Unobtrusive remote monitoring device for extracting physiological information that is representative of at least one at least partially periodic vital signal from detected characteristic signals, the device comprising: - an interface arranged for receiving a data stream that comprises a sequence of image frames derivable from electromagnetic radiation emitted or reflected by an object , the data stream comprising a continuous or discrete characteristic signal including physiological information that is indicative of desired object motion, - an extractor means arranged for extracting the physiological information from the data stream by deriving a sequence of characteristic index elements from the sequence of image frames through a dimensional reduction applied to the image frames , the plurality of characteristic index elements comprising a directional motion component that is associated with a disturbance-reduced index element that has a determined orientation substantially aligned with a reference motion direction and that describes a preferential direction of object motion indicative of the at least one at least partially periodic vital signal , such that the sequence of characteristic index elements is indicative of a derivative signal form comprising the physiological information , wherein the dimensional reduction comprises agglomerating and projecting data stream properties associated with respective pixel sub-entities of the image frames comprised in the data stream onto the disturbance-reduced index element , thereby obtaining the respective characteristic index element , such that motion information indicative of the desired signal to be extracted is still contained in the resulting characteristic index elements , and - an analyzing means arranged for determining a temporal variation of the derivative signal form , wherein the temporal variation corresponds to the at least one at least partially periodic vital signal . - an interface arranged for receiving a data stream that comprises a sequence of image frames derivable from electromagnetic radiation emitted or reflected by an object , the data stream comprising a continuous or discrete characteristic signal including physiological information that is indicative of desired object motion, - an extractor means arranged for extracting the physiological information from the data stream by deriving a sequence of characteristic index elements from the sequence of image frames through a dimensional reduction applied to the image frames , the plurality of characteristic index elements comprising a directional motion component that is associated with a disturbance-reduced index element that has a determined orientation substantially aligned with a reference motion direction and that describes a preferential direction of object motion indicative of the at least one at least partially periodic vital signal , such that the sequence of characteristic index elements is indicative of a derivative signal form comprising the physiological information , wherein the dimensional reduction comprises agglomerating and projecting data stream properties associated with respective pixel sub-entities of the image frames comprised in the data stream onto the disturbance-reduced index element , thereby obtaining the respective characteristic index element , such that motion information indicative of the desired signal to be extracted is still contained in the resulting characteristic index elements , and - an analyzing means arranged for determining a temporal variation of the derivative signal form , wherein the temporal variation corresponds to the at least one at least partially periodic vital signal . <EOS>