1. A method for processing depth information of a scene, the method comprising: receiving a depth image; generating a grid of voxels based on the depth image; determining whether one or more voxels in the grid are associated with a background by at least comparing a minimum depth value of the voxels in the grid with a reference plate comprising a depth history of the voxels in the grid; discarding the one or more voxels associated with the background to isolate voxels associated with a foreground object in the depth image; and processing the non-discarded voxels in the grid.