1. An apparatus for eliminating background noise from a security marker authenticating system comprising: a sensor which captures an image of a background with a security marker; a light source illuminating the security marker; wherein the sensor captures a plurality images of an optical response of the security marker; a computer which averages the plurality of optical response images; wherein the computer smoothes the background image; and wherein the computer subtracts the smoothed background image from the average of the plurality of optical response images.