The present invention relates to a device (12) for obtaining a vital sign of a subject (14), comprising an interface (22) for receiving a set of image frames (24) of a subject (14), a signal extraction unit (26) for extracting a photoplethysmographic (PPG) signal of the subject (14) from said set of image frames (24), a signal evaluation unit (28) for determining a feature of said PPG signal indicative of the information content of the extracted PPG signal with respect to a desired vital sign of the subject (14), a processing unit (30) for determining a binning configuration based on the determined feature of the extracted PPG signal, said binning configuration being provided for controlling binning of image pixels of an image frame and a vital signs determination unit (32) for determining vital sign information from the extracted PPG signal.
