A defect inspection system for a specimen includes an image sensor and a defect inspection device. The image sensor is configured to capture a target image of the specimen that includes a flat portion and a curved portion extending from the flat portion along a first direction and having a curvature. The target image includes a first area corresponding to the flat portion of the specimen and a second area corresponding to the curved portion of the specimen. The defect inspection device is configured to determine a defect of the specimen based on the target image. The defect inspection device includes an image editor that is configured to enlarge a width of the second area along the first direction by a resize ratio.