Methods and systems are provided to determine a target tracking box that surrounds a moving target. The pixels that define an image within the target tracking box can be classified as background pixels, foreground pixels, and changing pixels which may include pixels of an articulation, such as a portion of the target that moves relatively to the target tracking box. Identification of background image pixels improves the signal-to-noise ratio of the image, which is defined as the ratio between the number of pixels belonging to the foreground to the number of changing pixels, and which is used to track the moving target. Accordingly, tracking of small and multiple moving targets becomes possible because of the increased signal-to-noise ratio.