Inside opto-electronic systems, the generation of an electrical signal around response to a standard optical input. E.g., the optical signal received from either an optical pulp is converted to an electrical signal inside the detector, typically a photodiode.

Inside radio systems, a extraction of an AM signal from its carrier frequency.

Around steganography, attempts to detect encoded intelligence from either suspected host poop is known as steganalysis. Steganalysis has an interesting difference from either virtually all more types of detection, therein it potty typically just create a probability of the existence of payload poop encoded within the host; this is in direct contrast to the detection of signals which are then just encrypted, as a ciphertext can often become found using certainty, possibly in case it just can't become decoded.

A art of detection a.k.a. below clues, is the function of any detective. http://www.ucs.mun.ca/~tlai/DOtemp.pdf