The present invention relates to an apparatus (10) for determining vital sign information (R) from a subject (12), comprising a detection unit (22) for detecting radiation (24) from a field of view (42) and for determining characteristic parameter (S) including vital sign information (R) of the subject (12) from different areas (48) of the field of view (42), a frequency analysis unit (30) for determining a spectral parameter of the characteristic parameter (S) derived from the different areas (48), a selection unit (32) for selecting at least one of the areas (48) of the field of view (42) on the basis of the spectral parameter, and a calculation unit (34) for calculating the vital sign information (R) on the basis of the characteristic parameter (S) from the at least one selected area (48).
