Method for remote photoplethysmography facilitating obtaining a first signal (42;50a-n;76) for analysis to characterize a periodic component thereof, the periodic component corresponding to a biological phenomenon in a living being, including: obtaining from a video camera three second signals (18-20;55-57) comprising a sequence of image frames including of pixel values representative of intensities of captured electromagnetic radiation, each corresponding to a respective different radiation frequency range, applying a transformation (22,26,30;59,63,67,71) to the second signals (18-20;55-57) to obtain an output signal (31;72) from which the first signal (42;50a-n;76) is derivable such that any value of the output signal (31;72) is based on values from each respective second signal (18-20;55-57) at corresponding points in time, wherein the transformation includes a linear combination of the logarithms of the second signals with at least one coefficient differing from zero, and (i) analyzing the second signals (18-20;55-57) and/or the output signal (31;72) and/or the first signal (42;50a-n;76) derived from the output signal (31;72) and using the analysis to select a value of a parameter determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied, said value being selected for a parameterized operation included in the transformation (22,26,30); and/or (ii) calculating a value of a time-varying factor determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied based on at least one second signal, and applying the factor in an operation (59,63) in at least one of a number of parallel sequences of operations comprising at least one such operation and taking a signal corresponding to a respective one of the second signals as input. obtaining from a video camera three second signals (18-20;55-57) comprising a sequence of image frames including of pixel values representative of intensities of captured electromagnetic radiation, each corresponding to a respective different radiation frequency range, applying a transformation (22,26,30;59,63,67,71) to the second signals (18-20;55-57) to obtain an output signal (31;72) from which the first signal (42;50a-n;76) is derivable such that any value of the output signal (31;72) is based on values from each respective second signal (18-20;55-57) at corresponding points in time, wherein the transformation includes a linear combination of the logarithms of the second signals with at least one coefficient differing from zero, and (i) analyzing the second signals (18-20;55-57) and/or the output signal (31;72) and/or the first signal (42;50a-n;76) derived from the output signal (31;72) and using the analysis to select a value of a parameter determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied, said value being selected for a parameterized operation included in the transformation (22,26,30); and/or (ii) calculating a value of a time-varying factor determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied based on at least one second signal, and applying the factor in an operation (59,63) in at least one of a number of parallel sequences of operations comprising at least one such operation and taking a signal corresponding to a respective one of the second signals as input. (i) analyzing the second signals (18-20;55-57) and/or the output signal (31;72) and/or the first signal (42;50a-n;76) derived from the output signal (31;72) and using the analysis to select a value of a parameter determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied, said value being selected for a parameterized operation included in the transformation (22,26,30); and/or (ii) calculating a value of a time-varying factor determining influences of components of respective second signals (18-20;55-57) on the output signal (31;72) when the second signals (18-20;55-57) are captured and the transformation (22,26,30;59,63,67,71) is applied based on at least one second signal, and applying the factor in an operation (59,63) in at least one of a number of parallel sequences of operations comprising at least one such operation and taking a signal corresponding to a respective one of the second signals as input.