A method for operating a reticle inspection system includes training an analysis model of the reticle inspection system with a machine learning process, generating a difference threshold based on the machine learning process, storing a reference image, and generating a scan image of a reticle with the reticle inspection system. The method includes generating a relative difference value by comparing the scan image to the reference image. The method includes, if the relative difference value is less than the difference threshold, determining that the reticle is not defective. The method includes, if the relative difference value is greater than the difference threshold, determining that the reticle is defective.