x version 10.4.11

as far as i know the only way to capture an image from my logitech cam is through system preferences (then) system accounts (picture edit )then take a video snapshot

if there is another way i'd appreciate the advice ,but if not

where and what type of file is the profile pic saves as

i can't find the image after i take it other than it becoming my new profile picture

thanks