The present invention relates to a device and a method for extracting information from detected characteristic signals. A data stream (26) derivable from electromagnetic radiation (14) emitted or reflected by an object (12) is received. The data stream (26) comprises a continuous or discrete time-based characteristic signal ( ; 98) comprising at least two main components (92a, 92b, 92c) related to respective complementary channels (90a, 90b, 90c) of a signal space (88). The characteristic signal ( ; 98) is mapped to a defined component representation ( , , , ; , ) under consideration of a substantially linear algebraic signal composition model so as to specify a linear algebraic equation. The linear algebraic equation is at least partially solved under consideration of an at least approximate estimation of specified signal portions ( , , ). Consequently, an expression highly indicative of the at least one at least partially periodic vital signal (20) can be derived from the linear algebraic equation.