Defects are detected in a reticle used in integrated circuit chip fabrication by obtaining digital image data corresponding to an image of the reticle. Typically, this is accomplished by scanning the reticle using a laser scanner. The digital image data are then processed according to predetermined criteria to identify defects. Such processing may include, for example, processing the digital image data in comparison to reference digital image data for the same or a similar portion of the reticle. Next, a response that would be produced if the reticle were to be utilized in a photolithographic system is simulated by processing the digital image data corresponding to the reticle.