1. A method for managing inventory, comprising: receiving, by a processor, a depth image video frame captured by a depth sensing device, wherein the depth sensing device comprises an image based depth sensing device comprising a red green blue depth (RGB-D) camera; determining, by the processor, pixels that are in a region of interest of the depth image video frame; determining, by the processor, that a number of pixels of the pixels that are in the region of interest containing motion is below a threshold; monitoring, by a processor, the region of interest to determine an inventory level based upon the depth image video frame when the number of pixels containing motion in the region of interest is below the threshold; calculating, by the processor, a change in a depth in the region of interest from the depth image video frame that is captured; monitoring, by the processor, the region of interest to identify different items that are within the depth image video frame using a red green blue (RGB) image captured from the RGB-D camera based on a comparison to a corresponding signature image stored in a database; identifying, by the processor, a particular item of the different items of the inventory that incurred the change in the depth of the region of interest; and determining, by the processor, a change in the inventory level associated with the change in the depth of the region of interest.