1. An inventory control system for determining an inventory condition of objects stored in the system, the system comprising: at least one storage drawer, each storage drawer including a plurality of storage locations for storing objects; a data storage device storing reference data for each storage drawer, wherein the reference data includes, for each region of interest corresponding to each respective storage drawer, a reference image signature representing a pixel number distribution of the region of interest when a stored object is present, wherein the pixel number distribution includes a plurality of pixel numbers; and a data processor configured to: derive an image signature representing a pixel number distribution of a region of interest corresponding to a drawer using a captured image of the drawer; and determine an inventory condition of the drawer according to the stored reference data corresponding to the region of interest and the derived image signature representing the pixel number distribution of the region of interest in the captured image by matching each of the plurality of pixel numbers of the pixel number distribution in the stored reference image signature with the pixel number distribution of the region of interest in the captured image of the drawer.