An imaging method, comprising: obtaining a plurality of infrared images forming an infrared video captured via an infrared camera; obtaining a plurality of visible light images forming a visible light video captured via a visible light camera, each visible light image of the plurality of visible light images being time-registered and spatially-registered with each infrared image of the plurality of infrared images; applying facial recognition to each infrared image of the plurality of infrared images to identify a face of a human subject; measuring one or more infrared intensity values from the face of the human subject; and setting a pre-defined range based on the one or more infrared intensity values measured from the face of the human subject, wherein the pre-defined range includes infrared intensity values corresponding to human skin located within a depth range from the infrared camera that is illuminated by an infrared illumination, wherein the pre-defined range is obtained by previous training of a machine learning algorithm on one or more human training subjects located within the depth range from the infrared camera that is illuminated by the infrared illumination; identifying as an initial candidate foreground region within each infrared image of the plurality of infrared images the pixels exhibiting infrared intensity values within the pre-defined range; estimating a depth of surfaces within the initial candidate foreground region based on infrared intensity values of the pixels within the initial candidate foreground region; and expanding the initial candidate foreground region to an expanded candidate foreground region based on a body-model estimate of the face of the human subject seeded with the initial candidate foreground region and the depth of surfaces estimated within the initial candidate foreground region; identifying each pixel of each infrared image of the plurality of infrared images as either a foreground pixel or a background pixel based on a distance of that pixel relative to the expanded candidate foreground region; for some or all of the pixels of each infrared image of the plurality of infrared images identified as background pixels, modifying corresponding background pixels in the visible light image of the plurality of visible light images that is time-registered and spatially registered with that infrared image outputting the plurality of visible light images as a visible light video with each visible light image having modified background pixels. obtaining a plurality of infrared images forming an infrared video captured via an infrared camera; obtaining a plurality of visible light images forming a visible light video captured via a visible light camera, each visible light image of the plurality of visible light images being time-registered and spatially-registered with each infrared image of the plurality of infrared images; applying facial recognition to each infrared image of the plurality of infrared images to identify a face of a human subject; measuring one or more infrared intensity values from the face of the human subject; and setting a pre-defined range based on the one or more infrared intensity values measured from the face of the human subject, wherein the pre-defined range includes infrared intensity values corresponding to human skin located within a depth range from the infrared camera that is illuminated by an infrared illumination, wherein the pre-defined range is obtained by previous training of a machine learning algorithm on one or more human training subjects located within the depth range from the infrared camera that is illuminated by the infrared illumination; identifying as an initial candidate foreground region within each infrared image of the plurality of infrared images the pixels exhibiting infrared intensity values within the pre-defined range; estimating a depth of surfaces within the initial candidate foreground region based on infrared intensity values of the pixels within the initial candidate foreground region; and expanding the initial candidate foreground region to an expanded candidate foreground region based on a body-model estimate of the face of the human subject seeded with the initial candidate foreground region and the depth of surfaces estimated within the initial candidate foreground region; identifying each pixel of each infrared image of the plurality of infrared images as either a foreground pixel or a background pixel based on a distance of that pixel relative to the expanded candidate foreground region; for some or all of the pixels of each infrared image of the plurality of infrared images identified as background pixels, modifying corresponding background pixels in the visible light image of the plurality of visible light images that is time-registered and spatially registered with that infrared image outputting the plurality of visible light images as a visible light video with each visible light image having modified background pixels.