1. A device configured to obtain a vital sign of a subject, comprising an interface configured to receive a set of image frames of a subject, an image frame including a plurality of image pixels having associated pixel values; at least one processor programmed to: extract a photoplethysmographic, PPG, signal of the subject from said set of image frames; determine a feature of said PPG signal indicative of the quality of the information content of the extracted PPG signal with respect to a desired vital sign of the subject; determine a binning configuration based on the determined feature of the extracted PPG signal and based on a lookup table including a number of binning configurations for different values of the determined feature of the extracted PPG signal or a continuous or discrete function thereof, said binning configuration being provided for controlling binning of image pixels of an image frame bin image pixels of an image frame based on the determined binning configuration to obtain a binned image frame, wherein the PPG signal is extracted from said binned image frames; and determine vital sign information from the extracted PPG signal.