1. A system for background image subtraction comprising: a computing device having a processor and memory and coupled with a three-dimensional (3D) video camera, the processor programmed to receive a video feed from the camera, the video feed containing colored images of one or more subject that include depth information; the processor further programmed, for a colored image, to: segment pixels and corresponding depth information of the images into three different regions including foreground (FG), background (BG), and unclear (UC); categorize UC pixels as FG or BG using a function that considers the color and background history (BGH) information associated with the UC pixels and the color and BGH information associated with pixels near the UC pixels; examine the pixels marked as FG and apply temporal and spatial filters to smooth boundaries of the FG regions; construct a new image by overlaying the FG regions on top of a new background; display a video feed of the new image in a display device coupled with the computing device; and continually maintain the BGH.