1. A computer-implemented method for filtering scratches from inspection results for a wafer, comprising: generating a defect candidate map for a wafer from images of the wafer generated by a wafer inspection system, wherein the defect candidate map comprises image data for potential defect candidates as a function of position on the wafer, and wherein generating the defect candidate map comprises applying a threshold to the images and determining that portions of the images having values above the threshold are the potential defect candidates; removing noise from the defect candidate map to generate a filtered defect candidate map; determining one or more characteristics of the potential defect candidates based on portions of the filtered defect candidate map corresponding to the potential defect candidates; determining if each of the potential defect candidates are scratches based on the one or more characteristics determined for each of the potential defect candidates; and separating the potential defect candidates determined to be the scratches from other defects in inspection results for the wafer generated by the wafer inspection system, wherein the generating, removing, determining the one or more characteristics, determining if each of the potential defect candidates are the scratches, and separating steps are performed by a computer system.