Fig. 6

Graph of the pulse measurement error \(\left| {L_{pulse}^{ } - L_{pulse}^{ reference} } \right|\) as a function of the camera operation frequency (number of frames per second) and the frequency of the measured pulse (L _pulse )—results of experiments. The graph was coloured with an artificial colour palette for better visualization. Red indicates large (about 3 heartbeats/min) values \(\left| {L_{pulse}^{ } - L_{pulse}^{ reference} } \right|\), and blue—values below 1 heartbeat/min respectively