1. A method, comprising: initializing a dimensioning system by: at a range camera, capturing one or more initial reference images of a measurement platform and surrounding area; at a processor: generating a reference depth map from each initial reference image; generating and storing to a memory a background model from the reference depth maps; testing the dimensioning system for a scene change by: at the range camera, capturing a subsequent image of the measurement platform and surrounding area; at the processor: generating a current depth map from the subsequent image; comparing each pixel of the current depth map with a corresponding pixel of the background model; and counting a number of pixels Pv of the current depth map that differ absolutely from the background model by more than the prescribed threshold THRESH 1 , and if the number of pixels Pv is greater than a threshold THRESH 2 , determining that a significant change in the image has occurred.