An exemplary method includes identifying defects in a first image among a series of images, by identifying a first portion of the first image at a first location in the first image, wherein a brightness of the first portion is different from a second portion at the first location in a previous image and a third portion at the first location in a subsequent image, by an amount exceeding a first threshold value, determining whether a first region of the first image that includes the first portion, matches a second region of the previous image and a third region of the subsequent image, wherein the second and third regions are at second and third locations displaced from the first location, and characterizing the first portion as a defect when the first region does not match the second and third regions.