1. A method for detecting cardiac arrhythmia from signals generated from video images captured of a subject of interest being monitored for cardiac function in a non-contact remote sensing environment, the method comprising: receiving a time-series signal generated from video images captured of a region of exposed skin where a photoplethysmographic (PPG) signal of a subject of interest can be registered, said video comprising video images captured by at least one imaging channel capturing PPG signals; performing signal separation on said time-series signal to extract a PPG signal for said subject; detecting peak-to-peak pulse points in said PPG signal; analyzing said pulse points to obtain peak-to-peak pulse dynamics; and determining whether a cardiac arrhythmia exists based on said pulse dynamics.