The term is used in conjunction with security systems that identify people based on a previous recording of one or more of their body characteristics.
Live capture is used in some automatic teller machines (ATMs) to ensure that the person making the transaction is the individual to whom the magnetic ATM card belongs. One approach is iris scanning.
The subject must look in the general direction of a camera and the eyes must be uncovered. Otherwise, the transaction will not be completed. Another approach to live capture is facial recognition, which has been suggested as a way to scan crowds for suspected terrorists.
An advantage of live capture is that relevant action can be taken at the moment the data is gathered; for example, the police can be summoned if an intruder on a property is identified as a known criminal suspect by facial recognition equipment.
In contrast, so-called dead or passive capture is used primarily to gather evidence or make comparisons of samples when the subject is not physically present.
To attenuate is to taper gradually and attenuated refers to reducing the virulence (infectivity) of a pathogenic microorganism.