1. A device for processing depth information of a scene, the device comprising: a processor; and a memory communicatively coupled to the processor when the device is operational, the memory bearing processor-executable instructions that, when executed upon the processor, cause the device to at least: receive a depth image of the scene; determine that one or more pixels in the depth image are associated with an environment of the depth image comprising determining a boundary around a target in the depth image and identifying at least a first pixel as within the boundary, the boundary being determined from depth history data; discard at least a second pixel outside the boundary to isolate the target in the depth image; and process the depth image with the target.