A surveillance camera system comprising: a thermal imager (1202, 1502) comprising a focal plane array configured to capture thermal images of a scene; a light source configured to illuminate the scene, wherein the light source is configured to illuminate the scene by visible and/or near infrared light; a camera (1204, 1220, 1504) configured to capture additional images of the scene, wherein the camera is a non-thermal camera; and a processor (195, 1210, 1510) configured to: detect a candidate object in the scene based on the thermal images, in response to detecting the candidate object, determine whether the candidate object corresponds to an object of interest or a spurious object, not of interest for surveillance purposes, by analyzing temperature data contained in pixels of the thermal images to determine geometric properties and thermal characteristics of the candidate object, and in response to determining that the candidate object corresponds to the object of interest, selectively operate the light source for illuminating the scene and the camera (1204,1220,1504) for capturing images of the scene according to a defined association between the object of interest and corresponding operations for the light source and the camera, wherein if only a spurious object is detected, no light source is turned on. a thermal imager (1202, 1502) comprising a focal plane array configured to capture thermal images of a scene; a light source configured to illuminate the scene, wherein the light source is configured to illuminate the scene by visible and/or near infrared light; a camera (1204, 1220, 1504) configured to capture additional images of the scene, wherein the camera is a non-thermal camera; and a processor (195, 1210, 1510) configured to: detect a candidate object in the scene based on the thermal images, in response to detecting the candidate object, determine whether the candidate object corresponds to an object of interest or a spurious object, not of interest for surveillance purposes, by analyzing temperature data contained in pixels of the thermal images to determine geometric properties and thermal characteristics of the candidate object, and in response to determining that the candidate object corresponds to the object of interest, selectively operate the light source for illuminating the scene and the camera (1204,1220,1504) for capturing images of the scene according to a defined association between the object of interest and corresponding operations for the light source and the camera, wherein if only a spurious object is detected, no light source is turned on. detect a candidate object in the scene based on the thermal images, in response to detecting the candidate object, determine whether the candidate object corresponds to an object of interest or a spurious object, not of interest for surveillance purposes, by analyzing temperature data contained in pixels of the thermal images to determine geometric properties and thermal characteristics of the candidate object, and in response to determining that the candidate object corresponds to the object of interest, selectively operate the light source for illuminating the scene and the camera (1204,1220,1504) for capturing images of the scene according to a defined association between the object of interest and corresponding operations for the light source and the camera, wherein if only a spurious object is detected, no light source is turned on.