1. An imaging method, comprising: obtaining an infrared image captured via an infrared camera; identifying an initial candidate foreground region within the infrared image that includes pixels exhibiting infrared intensity values within a pre-defined range; estimating depth values of surfaces within the initial candidate foreground region of the infrared image based on infrared intensity values of the pixels within the initial candidate foreground region of the infrared image; and expanding the initial candidate foreground region to an expanded candidate foreground region based on a body-model estimate seeded with the initial candidate foreground region and the depth values of the surfaces estimated within the initial candidate foreground region.